SYSTEMS AND METHODS THAT UTILIZE A DUAL-DUTY
AGENT TO INCREASE VISCOUS HYDROCARBON
PRODUCTION FROM A SUBTERRANEAN FORMATION
FIELD OF THE DISCLOSURE
[0001] The present disclosure is directed generally to systems and methods for increasing production of viscous hydrocarbons from a subterranean formation, and more particularly to systems and methods that utilize a dual-duty agent to both dilute and increase the temperature of the viscous hydrocarbons, thereby decreasing the viscosity of the viscous hydrocarbons.
BACKGROUND OF THE DISCLOSURE
[0002] Subterranean formations may contain unconventional hydrocarbon reserves that may include high-viscosity and/or quasi-solid hydrocarbons, which may be referred to herein as viscous hydrocarbons. As an illustrative, non-exclusive example, bitumen that is present in oil sands formations may include a viscosity of at least 10,000 centipoise (cP) under reservoir conditions. Due to their high viscosity, these viscous hydrocarbons may be difficult to pump and/or otherwise produce from the subterranean formation.
[0003] Under certain conditions and/or with certain subterranean formations, it may be possible to remove these viscous hydrocarbons from the subterranean formation using mining and/or other ex situ processes. However, doing so often requires corresponding complex and/or expensive processes, and may yield less than a desired amount of the viscous hydrocarbons. For formations that are too deep to be mined using conventional ex situ processes, in situ processes_may be used. Accordingly, attempts have been made to decrease the viscosity of the viscous hydrocarbons in situ and thereby avoid some of the disadvantages of producing viscous hydrocarbons via ex situ processes. This decrease in viscosity may permit production of the viscous hydrocarbons through hydrocarbon wells that may extend within the subterranean formation.
[0004] A variety of in situ processes has been utilized to decrease the viscosity of these viscous hydrocarbons. Generally, these in situ processes fall into two distinct categories.
The first category includes processes that increase the temperature of the viscous hydrocarbons to decrease the viscosity of the viscous hydrocarbons. The second category includes processes that dilute the viscous hydrocarbons to decrease the viscosity of the viscous hydrocarbons. Accordingly, the first category of processes may be referred to herein as thermal processes, and the second category of processes may be referred to herein as dilution processes.
[0005] While both thermal processes and dilution processes may be utilized to increase production of viscous hydrocarbons from certain unconventional hydrocarbon reserves, both processes have inherent limitations. Thus, there exists a need for improved systems and methods for increasing viscous hydrocarbon production from a subterranean formation.
SUMMARY OF THE DISCLOSURE
[0006] Systems and methods for enhancing production of viscous hydrocarbons from a subterranean formation. The systems and methods include supplying a dual-duty agent and an oxidant to the subterranean formation and combusting a portion (which may be referred to herein as a combusted portion) of the dual-duty agent with the oxidant to heat a heated zone of the subterranean formation. The systems and methods further include flowing an uncombusted portion of the dual-duty agent through the heated zone to heat the uncombusted portion of the dual-duty agent and generate a heated dual-duty agent. The systems and methods also include contacting the viscous hydrocarbons with the heated dual-duty agent to generate heated and diluted hydrocarbons that have a lower viscosity than a viscosity of the viscous hydrocarbons.
[0007] In some embodiments, the systems and methods further include pre-heating the dual-duty agent prior to supplying the dual-duty agent to the subterranean formation. In some embodiments, the systems and methods further include producing the heated and diluted hydrocarbons from the subterranean formation. In some embodiments, a single well conveys the dual-duty agent and the oxidant to the subterranean Ibrmation and produces the heated and diluted hydrocarbons from the subterranean formation. In some embodiments, an injection well conveys the dual-duty agent and the oxidant to the subterranean formation, and a separate production well produces the heated and diluted hydrocarbons from the subterranean formation.
[0008] In some embodiments, the systems and methods further include initiating the supply of the oxidant to the subterranean formation and/or initiating the combusting based, at least in part, on the temperature of the heated zone, the temperature of the heated and diluted hydrocarbons, and/or the viscosity of the heated and diluted hydrocarbons. In some embodiments, the systems and methods further include ceasing the supplying of the oxidant while continuing the supplying of the dual-duty agent to the subterranean formation. In some embodiments, the ceasing may be based, at least in part, on the temperature of the heated zone, the temperature of the heated and diluted hydrocarbons, and/or combustion of a predetermined fraction of the dual-duty agent.
[0009] In some embodiments, the systems and methods further may include removing a portion of the viscous hydrocarbons from the heated zone prior to the combusting of the dual-duty agent. In some embodiments, this may include supplying a portion of the dual-duty agent to the subterranean formation to produce the diluted hydrocarbons prior to combusting a different, or subsequent, portion of the dual-duty agent. In some embodiments, this may include performing a cyclic solvent process (CSP), a heated solvent process, a heated vapour extraction (VAPEX) process, a non-heated VAPEX process, a steam-assisted gravity drainage (SAGD) process, a solvent-assisted steam-assisted gravity drainage (SA-SAGD) process, a steamflooding process, and/or an in situ combustion process to produce the diluted hydrocarbons prior to the combusting. In some embodiments, this may include producing a portion of the diluted hydrocarbons and/or the viscous hydrocarbons from the subterranean formation prior to the combusting of the dual-duty agent.
[0009a] Certain exemplary embodiments can provide a method of heating and diluting viscous hydrocarbons within a subterranean formation, the method comprising:
supplying a dual-duty agent comprising a diluent to the subterranean formation; supplying an oxidant to the subterranean formation; combusting a combusted portion of the dual-duty agent with the oxidant to heat a portion of the subterranean formation, with the portion of the subterranean formation forming a heated zone of the subterranean formation; flowing an uncombusted portion of the dual-duty agent at least one of through the heated zone and around the heated zone, wherein the flowing includes flowing to heat the uncombusted portion of the dual-duty agent and generate a heated dual-duty agent; and contacting the viscous hydrocarbons with the heated dual-duty agent to generate heated and diluted hydrocarbons which have a lower viscosity than the viscous hydrocarbons via dilution with the heated dual-duty agent.
[0009b] Certain exemplary embodiments can provide a method of heating and diluting viscous hydrocarbons within a subterranean formation, the method comprising:
supplying a dual-duty agent comprising a diluent to the subterranean formation; supplying an oxidant to the subterranean formation; combusting a combusted portion of the dual-duty agent with the oxidant to heat a portion of the subterranean formation, with this portion of the subterranean formation forming a heated zone of the subterranean formation; ceasing the supplying of the oxidant while continuing the supplying of the dual-duty agent to the subterranean formation;
flowing an uncombusted portion of the dual-duty agent through the heated zone to heat the uncombusted portion of the dual-duty agent and generate a heated dual-duty agent; and contacting the viscous hydrocarbons with the heated dual-duty agent to generate heated and diluted hydrocarbons which have a lower viscosity than the viscous hydrocarbons via dilution with the heated dual-duty agent.
[0009c] Certain exemplary embodiments can provide a method of heating and diluting viscous hydrocarbons within a subterranean formation, the method comprising:
continuously supplying a dual-duty agent comprising a diluent to the subterranean formation; periodically supplying an oxidant to the subterranean formation; combusting a combusted portion of the dual-duty agent with the oxidant in a heated zone of the subterranean formation during the periodically supplying; flowing an uncombusted portion of the dual-duty agent through the heated zone to heat the uncombusted portion of the dual-duty agent and generate a heated dual-duty agent; and contacting the viscous hydrocarbons with the heated dual-duty agent to generate heated and diluted hydrocarbons which have a lower viscosity than the viscous hydrocarbons via dilution with the heated dual-duty agent.
[0009d] Certain exemplary embodiments can provide a method of heating and diluting viscous hydrocarbons within a subterranean formation, the method comprising:
periodically supplying a dual-duty agent comprising a diluent to the subterranean formation; periodically supplying an oxidant to the subterranean formation; combusting a combusted portion of the dual-duty agent with the oxidant in a heated zone of the subterranean formation during the periodically supplying; flowing an uncombusted portion of the dual-duty agent through the heated zone to heat the uncombusted portion of the dual-duty agent and generate a heated dual-duty agent; and contacting the viscous hydrocarbons with the heated dual-duty agent to generate heated and diluted hydrocarbons which have a lower viscosity than the viscous hydrocarbons via dilution with the heated dual-duty agent.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Fig. 1 is a schematic cross-sectional view of an illustrative, non-exclusive example of a viscous hydrocarbon production assembly that may include and/or utilize the systems and methods according to the present disclosure.
[0011] Fig. 2 is a schematic transverse cross-sectional view of an illustrative, non-exclusive example of a combined injection and production wellbore that may form a portion 3a of the viscous hydrocarbon production assembly of Fig. I.
[0012] Fig. 3 is a schematic transverse cross-sectional view of an illustrative, non-exclusive example of separate injection and production wellbores that may form a portion of the viscous hydrocarbon production assembly of Fig. I.
[0013] Fig. 4 is a schematic representation of an illustrative, non-exclusive example comparing the hydrocarbon production vs. cycle number for a production-enhancing method according to the present disclosure with that of a prior art production-enhancing method.
[0014] Fig. 5 is a flowchart depicting methods according to the present disclosure of heating and diluting viscous hydrocarbons that are present within a subterranean formation.
3b
[0015] Fig. 6 is a flowchart depicting methods according to the present disclosure of enhancing production of viscous hydrocarbons from a subterranean formation.
DETAILED DESCRIPTION AND BEST MODE OF THE DISCLOSURE
[0016] Fig. 1 is a schematic cross-sectional view of an illustrative, non-exclusive example of a viscous hydrocarbon production assembly 10 that may include and/or utilize the systems and methods according to the present disclosure. The viscous hydrocarbon production assembly of Fig. 1 includes at least one well 12 that includes at least one wellbore 20 that defines a wellbore conduit 22. The wellbore conduit extends between a surface region 30 and a subterranean formation 42 that is present within a subsurface region 40. Figs.
2-3 provide schematic transverse cross-sectional views of wellbore(s) 20 of Fig. 1.
[0017] As illustrated in Fig. 1, viscous hydrocarbon production assembly 10 further includes a dual-duty agent supply system 50 that is configured to selectively supply a dual-duty agent 52, which also may be referred to herein as a dual-duty agent stream 52, through wellbore conduit 22 and to subterranean formation 42. Viscous hydrocarbon production assembly 10 also includes an oxidant supply system 60 that is configured to selectively supply an oxidant 62, which also may be referred to herein as an oxidant stream 62, through wellbore conduit 22 and to subterranean formation 42.
[0018] The viscous hydrocarbon production assembly further may include a control system 90 that is programmed and/or otherwise configured to control the operation of at least .. a portion of the viscous hydrocarbon production assembly. In addition, viscous hydrocarbon production assembly 10 also may include a hydrocarbon production system 86.
Hydrocarbon production system 86 additionally or alternatively may be referred to herein as a viscous hydrocarbon production system 86 and/or as a heated and diluted hydrocarbon production system 86, that is configured to produce heated and diluted hydrocarbons 49 from the subterranean formation. Heated and diluted hydrocarbons 49 also may be referred to herein as a heated and diluted hydrocarbon stream 49.
[0019] Dual-duty agent supply system 50, oxidant supply system 60, heated and diluted hydrocarbon production system 86, and control system 90 are illustrated as being separate and/or distinct from well 12 in Fig. 1. However, it is within the scope of the present disclosure that any suitable component of viscous hydrocarbon production assembly 10 may be integrated into and/or form a portion of any other suitable portion of the viscous hydrocarbon production assembly. As illustrative, non-exclusive examples, at least a portion of the dual-duty agent supply system, the oxidant supply system, the heated and diluted hydrocarbon production system, and/or the control system may be integrated into and/or located within one or more well(s) 12 and/or wellbore conduit(s) 22 thereof
[0020] Subterranean formation 42 may be any suitable structure that includes and/or contains one or more viscous hydrocarbons 46. As illustrative, non-exclusive examples, subterranean formation 42 may include and/or be an oil sands formation, a tar sands formation, and/or a bituminous sands formation that may contain viscous hydrocarbons 46.
Illustrative, non-exclusive examples of viscous hydrocarbons 46 include bitumen, tar, and/or other unconventional hydrocarbon reserves. These unconventional hydrocarbon reserves may include hydrocarbons with a viscosity that is too high to be produced from the subterranean formation using traditional primary and/or secondary hydrocarbon recovery operations without first decreasing the viscosity thereof. This may be due to the fact that these primary and/or secondary hydrocarbon recovery operations may rely upon a pressure head to flow hydrocarbons from the subterranean formation.
[0021] Subterranean formation 42 also may include reservoir solids 44, and viscous hydrocarbons 46 may be distributed between, adsorbed on, and/or adhered to the reservoir solids. Illustrative, non-exclusive examples of reservoir solids according to the present disclosure include sand, rock, a solid structure, and/or a matrix material that may be present within and/or define a portion of the subterranean formation.
[0022] Dual-duty agent supply system 50 may include any suitable structure that is configured to provide dual-duty agent 52 to subterranean formation 42 via wellbore conduit 22. As illustrative, non-exclusive examples, the dual-duty agent supply system may include one or more valves, pumps, compressors, pipes, and/or storage tanks that may be configured to store the dual-duty agent and/or to control a flow of the dual-duty agent between surface .. region 30 and subterranean formation 42. The dual-duty agent supply system also may include a pre-heater 56 that is configured to heat, or pre-heat, the dual-duty agent prior to supply of the dual-duty agent to the subterranean formation.
[0023] Illustrative, non-exclusive examples of dual-duty agents 52 according to the present disclosure, which additionally or alternatively may be referred to herein as dual-duty diluents 52, include any suitable fluid that is both flammable and/or combustible and that may function as a diluent for at least a portion of viscous hydrocarbons 46 that are contained within the subterranean formation. Thus, dual-duty agents 52 additionally or alternatively may be referred to herein as being soluble in viscous hydrocarbons 46, dissolving in viscous hydrocarbons 46, and/or decreasing the viscosity of viscous hydrocarbons 46.
More specific but still illustrative, non-exclusive examples of dual-duty agents 52 according to the present disclosure include methane, ethane, propane, butane, pentane, hexane, heptane, octane, nonane, decane, dimethyl ether, a normal or an isomeric alkane, a normal or an isomeric alkene, naphtha, natural gas condensate or condensates, gas plant condensate or condensates, and/or mixtures that include one or more of the above materials.
[0024] As discussed, dual-duty agent 52 may include and/or be a diluent, which also may be referred to herein as a filler, a dilutent, a thinner, and/or a diluting agent. Thus, the dual-duty agent may include and/or be a material that, when added to viscous hydrocarbons 46, decreases the viscosity thereof. This decrease in viscosity may provide for, permit, and/or enable flow of the viscous hydrocarbons within subterranean formation 42, flow of the viscous hydrocarbons within a pore space that may be present between reservoir solids 44 that form a portion of the subterranean formation, and/or flow of the viscous hydrocarbons from subterranean formation 42 to surface region 30 via wellbore conduit 22.
This decrease in viscosity also may include decreasing the viscosity of the viscous hydrocarbons such that the viscous hydrocarbons begin to flow within the subterranean formation and/or the wellbore conduit and/or decreasing the viscosity of the viscous hydrocarbons to decrease a magnitude of a driving force (such as a pressure differential) that is needed to permit flow of the viscous .. hydrocarbons through the subterranean formation and/or the wellbore conduit at a desired, or target, flow rate.
[0025] Oxidant supply system 60 may include any suitable structure that is configured to selectively supply oxidant 62 to subterranean formation 42 via wellbore conduit 22. As illustrative, non-exclusive examples, oxidant supply system 60 may include one or more .. pumps, compressors, valves, storage tanks, and/or fluid conduits that may be configured to retain and/or control the flow of oxidant 62, such as oxygen, air, oxygen-enriched air, or a chemical oxidant, to the subterranean formation.
[0026] Heated and diluted hydrocarbon production system 86 may include any suitable structure that is configured to convey heated and diluted hydrocarbons 49 from subterranean .. formation 42 via wellbore conduit 22. As illustrative, non-exclusive examples, heated and diluted hydrocarbon production system 86 may include and/or utilize any suitable pressure head, gravitational force, pump, and/or other structure to provide a motive force to convey heated and diluted hydrocarbons 49 from subterranean formation 42 into wellbore conduit 22 and/or through wellbore conduit 22, as well as from the subterranean formation to surface region 30.
[0027] Control system 90 may include any suitable structure that is adapted, configured, designed, selected, and/or programmed to control the operation of at least a portion of viscous hydrocarbon production assembly 10. As an illustrative, non-exclusive example, control system 90 may include and/or be in communication with one or more detectors 92 that may be configured to detect one or more properties of viscous hydrocarbon production assembly and/or any suitable component thereof and/or material that is contained therein.
10 Illustrative, non-exclusive examples of properties that may be detected by detectors 92 include any suitable temperature, pressure, chemical composition, and/or flow rate of viscous hydrocarbons 46, subterranean formation 42, heated and diluted hydrocarbons 49, and/or dual-duty agent 52.
[0028] As another illustrative, non-exclusive example, control system 90 may control the operation of the viscous hydrocarbon production assembly based, at least in part, on the detected properties. As illustrative, non-exclusive examples, this may include controlling a flow rate of dual-duty agent 52 and/or oxidant 62. As another illustrative, non-exclusive example, this may include initiating and/or increasing a flow of oxidant 62 responsive to detecting a temperature that is less than a threshold temperature. As yet another illustrative, non-exclusive example, this may include ceasing and/or decreasing the flow of oxidant 62 responsive to detecting a temperature that is greater than a threshold temperature. Additional illustrative, non-exclusive examples of control strategies for controller 90 are discussed in more detail herein with reference to methods 200, 300 of Figs. 5-6.
[0029] As illustrated in Fig. 1, detectors 92 may be associated with any suitable portion of the viscous hydrocarbon production assembly. As illustrative, non-exclusive examples, one or more detectors 92 may be associated with, located within, and/or form a portion of well 12, dual-duty agent supply system 50, oxidant supply system 60, heated and diluted hydrocarbon production system 86, wellbore conduit 22, and/or subterranean formation 42.
Illustrative, non-exclusive examples of detectors 92 include any suitable temperature detector, pressure detector, differential pressure detector, chemical composition detector, and/or viscometer. Illustrative, non-exclusive examples of properties that may be detected by detectors 92 include any suitable temperature, pressure, differential pressure, chemical composition, and/or viscosity.
[0030] It is within the scope of the present disclosure that viscous hydrocarbon production assembly 10 may be utilized and/or controlled in any suitable manner and that this may include automated and/or manual control. As illustrative, non-exclusive examples, control system 90 may control the operation of viscous hydrocarbon production assembly 10 using methods 200, 300 that are discussed in more detail herein with reference to Figs. 5-6.
As another illustrative, non-exclusive example, at least a portion of the operation of the viscous hydrocarbon production assembly may be controlled manually and/or by an operator of the viscous hydrocarbon production assembly. This also may include performing at least a .. portion of methods 200, 300 that are discussed in more detail herein.
[0031] With continued reference to Figs. 1-3, viscous hydrocarbon production assembly 10 may be configured to both heat and dilute viscous hydrocarbons 46 that may be present within subterranean formation 42, thereby decreasing the viscosity of the viscous hydrocarbons and increasing a flow of the viscous hydrocarbons through subterranean formation 42 to wellbore conduit 22 and/or through wellbore conduit 22 to surface region 30.
Thus, viscous hydrocarbon production assembly 10 may increase recovery and/or production of viscous hydrocarbons that might otherwise be difficult and/or costly to remove (or remove by pumping) from subterranean 42 due to the high viscosity thereof.
[0032] Viscous hydrocarbon production assembly 10 may include a well 12 that may function as both an injection well 14 and a production well 16, with the operation of injection well 14 and production well 16 being discussed in more detail herein. This is illustrated in Fig. 1 by first well 26. Under these conditions, and as illustrated in dashed lines in Fig. 1, the viscous hydrocarbon production assembly further may include an auxiliary well 18 that extends from surface region 30. At least a portion of auxiliary well 18 may extend adjacent to first well 26, may be proximal to first well 26, may be in fluid communication with first well 26, and/or may intersect first well 26 within subterranean formation 42.
As also illustrated in Fig. 1, auxiliary well 18 (when present) optionally may convey dual-duty agent 52 and/or oxidant 62 from surface region 30 to first well 26. Additionally or alternatively, auxiliary well 18 may include and/or be a vent well that is configured to convey a combustion product stream 76 from first well 26 to surface region 30.
[0033] When auxiliary well 18 conveys at least two of dual-duty agent 52, oxidant 62, and combustion product stream 76 between the surface region and the first well, the auxiliary well may include and/or define a plurality of respective wellbore conduits 22, such as through inclusions of a plurality of pipes therein. This may permit conveying the respective materials without mixing therein and/or may permit mixing of the respective materials within a desired portion, or region, of the auxiliary well. Additionally or alternatively, the respective plurality of wellbore conduits 22 may be defined within first well 26 and/or a second well 28, which is discussed in more detail herein.
[0034] However, the viscous hydrocarbon production assembly also may include more than one well 12. This is illustrated in Fig. 1 by first well 26 and optional second well 28.
When the viscous hydrocarbon production assembly includes both first well 26 and second well 28, one well (such as first well 26) may be production well 16 and one well (such as second well 28) may be injection well 14.
[0035] Regardless of whether the viscous hydrocarbon production assembly includes one well, two wells, or more than two wells. production well 16 may be configured to produce heated and diluted hydrocarbons 49 from subterranean formation 42 to surface region 30. In .. addition, injection well 14 may be configured to provide dual-duty agent 52 and oxidant 62 to subterranean formation 42, thereby generating heated and diluted hydrocarbons 49, as discussed in more detail herein.
[0036] It is also within the scope of the present disclosure that viscous hydrocarbon production assembly 10 may include more than two wells. As illustrative, non-exclusive examples, the viscous hydrocarbon production assembly may include 3 wells, 4 wells, 5 wells, 6 wells, 7 wells, 8 wells, or more than 8 wells. When the viscous hydrocarbon production assembly includes a plurality of wells 12, it is within the scope of the present disclosure that each well may function as both an injection well 14 and a production well 16.
However, it is also within the scope of the present disclosure that a first portion of wells 12 may be injection wells 14, while a second portion of wells 12 may be production wells 16, and a number of injection wells 14 may be less than, equal to, or greater than a number of production wells 16.
[0037] Well(s) 12 may include any suitable hydrocarbon well and may include any suitable orientation within subsurface region 40. As illustrative, non-exclusive examples, well(s) 12 may include a vertical portion, a deviated portion, and/or a horizontal portion.
When well(s) 12 include the horizontal portion, the horizontal portion may extend within subterranean formation 42, as illustrated in Fig. 1.
[0038] Regardless of the particular well configuration and the presence of one well, two wells, or more than two wells within viscous hydrocarbon production assembly 10, injection well 14 may be configured to convey dual-duty agent 52 and oxidant 62 to the subterranean formation. As discussed in more detail herein with reference to methods 200 and 300, .. oxidant 62 may be mixed with a first portion of dual-duty agent 52 within well 12 to generate a combustible mixture 74 of the dual-duty agent and the oxidant. Combustible mixture 74 may be combusted within a heated zone 70 that is present within subterranean formation 42, thereby heating heated zone 70, and an ignition source 72 may initiate combustion of combustible mixture 74 within the heated zone.
[0039] The first portion of dual-duty agent 52 also may be referred to herein as the combusted portion of dual-duty agent 52, the portion of dual-duty agent 52 that is combusted within heated zone 70, and/or the portion of dual-duty agent 52 that is to be combusted. The first portion of the dual-duty agent includes a portion, fraction, or percentage of dual-duty agent 52 (and/or a flow or stream thereof) that is supplied to heated zone 70 with, concurrently with, and/or in parallel to supply of oxidant 62 to the heated zone. Thus, the combusted portion of dual-duty agent 52 combines with oxidant 62 to form combustible mixture 74, which is subsequently combusted within the heated zone. The combusted portion of dual-duty agent 52 may not be premixed with oxidant 62 within wellbore 20 of well 12 and/or may not be mixed with oxidant 62 prior to being received within heated zone 70.
[0040] Subsequent to combustion of combustible mixture 74, flow of oxidant 62 to subterranean formation 42 may be stopped, which may stop and/or cease combustion of dual-duty agent 52 therein (such as due to the lack of oxidant within the subterranean formation).
This is discussed in more detail herein with reference to methods 200 and 300.
However, flow of a second portion of dual-duty agent 52 through injection well 14 may continue. The second portion of dual-duty agent 52 also may be referred to herein as an uncombusted portion of dual-duty agent 52 and/or as a portion of dual-duty agent 52 that is not combusted within heated zone 70.
[0041] The second portion of the dual-duty agent includes a portion, fraction, and/or percentage of the dual-duty agent (and/or a flow and/or stream thereof) that is supplied to injection well 14, subterranean formation 42, and/or heated zone 70 prior to supply of oxidant 62 to the heated zone, after supply of oxidant 62 to the heated zone, and/or when oxidant 62 is not being supplied to the heated zone. Additionally or alternatively, the second portion of dual-duty agent 52 also may include a fraction of the dual-duty agent that is present within combustible mixture 74 but that does not combust within heated zone 70, such as due to incomplete combustion of the dual-duty agent that is present within combustible mixture 74.
[0042] The second portion of the dual-duty agent may flow through heated zone 70 and be heated therein before flowing out of the heated zone as a heated dual-duty agent 54, which also may be referred to herein as a heated dual-duty agent stream 54. Heated dual-duty agent 54 may contact viscous hydrocarbons 46 within subterranean formation 42, thereby producing heated and diluted hydrocarbons 49.
[0043] Heated zone 70 may include and/or be any suitable portion of and/or location within subsurface region 40 and/or subterranean formation 42. As an illustrative, non-exclusive example, heated zone 70 may include a portion of well 12, a portion of wellbore 20, and/or wellbore conduit 22 thereof that extends within subterranean formation 42.
Additionally or alternatively, heated zone 70 may include a portion of subterranean formation 42 that is away from, adjacent, and/or in close proximity to, well 12. Heated zone 70 may include reservoir solids 44 with void or pore space therein that may be heated by combustion therein. In addition, reservoir solids 44 that are adjacent to, are proximal to, and/or are in thermal contact with heated zone 70 also may be heated by this combustion.
[0044] Heated zone 70 may be placed away from the well 14 and/or well 16 so as not to expose the well to excessive heat emanating from the heated zone 70. To carry the heat from .. heated zone 70 to the parts of subterranean formation 42 where heat is needed, a heat pipe 78 may be installed in and/or around heated zone 70. Although not required to all embodiments, the heat pipe, when present, may include and/or be a latent heat transferring device that does not include any moving parts, such as a sealed heat transfer device that contains a heat transfer fluid that boils at a lower temperature than that of formation 42 and/or heated zone 70. The heat transfer fluid at an end of the tube that is closer to heated zone 70 may vaporize and extract its latent heat of vaporization from heated zone 70. When this vapour reaches a cooler end of the heat pipe, it may condense and transfer the latent heat to the zone away from zone 70.
[0045] The heat pipe may be vertical and/or horizontal. A horizontal metal wick (wire mesh) may be placed inside the pipe to transfer the condensed transfer fluid to the hotter end by capillary action. Auxiliary well 18 in Fig. 1 and/or another auxiliary well may act as and/or include the heat pipe. Additionally or alternatively, a lateral heat pipe may be drilled from auxiliary well 18, injection well 14 and/or production well 16. The uncombusted portion of the dual-duty agent may be heated by the heat transferred from heated zone 70 by the heat pipe, with or without traversing through the heated zone.
[0046] Heated dual-duty agent 54 may flow through subterranean formation 42 and contact viscous hydrocarbons 46 that are present therein, such as in a heat transfer zone 80 thereof. Upon contacting the viscous hydrocarbons, the dual duty agent may both dilute the viscous hydrocarbons and transfer thermal energy to the viscous hydrocarbons (i.e., heat the viscous hydrocarbons) to generate heated and diluted hydrocarbons 49. As discussed herein, heated and diluted hydrocarbons 49 may have a viscosity that is significantly less than a viscosity of viscous hydrocarbons 46, thereby permitting the heated and diluted hydrocarbons to flow within subterranean formation 42 to wellbore conduit 22 of production well 16 and/or through wellbore conduit 22 of production well 16 to surface region 30.
[0047] As discussed, heated and diluted hydrocarbons 49 may include viscous hydrocarbons 46 that have been heated by, and diluted with, heated dual-duty agent 54 to decrease the viscosity thereof. Thus, heated and diluted hydrocarbons 49 may have a temperature, or average temperature, that is greater than an ambient temperature within the subterranean formation prior to combustion of dual-duty agent 52 and oxidant 62 therein and/or greater than a temperature of the viscous hydrocarbons prior to contact with heated dual-duty agent 54. Additionally or alternatively, heated and diluted hydrocarbons 49 may have a temperature of at least 15 C, at least 20 C, at least 25 C, at least 30 C, at least 35 C, at least 40 C, at least 45 C, at least 50 C, at least 55 C, at least 60 C, at least 65 C, at least 70 C, at least 75 C, at least 80 C, at least 85 C, at least 90 C, at least 95 C, or at least 100 C.
[0048] Additionally or alternatively, heated and diluted hydrocarbons 49 may have a viscosity, or average viscosity, that is less than an average viscosity of the viscous hydrocarbons prior to combustion of dual-duty agent 52 and oxidant 62 within the subterranean formation and/or less than a viscosity of the viscous hydrocarbons prior to contact with heated dual-duty agent 54. As illustrative, non-exclusive examples, the viscosity of heated and diluted hydrocarbons 49 may be at least 2, at least 3, at least 4, at least 5, at least 10, at least 25, at least 50, at least 100, at least 250, at least 500, at least 750, or at least 1000 times lower than the average viscosity of the viscous hydrocarbons prior to combustion of dual-duty agent 52 and oxidant 62 within the subterranean formation and/or prior to contact with heated dual-duty agent 54.
[0049] As discussed, heated and diluted hydrocarbons 49 include viscous hydrocarbons 46 and heated dual-duty agent 54. It is within the scope of the present disclosure that the heated and diluted hydrocarbons also may include one or more additional materials. As an illustrative, non-exclusive example, combustion of dual-duty agent 52 and oxidant 62 may generate one or more combustion products, such as water and/or carbon dioxide.
These combustion products may diffuse and/or flow within subterranean formation 42 and may absorb within, may dissolve within, and/or may dilute viscous hydrocarbons 46 and/or heated and diluted hydrocarbons 49.
[0050] Thus, the heated and diluted hydrocarbons further may include the combustion products. Mixing of the combustion products into and/or dissolution of the combustion products within viscous hydrocarbons 46 and/or heated and diluted hydrocarbons 49 further may decrease the viscosity of the generated heated and diluted hydrocarbons.
As an illustrative, non-exclusive example, the water may transfer a significant amount of thermal energy to the heated and diluted hydrocarbons (through condensation from steam that is generated during the combustion). As another illustrative, non-exclusive example, the carbon dioxide may act as a further diluent for the viscous hydrocarbons.
[0051] As discussed, and illustrated in Figs. 1 and 2, first well 26 may be both injection well 14 and production well 16. Under these conditions, viscous hydrocarbon production assembly 10 may be configured to provide both dual-duty agent 52 and oxidant 62 to subterranean formation 42, producing combustible mixture 74 therein, for a first supply time.
During the first supply time, combustible mixture 74 may be combusted within heated zone 70, thereby heating the heated zone.
[0052] Subsequently, the viscous hydrocarbon production assembly may cease supplying the oxidant but continue supplying the dual-duty agent to the subterranean formation, thereby ceasing the combustion within heated zone 70, for a second supply time. During the second supply time, the dual-duty agent may flow through the heated zone and be heated therein to generate heated dual-duty agent 54. The heated dual-duty agent may contact viscous hydrocarbons 46, thereby producing heated and diluted hydrocarbons 49. The second supply time may be greater than the first supply time. Additionally or alternatively, the viscous hydrocarbon production assembly may convey a greater volume of the dual-duty agent to the subterranean formation during the second supply time than was conveyed to the subterranean formation during the first supply time.
[0053] Subsequent to the second supply time, the viscous hydrocarbon production assembly may cease supplying the dual-duty agent to the subterranean formation. Upon ceasing the supply of the dual-duty agent to the subterranean formation, pressure within subterranean formation 42 that may be generated during the first supply time and/or the second supply time may provide a motive force for flow of heated and diluted hydrocarbons 49 from the subterranean formation into wellbore conduit 22 and/or through the wellbore conduit to surface region 30 as a produced heated and diluted hydrocarbon stream 88.
Heated and diluted hydrocarbon production system 86 may control the production of produced heated and diluted hydrocarbon stream 88 from the production well.
[0054] Alternatively, and as also discussed, and illustrated in Figs. 1 and 3, viscous hydrocarbon production assembly 10 may include more than one well 12, such as separate production 16 and injection 14 wells, with first well 26 and second well 28 respectively providing a more specific illustrative, non-exclusive example of such a configuration. Under these conditions, viscous hydrocarbon production assembly 10 may be configured to continuously, or at least substantially continuously, supply dual-duty agent 52 to the subterranean formation via injection well 14 and to selectively, intermittently, and/or periodically supply oxidant 62 to injection well 14.
[0055] When oxidant 62 is supplied to the injection well, the oxidant may mix with the combusted portion of the dual-duty agent therein, thereby producing combustible mixture 74, and the combustible mixture may be ignited within heated zone 70. When oxidant 62 is not supplied to the injection well, the uncombusted portion of the dual-duty agent may flow through the heated zone and be heated before contacting viscous hydrocarbons 46 to generate heated and diluted hydrocarbons 49.
[0056] Concurrently, heated and diluted hydrocarbons 49 may flow through subterranean formation 42 to wellbore conduit 22 of production well 16. The heated and diluted hydrocarbons may then flow through production well 16 to surface region 30, and flow thereof may be controlled by heated and diluted hydrocarbon production system 86.
[0057] When viscous hydrocarbon production assembly 10 includes separate injection wells 14 and production wells 16, such as second well 28 and first well 26, respectively, at least a parallel portion of injection well 14 may be parallel to, or at least substantially parallel to, a parallel portion of production well 16, as illustrated in Figs. 1 and 3.
In addition, and also as illustrated in Figs. 1 and 3, the parallel portion of injection well 14 may be at least substantially horizontal and may be located vertically, or at least substantially vertically, above the parallel portion of production well 16, which also may be at least substantially horizontal. This may permit heated and diluted hydrocarbons 49 that are generated by introduction of heated dual-duty agent 54 into injection well 14 to flow under the influence of gravity within subterranean formation 42 to wellbore conduit 22 of production well 16.
[0058] It is within the scope of the present disclosure that, as discussed in more detail herein with reference to methods 200, 300, viscous hydrocarbon production assembly 10 further may include and/or utilize additional production-enhancing processes in combination with the production-enhancing processes that are disclosed herein. As illustrative, non-exclusive examples, and when the viscous hydrocarbon production assembly includes a single well 12 that functions as both injection well 14 and production well 16 (such as first well 26 of Figs. 1 and 2), the systems and methods disclosed herein further may include and/or be utilized with any suitable traditional cyclic production-enhancing process, such as a cyclic solvent process (CSP) and/or cyclic steam injection (CSS). As additional illustrative, non-exclusive examples, and when the viscous hydrocarbon production assembly includes separate injection 14 and production 16 wells (such as second well 28 and first well 26, respectively, of Has. 1 and 3), the systems and methods disclosed herein further may include and/or be utilized with any suitable traditional continuous, or quasi-continuous, production-.. enhancing process, such as steam-assisted gravity drainage (SAGD), solvent-assisted steam-assisted gravity drainage (SA-SAGD), steamflooding, heated solvent, heated vapor extraction (VAPEX), and/or non-heated vapor extraction (VAPEX).
[0059] In addition, and as discussed in more detail herein with reference to methods 200, 300, it is also within the scope of the present disclosure that the systems and methods disclosed herein may be combined with the cyclic and/or continuous production-enhancing processes in any suitable manner. As an illustrative, non-exclusive example, one or more of the traditional production-enhancing processes may be an initial, first, or primary production-enhancing process that is performed within subterranean formation 42 prior to performing methods 200, 300. Under these conditions, methods 200, 300 may be referred to herein as subsequent, second, and/or secondary production-enhancing processes.
[0060] Additionally or alternatively, one or more of the traditional production-enhancing processes may be a subsequent, second, and/or secondary production-enhancing process that is performed within subterranean formation 42 after performing methods 200, 300. Under these conditions, methods 200, 300 may be referred to herein as primary, first, and/or initial production-enhancing processes.
[0061] Performing methods 200, 300 in addition to and/or in place of the traditional cyclic and/or continuous production-enhancing processes that are discussed above may provide significant benefits over performing only the traditional production-enhancing processes. As an illustrative, non-exclusive example, the traditional production-enhancing processes often may generate two liquid hydrocarbon phases that include viscous hydrocarbons 46, such as a light, or upper, phase and a heavy, or lower, phase.
[0062] The light phase that is produced by a traditional production-enhancing process may be readily produced from the subterranean formation without further processing.
However, the heavy phase produced by such a process may be difficult to remove from the subterranean formation due to a high viscosity of the heavy phase. Thus, it may be necessary to either leave the heavy phase within the subterranean formation or perform additional production-enhancing processes, such as injection of a supplemental, or heavy, diluent (and/or dual duty agent) into the subterranean formation, to further decrease the viscosity of the heavy phase. Leaving the heavy phase in the formation may decrease the overall viscous hydrocarbons production from the subterranean formation and/or decrease a proportion of the viscous hydrocarbon in place that may be produced from the subterranean formation.
Likewise, performing additional production-enhancing processes may increase a cost associated with producing the viscous hydrocarbons from the subterranean formation.
[0063] In contrast, the systems and methods disclosed herein, when performed alone and/or in conjunction with the traditional production-enhancing process, may decrease, suppress, and/or eliminate formation of the heavy phase. This suppression of formation of the heavy phase may be due to the concurrent heating and diluting of viscous hydrocarbons 46 to produce heated and diluted hydrocarbons 49 that may be accomplished with the systems and methods that are disclosed herein.
[0064] As another illustrative, non-exclusive example, it may be difficult and/or impossible to control the temperature of the subterranean formation using the traditional production-enhancing processes due to a lack of heat generation and/or an inconsistent/unpredictable heat generation thereby. In contrast, the systems and methods disclosed herein provide for selective supply of oxidant 62 to the subterranean formation to control the temperature thereof. This may decrease a potential for damage to the subterranean formation, damage to the viscous hydrocarbon production assembly by maintaining the temperature of the subterranean formation below an upper threshold temperature, and/or formation of undesired combustion products within the subterranean formation. As an illustrative, non-exclusive example, a flow rate of oxidant 62 may be decreased and/or stopped to decrease the temperature of the subterranean formation. As another illustrative, non-exclusive example, the flow rate of oxidant 62 may be initiated and/or increased to increase the temperature of the subterranean formation.
[0065] As another illustrative, non-exclusive example, it may be difficult to control the combustion products that may be produced during a traditional in situ combustion process.
In contrast, the dual-duty agent according to the present disclosure may be selected such that the combustion products thereof are primarily water/steam and carbon dioxide.
[0066] As discussed, the systems and methods disclosed herein may be used in combination with more traditional production-enhancing processes to improve the overall production of viscous hydrocarbons from the subterranean formation. Fig. 4 is a schematic representation of an illustrative, non-exclusive example comparing the hydrocarbon production vs. time (or cycle number) for a production-enhancing process 98 according to the present disclosure with that of a prior art production-enhancing process 96.
Both process 96 and process 98 utilize a single well for both injection of and production from the subterranean formation (such as first well 26 of Figs. 1 and 2).
[0067] Process 96 is a traditional cyclic solvent process, in which a diluent is injected into a wellbore that extends within the subterranean formation for an injection time. The diluent contacts and dilutes viscous hydrocarbons that are present within the subterranean formation. Subsequently, supply of the diluent to the subterranean formation is stopped, and the viscous hydrocarbons are produced from the subterranean formation for a production time. In Fig. 4, the process has been repeated a total of seven cycles, and the cumulative hydrocarbon production from the subterranean formation is shown to increase as a result of each cycle.
[0068] Process 98 is substantially similar to process 96 for cycles 1-4 and 6-7. However, at the beginning of cycle 5, the diluent is utilized as a dual-duty agent.
Thus, a combusted portion of the diluent is combusted within a heated zone of the subterranean formation using the systems and methods that are disclosed herein. Subsequently, an uncombusted portion of the diluent is flowed through the heated zone and into the subterranean formation. As discussed, this uncombusted portion of the diluent is heated by flow through the heated zone and subsequently heats and dilutes the viscous hydrocarbons that are present within the subterranean formation, thereby increasing an overall efficiency of the production-enhancing process.
[0069] This is illustrated by the increased cumulative hydrocarbon production that is shown in Fig. 4 for process 98 when compared to process 96. It is noteworthy that increased cumulative hydrocarbon production is observed during cycles 5, 6, and 7 despite the fact that the diluent is only combusted at the beginning of cycle 5, with cycles 6 and 7 being cycles of the traditional cyclic solvent process.
[0070] Fig. 5 is a flowchart depicting methods 200 according to the present disclosure of heating and diluting viscous hydrocarbons that are present within a subterranean formation.
Methods 200 may include removing viscous hydrocarbons from a heated zone at 205 and/or pre-heating a dual-duty agent at 210. Methods 200 include supplying the dual-duty agent to the subterranean formation at 215, supplying an oxidant to the subterranean formation at 220, and combusting a combusted portion of the dual-duty agent and the oxidant in a heated zone at 225. Methods 200 further may include ceasing the supplying of the oxidant while continuing the supplying of the dual-duty agent at 230. In addition, methods 200 include flowing an uncombusted portion of the dual-duty agent through the heated zone to generate a heated dual-duty agent at 235 and thermally and/or physically contacting the heated dual-duty agent with the viscous hydrocarbons to generate heated and diluted hydrocarbons at 240.
Methods 200 further may include producing the heated and diluted hydrocarbons from the subterranean formation at 245 and/or repeating the method at 250.
[0071] Removing the viscous hydrocarbons from the heated zone at 205 may include removing a portion, a substantial portion, a majority, or substantially all of the viscous hydrocarbons from a portion of the subterranean formation that will include the heated zone.
It is within the scope of the present disclosure that the removing may be accomplished in any suitable manner. As an illustrative, non-exclusive example, the removing may include producing the viscous hydrocarbons from the heated zone using any of the systems and methods that are disclosed herein.
[0072] Pre-heating the dual-duty agent at 210 may include pre-heating the dual-duty agent prior to the supplying at 215. It is within the scope of the present disclosure that the pre-heating may be accomplished in any suitable manner. As an illustrative, non-exclusive example, a pre-heater may be utilized to pre-heat the dual-duty agent. As another illustrative, non-exclusive example, the pre-heating may include pre-heating the dual-duty agent in a surface region that is proximate to a wellbore that extends between the surface region and the subterranean formation. As yet another illustrative, non-exclusive example, the pre-heating may include solar pre-heating. Still further illustrative, non-exclusive examples include pre-heating the dual-duty agent with hot fluid recovered from the subterranean formation, with electrical heating, with microwave heating, with infrared heating, with heat derived (and/or otherwise generated) by burning a portion of the dual-duty agent, and/or with heat derived (and/or otherwise generated) by burning a fossil fuel. When a portion of the dual-duty agent is burned (or otherwise combusted) to generate heat for pre-heating additional portions of the dual-duty agent, this portion may be referred to as a pre-heating portion and/or a pre-combusted portion of the dual-duty agent.
[0073] Supplying the dual-duty agent to the subterranean formation at 215 may include .. flowing and/or conveying the dual-duty agent through the wellbore and from the surface region to the subterranean formation. It is within the scope of the present disclosure that the dual-duty agent may be supplied continuously, or at least substantially continuously, to the subterranean formation. Alternatively, it is also within the scope of the present disclosure that the dual-duty agent may be supplied intermittently, periodically, and/or cyclically to the subterranean formation. As an illustrative, non-exclusive example, and as discussed in more detail herein, the supplying the dual-duty agent may be stopped and/or ceased responsive to, prior to, and/or during the producing at 245. However, and as also discussed herein, at least a portion of the dual-duty agent is supplied to the subterranean formation subsequent to the supplying the oxidant at 220 and the combusting at 225.
[0074] It is within the scope of the present disclosure that supplying the dual-duty agent may include supplying any suitable dual-duty agent, illustrative, non-exclusive examples of which are discussed in more detail herein, in any suitable form. As an illustrative, non-exclusive example, supplying the dual-duty agent may include supplying a gaseous, vaporous, and/or liquid dual-duty agent to the subterranean formation. As another illustrative, non-exclusive example, and when the dual-duty agent is supplied to the subterranean formation as a liquid, methods 200 further may include vaporizing the dual-duty agent within the subterranean formation to generate a vaporous dual-duty agent.
[0075]
Supplying the oxidant to the subterranean formation at 220 may include selectively, periodically, and/or intermittently supplying the oxidant to the subterranean formation. As an illustrative, non-exclusive example, supplying the oxidant to the subterranean formation at 220 may be performed concurrently with and/or responsive to a demand and/or desire for the combusting at 225. It is within the scope of the present disclosure that supplying the oxidant to the subterranean formation further may include mixing the oxidant with the combusted portion of the dual-duty agent to generate a combustible mixture of the dual-duty agent and the oxidant. The mixing may be performed in any suitable location, such as in the wellbore, in the subterranean formation, and/or in the heated zone. In this regard, it also is within the scope of the disclosure that the dual-duty agent and the oxidant may not be mixed in the wellbore, but that they may be mixed after being supplied to the subterranean formation and/or to the heated zone thereof.
[0076]
Combusting the combusted portion of the dual-duty agent and the oxidant at 225 may include combusting to heat the heated zone of the subterranean formation.
As discussed, the combusted portion of the dual-duty agent also may be referred to herein as a first portion of the dual-duty agent, a portion of the dual-duty agent that is combusted within the heated zone, and/or a portion of the dual-duty agent that is to be combusted. It is within the scope of the present disclosure that the combusting further may include igniting the combustible mixture of the dual-duty agent and the oxidant within the heated zone, such as by actuating an ignition source that is present within the heated zone.
[0077] As discussed, the combusting at 225 may generate a gaseous combustion product, which may include steam, water, and/or carbon dioxide, and methods 200 further may include retaining the gaseous combustion product within the subterranean formation. This may increase a pressure within the subterranean formation, thereby providing a driving force for production of the heated and diluted hydrocarbons from the subterranean formation at 245 and/or may further heat and/or dilute the viscous hydrocarbons.
[0078] It is within the scope of the present disclosure that the combusting at 225 may include combusting a fuel stream that includes the combusted portion of the dual-duty agent, as well as one or more additional materials that may be present within the heated zone, such as viscous hydrocarbons. As an illustrative, non-exclusive example, the dual-duty agent may comprise a majority, at least 60 wt%, at least 65 wt%, at least 70 wt%, at least 75 wt%, at least 80 wt%, at least 85 wt%, at least 90 wt%, at least 95 wt%, at least 96 wt%, at least 97 wt%, at least 98 wt%, or at least 99 wt% of the fuel stream. As another illustrative, non-exclusive example, the additional materials may comprise less than 40 wt%, less than 35 wt%, less than 30 wt%, less than 25 wt%, less than 20 wt%, less than 15 wt%, less than 10 wt%, less than 5 wt%, less than 4 wt%, less than 3 wt%, less than 2 wt%, or less than 1 wt%
of the fuel stream.
[0079] As discussed, the supplying the dual-duty agent at 215 may include supplying the dual-duty agent to the subterranean formation independently from the supplying the oxidant to the subterranean formation at 220 and/or the combusting at 225.
Additionally or alternatively, the supplying the dual-duty agent at 215 may be performed prior to, during, and/or subsequent to the supplying the oxidant at 220 and/or the combusting at 225, and the supplying the oxidant at 220 and/or the combusting at 225 may be initiated based upon any suitable criteria and/or combination of criteria.
[0080] As illustrative, non-exclusive examples, the supplying at 220 and/or the combusting at 225 may be initiated based, at least in part, on a selected and/or predetermined oxidant supply time and/or period. As another illustrative, non-exclusive example, and when the oxidant is supplied to the subterranean formation periodically, the supplying at 220 and/or the combusting at 225 may be initiated based, at least in part, on passage of a threshold elapsed time since a last and/or prior time that the oxidant was supplied to the subterranean formation.
[0081] As yet another illustrative, non-exclusive example, the supplying at 220 and/or the combusting at 225 may be initiated based, at least in part, on a temperature of the heated zone. This may include initiating the supplying at 220 and/or the combusting at 225 to maintain the temperature of the heated zone above a threshold lower heated zone temperature, illustrative, non-exclusive examples of which include temperatures of greater than 15 C, greater than 20 C, greater than 25 C, greater than 30 C, greater than 35 C, greater than 40 C, greater than 50 C, greater than 60 C, greater than 70 C, greater than 80 C, or greater than 90 C.
[0082] As another illustrative, non-exclusive example, the supplying at 220 and/or the combusting at 225 may be initiated based, at least in part, on a property of the heated and diluted hydrocarbons, illustrative, non-exclusive examples of which include a temperature of the heated and diluted hydrocarbons and/or a viscosity of the heated and diluted hydrocarbons. It is within the scope of the present disclosure that the property of the heated and diluted hydrocarbons may be measured at any suitable location, illustrative, non-exclusive examples of which include within the subterranean formation, within the wellbore, and/or within the surface region.
[0083] As an illustrative, non-exclusive example, the supplying at 220 and/or the combusting at 225 may be initiated to maintain the temperature of the heated and diluted hydrocarbons above a threshold lower hydrocarbon temperature, illustrative, non-exclusive examples of which include temperatures of greater than 15 C, greater than 20 C, greater than 25 C, greater than 30 C, greater than 35 C, greater than 40 C, greater than 50 C, greater than 60 C, greater than 70 C, greater than 80 C, or greater than 90 C. As another illustrative, non-exclusive example, the supplying at 220 and/or the combusting at 225 may be initiated to maintain the viscosity of the heated and diluted hydrocarbons below a threshold viscosity, illustrative, non-exclusive examples of which include viscosities of less than 5000 cP, less than 4500 cP, less than 4000 cP, less than 3500 cP, less than 3000 cP, less than 2500 cP, less than 2000 cP, less than 1500 cP, or less than 1000 cP.
[0084] Ceasing the supplying of the oxidant while continuing the supplying of the dual-duty agent at 230 may include selectively blocking, stopping, and/or occluding the supplying at 220 while permitting and/or continuing the supplying at 215. It is within the scope of the present disclosure that the ceasing at 230 also may include and/or be referred to as ceasing the combusting, since ceasing the supply of oxidant to the subterranean formation will starve the combustion reaction for oxidant, thereby ceasing, or initiating a cease in, the combustion reaction that is occurring therein.
[0085] It is within the scope of the present disclosure that the ceasing may include ceasing based upon any suitable criteria and/or combination of criteria. As an illustrative, non-exclusive example, the ceasing at 230 may be based, at least in part, on an elapsed time since the start of the supplying at 220.
[0086] As another illustrative, non-exclusive example, the ceasing at 230 may be based, at least in part, on the temperature of the heated zone. Thus, the ceasing at 230 may include ceasing the supplying of oxidant to the subterranean formation to maintain the temperature of the heated zone below a threshold upper heated zone temperature, illustrative, non-exclusive examples of which include temperatures of less than 900 C, less than 850 C, less than 825 C, less than 800 C, less than 775 C, less than 750 C, less than 725 C, less than 700 C, less than 675 C, less than 650 C, less than 600 C, less than 550 C, or less than 500 C.
2012E1\4246-CA
[0087] As yet another illustrative, non-exclusive example, the ceasing at 230 may be based, at least in part, on a property of the heated and diluted hydrocarbons, illustrative, non-exclusive examples of which are discussed in more detail herein with reference to the supplying at 220. As an illustrative, non-exclusive example, the ceasing at 230 may include .. ceasing the supply of oxidant to the subterranean formation to maintain the temperature of the heated and diluted hydrocarbons below a threshold upper hydrocarbon temperature, illustrative, non-exclusive examples of which include temperatures of less than 500 C, less than 450 C, less than 400 C, less than 375 C, less than 350 C, less than 325 C, less than 300 C, less than 250 C, or less than 200 C. As another illustrative, non-exclusive example, the supplying the dual-duty agent to the subterranean formation at 215 may include supplying a predetermined volume of the dual-duty agent to the subterranean formation, and the ceasing at 230 may be based, at least in part, on combustion of a fraction of the predetermined volume of the dual-duty agent. As illustrative, non-exclusive examples, the ceasing at 230 may be responsive to combustion of at least 0.5 volume %, at least 1 volume %, at least 2 volume %, at least 3 volume (Vo, at least 4 volume %, at least 5 volume %, at least 6 volume %, at least 7 volume %, at least 8 volume %, at least 9 volume %, at least 10 volume %, or at least 15 volume %, of the predetermined volume of the dual-duty agent.
Additionally or alternatively, the ceasing at 230 may include ceasing such that less than 30 volume %, less than 25 volume %, less than 22.5 volume %, less than 20 volume %, less than 17.5 volume A, less than 15 volume %. less than 12.5 volume %, less than 10 volume %, less than 7.5 volume %, or less than 5 volume % of the predetermined volume of the dual-duty agent is combusted in the subterranean formation.
[0088] Flowing the uncombusted portion of the dual-duty agent through the heated zone to generate the heated dual-duty agent at 235 may include heating the uncombusted portion of the dual-duty agent within the heated zone. As an illustrative, non-exclusive example, the flowing may include thermally contacting the uncombusted portion of the dual-duty agent with the heated zone and/or with reservoir solids, such as sand and/or rock, that may be present within the heated zone. As another illustrative, non-exclusive example, the flowing may include transferring thermal energy from the heated zone to the dual-duty agent to generate the heated dual-duty agent. As discussed, the uncombusted portion of the dual-duty agent also may be referred to herein as a second portion of the dual-duty agent and/or a portion of the dual-duty agent that is not combusted within the heated zone.
[0089] Contacting the viscous hydrocarbons with the heated dual-duty agent to generate the heated and diluted hydrocarbons at 240 may include thermally and/or physically contacting the heated dual-duty agent with the viscous hydrocarbons.
Additionally or alternatively, the contacting at 240 also may include absorbing the heated dual-duty agent within the viscous hydrocarbons, mixing the heated dual-duty agent with the viscous hydrocarbons, and/or diluting the viscous hydrocarbons with the heated dual-duty agent. As discussed, the concurrent heating and diluting of the viscous hydrocarbons through combination with the heated and diluted dual-duty agent may significantly decrease a viscosity thereof and/or generate heated and diluted hydrocarbons with a viscosity that is significantly lower than that of the viscous hydrocarbons.
[0090] As discussed, generating the heated and diluted hydrocarbons through the contacting at 240 using the systems and methods that are disclosed herein may include generating the heated and diluted hydrocarbons without generating two separate liquid hydrocarbon phases that include the viscous hydrocarbon within the subterranean formation.
Additionally or alternatively, generating the heated and diluted hydrocarbons through the contacting at 240 may significantly decrease a volume of the heavy liquid hydrocarbon phase when compared to methods that include contacting the viscous hydrocarbons with an unheated diluent.
[0091] As illustrative, non-exclusive examples, the contacting at 240 may include generating both the heavy liquid hydrocarbon phase and the light liquid hydrocarbon phase;
however, when both phases are generated, the volume of the heavy liquid hydrocarbon phase may comprise less than 25%, less than 20%, less than 15%, less than 10%, less than 5%, less than 2.5%, or less than 1% of the volume of the light liquid hydrocarbon phase. Thus, the producing at 245 may include producing the heated and diluted hydrocarbons from the subterranean formation without supplying a supplemental diluent to the subterranean formation to decrease the viscosity of the heavy liquid hydrocarbon phase.
[0092] Producing the heated and diluted hydrocarbons from the subterranean formation at 245 may include producing the heated and diluted hydrocarbons from a production well that extends within the subterranean formation. The producing at 245 may include producing the heated and diluted hydrocarbons from the subterranean formation without supplying steam to the subterranean formation (other than as a product of the combusting at 225) and/or without utilizing the viscous hydrocarbons that are present within the subterranean formation as a primary fuel for the combusting at 225.
[0093] As discussed in more detail herein, the production well may be separate and/or distinct from an injection well that receives the dual-duty agent and the oxidant during the supplying at 215 and 220 and that defines the heated zone. However, and as also discussed in more detail herein, it is also within the scope of the present disclosure that a single well may function as both the production well and the injection well.
[0094] When the single well functions as both the production well and the injection well, it is within the scope of the present disclosure that an auxiliary well may intersect the single well, and at least one of the dual-duty agent and the oxidant may be supplied to the production well via the auxiliary well. Additionally or alternatively, methods 200 further may include venting a combustion product stream from the production well via the auxiliary well.
[0095] Repeating the method at 250 may include repeating any suitable portion of the method. As an illustrative, non-exclusive example, the repeating at 250 may include repeating at least the supplying at 215, the supplying at 220, and the combusting at 225 subsequent to the ceasing at 230, the flowing at 235, and the contacting at 240 to further heat and dilute the viscous hydrocarbons that may be present within the subterranean formation.
[0096] Fig. 6 is a flowchart depicting methods 300 according to the present disclosure of enhancing production of viscous hydrocarbons from a subterranean formation.
Methods 300 may include performing an initial production-enhancing process at 305 and include converting the viscous hydrocarbons to heated and diluted hydrocarbons at 310.
Methods 300 further may include performing a subsequent production-enhancing process at 315 and include producing the heated and diluted hydrocarbons from the subterranean formation at 320. Methods 300 additionally may include repeating the methods at 325.
[0097] It is within the scope of the present disclosure that the converting at 310 may form a portion of a subsequent production-enhancing process that is configured to be performed within the subterranean formation after performing an initial production-enhancing process.
Under these conditions, performing the initial production-enhancing process at 305 may include performing any suitable process and/or operation within the subterranean formation to decrease the viscosity of the viscous hydrocarbons that are contained therein and/or to produce the viscous hydrocarbons therefrom.
[0098] As illustrative, non-exclusive examples, and as discussed, the initial production-enhancing processes may include one or more of in situ combustion, a cyclic solvent process, cyclic steam injection, steam assisted gravity drainage, solvent assisted gravity drainage, solvent assisted steam assisted gravity drainage, steatnflood, heated solvent, non-heated vapor extraction, and/or heated vapor extraction. It is within the scope of the present disclosure that performing the initial production-enhancing process at 305 may include removing and/or depleting the viscous hydrocarbons from a region, or portion, of the subterranean formation, such as from a heated zone that may be utilized during the converting at 310.
[0099] It is also within the scope of the present disclosure that methods 300 further may include depressurizing, or blowing down, the subterranean formation and/or an injection well that extends therein. As an illustrative, non-exclusive example, the depressurizing may include depressurizing the injection well after performing the initial production-enhancing process and prior to performing the subsequent production-enhancing process.
As another illustrative, non-exclusive example, the depressurizing may include depressurizing the injection well subsequent to performing both the initial production-enhancing process and the subsequent production-enhancing process.
[0100] Converting the viscous hydrocarbons to heated and diluted hydrocarbons at 310 may include performing any suitable production-enhancing process to both heat and dilute the viscous hydrocarbons that are present within the subterranean formation.
As an illustrative, non-exclusive example, the converting at 310 may include performing any of the methods 200 that are disclosed herein and discussed in more detail with reference to Fig. 5.
[0101] It is within the scope of the present disclosure that the converting at 310 may form a portion of an initial production-enhancing process that is configured to be performed within the subterranean formation prior to performing a subsequent production-enhancing process.
Under these conditions, performing the subsequent production-enhancing process at 315 may include performing any suitable process and/or operation within the subterranean formation to decrease the viscosity of the viscous hydrocarbons that are contained therein and/or to produce the viscous hydrocarbons therefrom. Illustrative, non-exclusive examples of subsequent production-enhancing processes include any of the initial production-enhancing processes that are discussed in more detail herein with reference to performing the initial production-enhancing process at 305.
[0102] Producing the heated and diluted hydrocarbons from the subterranean formation at 320 may include the use of any suitable systems and/or methods to remove the heated and diluted hydrocarbons from the subterranean formation and/or to convey the heated and diluted hydrocarbons to a surface region, and may be at least substantially similar to the producing at 245 that is discussed in more detail herein with reference to Fig. 5. It is within the scope of the present disclosure that the producing at 320 may be intermittent or continuous. As an illustrative, non-exclusive example, and when a single wellbore is utilized during the converting at 310 (such as for supply of the dual-duty agent and the oxidant to the subterranean formation) and the producing at 320 (such as to convey the heated and diluted hydrocarbons from the subterranean formation and to the surface region), the producing at 320 may be performed intermittently and/or subsequent to the converting at 310. As another illustrative, non-exclusive example, and when an injection well is utilized during the converting at 310 (such as for supply of the dual-duty agent and the oxidant to the subterranean formation) and a separate production well is utilized during the producing at 320 (such as to convey the heated and diluted hydrocarbons from the subterranean formation and to the surface region), the producing at 320 may be performed continuously, at least substantially continuously, and/or during the converting at 310.
[0103] It is also within the scope of the present disclosure that the producing at 320 may be performed any suitable number of times and/or in any suitable sequence during methods 300. As an illustrative, non-exclusive example, and when methods 300 include both the performing at 305 and the converting at 310, the producing at 320 may be performed both subsequent to the performing at 305 and subsequent to the converting at 310.
Alternatively, the producing at 320 may be performed subsequent to the converting at 310 but not subsequent to the performing at 305. As another illustrative, non-exclusive example, and when methods 300 include the converting at 310 and the performing at 315, the producing at 320 may be performed both subsequent to the converting at 310 and subsequent to the performing at 315. Alternatively, the producing at 320 may be performed subsequent to the performing at 315 but not subsequent to the converting at 310.
[0104] Repeating the method at 325 may include repeating any suitable portion of the method based on any suitable criteria. As an illustrative, non-exclusive example, and when methods 300 include the performing at 305, the repeating at 325 may include repeating the performing at 305 a plurality of times prior to the converting at 310; and an illustrative, non-exclusive example of this repeating is discussed in more detail herein with reference to Fig. 4.
Additionally or alternatively, the repeating at 325 also may include repeating the converting at 310 a plurality of times subsequent to the performing at 305 and/or repeating the performing at 305 one or more times subsequent to the converting at 310.
[0105] Alternatively, and when methods 300 include the performing at 315, the repeating at 325 also may include repeating the converting at 310 a plurality of times prior to the performing at 315 and/or repeating the performing at 315 a plurality of times subsequent to the converting at 310. Additionally or alternatively, the repeating at 325 also may include repeating the converting at 310 one or more times subsequent to the performing at 315.
[0106] As discussed, the producing at 320 may be performed any suitable number of times and/or in any suitable sequence during methods 300. Thus, the repeating at 325 further may include repeating the producing at 320, such as by performing the producing subsequent to the performing at 305, subsequent to the converting at 310, and/or subsequent to the performing at 315.
[0107] In the present disclosure, several of the illustrative, non-exclusive examples have been discussed and/or presented in the context of flow diagrams, or flow charts, in which the methods are shown and described as a series of blocks, or steps. Unless specifically set forth in the accompanying description, it is within the scope of the present disclosure that the order of the blocks may vary from the illustrated order in the flow diagram, including with two or more of the blocks (or steps) occurring in a different order and/or concurrently. It is also within the scope of the present disclosure that the blocks, or steps, may be implemented as logic, which also may be described as implementing the blocks, or steps, as logics. In some applications, the blocks, or steps, may represent expressions and/or actions to be performed by functionally equivalent circuits or other logic devices. The illustrated blocks may, but are not required to, represent executable instructions that cause a computer, processor, and/or other logic device to respond, to perform an action, to change states, to generate an output or display, and/or to make decisions.
[0108] As used herein, the term "and/or placed between a first entity and a second entity means one of (1) the first entity, (2) the second entity, and (3) the first entity and the second entity. Multiple entities listed with "and/or should be construed in the same manner, i.e., "one or more" of the entities so conjoined. Other entities may optionally be present other than the entities specifically identified by the "and/or" clause, whether related or unrelated to those entities specifically identified. Thus, as a non-limiting example, a reference to "A
and/or B," when used in conjunction with open-ended language such as "comprising" may refer, in one embodiment, to A only (optionally including entities other than B); in another embodiment, to B only (optionally including entities other than A); in yet another embodiment, to both A and B (optionally including other entities). These entities may refer to elements, actions, structures, steps, operations, values, and the like.
[0109] As used herein, the phrase "at least one," in reference to a list of one or more entities should be understood to mean at least one entity selected from any one or more of the entity in the list of entities, but not necessarily including at least one of each and every entity specifically listed within the list of entities and not excluding any combinations of entities in the list of entities. This definition also allows that entities may optionally be present other than the entities specifically identified within the list of entities to which the phrase "at least one" refers, whether related or unrelated to those entities specifically identified. Thus, as a non-limiting example, "at least one of A and B" (or, equivalently, "at least one of A or B," or, equivalently "at least one of A and/or B") may refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including entities other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including entities other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other entities). In other words, the phrases "at least one," "one or more," and "and/or" are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions "at least one of A, B and C," "at least one of A, B, or C," "one or more of A, B, and C," "one or more of A, B, or C" and "A, B, and/or C" may mean A alone, B alone, C
alone, A and B
together, A and C together, B and C together, A, B and C together, and optionally any of the above in combination with at least one other entity.
[0110]
[0111] As used herein the terms "adapted" and "configured" mean that the element, component, or other subject matter is designed and/or intended to perform a given function.
Thus, the use of the terms "adapted" and "configured" should not be construed to mean that a given element, component, or other subject matter is simply "capable of"
performing a given function but that the element, component, and/or other subject matter is specifically selected, created, implemented, utilized, programmed, and/or designed for the purpose of performing the function. It is also within the scope of the present disclosure that elements, components, and/or other recited subject matter that is recited as being adapted to perform a particular function may additionally or alternatively be described as being configured to perform that function, and vice versa.
[0112]
Illustrative, non-exclusive examples of systems and methods according to the present disclosure are presented in the following enumerated paragraphs. It is within the scope of the present disclosure that an individual step of a method recited herein, including in the following enumerated paragraphs, may additionally or alternatively be referred to as a "step for" performing the recited action.
[0113] Al. A
method of heating and diluting viscous hydrocarbons within a subterranean formation, the method comprising:
supplying a dual-duty agent to the subterranean formation;
supplying an oxidant to the subterranean formation;
combusting a combusted portion of the dual-duty agent with the oxidant to heat a portion of the subterranean formation, with this portion of the subterranean formation forming a heated zone of the subterranean formation;
ceasing the supplying of the oxidant while continuing the supplying of the dual-duty agent to the subterranean formation;
flowing an uncombusted portion of the dual-duty agent through the heated zone to heat the uncombusted portion of the dual-duty agent and generate a heated dual-duty agent;
and contacting the viscous hydrocarbons with the heated dual-duty agent to generate heated and diluted hydrocarbons.
[0114] A2. The method of paragraph Al, wherein the supplying the dual-duty agent includes continuously supplying the dual-duty agent.
[0115] A3. The method of paragraph Al, wherein the supplying the dual-duty agent includes periodically supplying the dual-duty agent.
[0116] A4. The method of any of paragraphs Al-A3, wherein the supplying the oxidant includes periodically supplying the oxidant.
[0117] Bl. A method of heating and diluting viscous hydrocarbons within a subterranean formation, the method comprising:
continuously supplying a dual-duty agent to the subterranean formation;
periodically supplying an oxidant to the subterranean formation;
combusting a combusted portion with the oxidant of the dual-duty agent in a heated zone of the subterranean formation during the periodically supplying;
flowing an uncombusted portion of the dual-duty agent through the heated zone to heat the uncombusted portion of the dual-duty agent and generate a heated dual-duty agent;
and contacting the viscous hydrocarbons with the heated dual-duty agent to generate heated and diluted hydrocarbons.
[0118] B2. The method of paragraph Bl, wherein the periodically supplying the oxidant includes ceasing the supplying of the oxidant while continuing the supplying of the dual-duty agent to the subterranean formation.
[0119] Cl. The method of any of paragraphs A 1 -B2, wherein, prior to supplying the dual-duty agent, the method further includes pre-heating the dual-duty agent.
[0120] C2. The method of paragraph Cl, wherein the pre-heating includes pre-heating the dual-duty agent within a surface region, and optionally wherein the surface region is proximate to a wellbore that extends within the subterranean formation.
[0121] C3. The method of any of paragraphs Al -C2, wherein the method further includes producing the heated and diluted hydrocarbons from the subterranean formation.
[0122] C4. The method of paragraph C3, wherein the producing includes producing from a production well that extends within the subterranean formation.
[0123] C5. The method of any of paragraphs C3-C4, wherein the combusting includes producing a gaseous combustion product and pressurizing the subterranean formation with the gaseous combustion product to provide a motive force for the producing.
[0124] C6. The method of any of paragraphs C3-05, wherein the producing further includes producing the heated and diluted hydrocarbons from the subterranean formation without supplying a supplemental dual-duty agent to the subterranean formation.
[0125] C7. The method of any of paragraphs C4-C6, wherein the (continuously) supplying the dual-duty agent and the (periodically) supplying the oxidant include supplying the dual-duty agent and the oxidant to the production well.
[0126] C8. The method of paragraph C7, wherein at least one of the (continuously) supplying the dual-duty agent and the (periodically) supplying the oxidant includes supplying the at least one of the dual-duty agent and the oxidant to the production well via an auxiliary well that intersects the production well, and optionally wherein the method further includes venting a combustion product stream from the production well via the auxiliary well.
[0127] C9. The method of any of paragraphs C4-C6, wherein the (continuously) supplying the dual-duty agent and the (periodically) supplying the oxidant includes supplying the dual-duty agent and the oxidant to an injection well that is separate from the production well.
[0128] C I O. The method of paragraph C9, wherein the combusting includes at least one of combusting within the simulation well and combusting within a portion of the subterranean formation that is adjacent to the injection well.
[0129] Cl 1 . The method of any of paragraphs C9-C10, wherein the injection well is at least one of adjacent to at least a portion of the production well, parallel to at least a portion .. of the production well, and located vertically above at least a portion of the production well.
[0130] C12. The method of any of paragraphs Al-C1 1, wherein the (continuously) supplying the dual-duty agent, the (periodically) supplying the oxidant, and the combusting include supplying the dual-duty agent and the oxidant to a/the wellbore that extends within the subterranean formation and combusting a combustible mixture that includes the dual-duty agent and the oxidant.
[0131] C13. The method of paragraph C12, wherein the combusting includes combusting within the wellbore.
[0132] C14. The method of any of paragraphs C12-C13, wherein the combusting includes combusting within a portion of the subterranean formation that is proximal to the wellbore.
[0133] C15. The method of paragraph C14, wherein a majority of the viscous hydrocarbons are removed from the portion of the subterranean formation prior to the combusting, and optionally wherein the method further includes removing the majority of the viscous hydrocarbons from the portion of the subterranean formation prior to the combusting.
[0134] C16. The method of any of paragraphs A 1 -C 15, wherein the (continuously) supplying the dual-duty agent includes supplying the dual-duty agent to the subterranean formation as a liquid dual-duty agent, and optionally wherein the method further includes vaporizing the dual-duty agent within the subterranean formation to generate a vaporous dual-duty agent.
[0135] C17. The method of any of paragraphs A1-C16, wherein the (continuously) supplying the dual-duty agent includes supplying the dual-duty agent to the subterranean formation as at least one of a gas and a vapor.
[0136] C18. The method of any of paragraphs AI-C17, wherein the method further includes mixing the oxidant with the dual-duty agent within at least one of a/the wellbore, the subterranean formation, and the heated zone to form a/the combustible mixture.
[0137] C19. The method of paragraph C18, wherein the method further includes igniting the combustible mixture within the heated zone, optionally wherein the igniting includes actuating an ignition source that is present within the heated zone.
[0138] C20. The method of any of paragraphs A 1 -C19, wherein the (periodically) supplying the oxidant and the combusting are initiated based, at least in part, on an elapsed time since a prior (periodically) supplying the oxidant.
[0139] C21. The method of any of paragraphs Al-C20, wherein the (periodically) supplying the oxidant and the combusting arc initiated based, at least in part, on a temperature of the heated zone, optionally wherein the (periodically) supplying and the combusting are initiated to maintain the temperature of the heated zone above a threshold lower heated zone temperature, and further optionally wherein the threshold lower heated zone temperature is greater than 15 C, greater than 20 C, greater than 25 C, greater than 30 C, greater than 35 C, greater than 40 C, greater than 50 C, greater than 60 C, greater than 70 C, greater than 80 C, or greater than 90 C.
[0140] C22. The method of any of paragraphs A 1-C21, wherein the (periodically) supplying the oxidant and the combusting are initiated based, at least in part, on a property of the heated and diluted hydrocarbons.
[0141] C23. The method of paragraph C22, wherein the property of the heated and diluted hydrocarbons includes a temperature of the heated and diluted hydrocarbons, optionally wherein the temperature of the heated and diluted hydrocarbons is measured within the subterranean formation, optionally wherein the temperature of the heated and diluted hydrocarbons is measured within a/the surface region, optionally wherein the (periodically) supplying and the combusting are initiated to maintain the temperature of the heated and diluted hydrocarbons above a threshold lower hydrocarbon temperature, and further optionally wherein the threshold lower hydrocarbon temperature is greater than 15 C, greater than 20 C, greater than 25 C, greater than 30 C, greater than 35 C, greater than 40 C, greater than 50 C, greater than 60 C, greater than 70 C, greater than 80 C, or greater than 90 C.
[0142] C24. The method of any of paragraphs C22-C23, wherein the property of the heated and diluted hydrocarbons includes a viscosity of the heated and diluted hydrocarbons, optionally wherein the viscosity of the heated and diluted hydrocarbons is measured within the subterranean formation, optionally wherein the viscosity of the heated and diluted hydrocarbons is measured in a/the surface region, optionally wherein the (periodically) supplying and the combusting are initiated to maintain the viscosity of the heated and diluted hydrocarbons below a threshold viscosity, and further optionally wherein the threshold viscosity is less than 5000 cP, less than 4500 cP, less than 4000 cP, less than 3500 cP, less than 3000 cP, less than 2500 cP, less than 2000 cP, less than 1500 cP, or less than 1000 cP.
[0143] C25. The method of any of paragraphs A1-C24, wherein the combusting includes combusting a fuel stream that includes the combusted portion of the dual-duty agent and a portion of the viscous hydrocarbons.
[0144] C26. The method of paragraph C25, wherein the dual-duty agent comprises at least 60 wt%, at least 65 wt%, at least 70 wt%, at least 75 wt%, at least 80 wt%, at least 85 wt%, at least 90 wt%, at least 95 wt%, at least 96 wt%, at least 97 wt%, at least 98 wt%, or at least 99 wt% of the fuel stream.
[0145] C27. The method of any of paragraphs C25-C26, wherein the viscous hydrocarbons comprise less than 40 wt%, less than 35 wt%, less than 30 wt%, less than 25 wt%, less than 20 wt%, less than 15 wt%, less than 10 wt%, less than 5 wt%, less than 4 wt%, less than 3 wt%. less than 2 wt%, or less than 1 wt% of the fuel stream.
[0146] C28. The method of any of paragraphs A1-C27, wherein a/the ceasing the supplying of the oxidant includes at least one of ceasing the combusting and initiating ceasing of the combusting.
[0147] C29. The method of any of paragraphs Al-C28, wherein a/the ceasing the supplying of the oxidant includes ceasing the supplying of the oxidant based, at least in part, on an elapsed time since a start of the (periodically) supplying the oxidant.
[0148] C30. The method of any of paragraphs A 1 -C29, wherein a/the ceasing the supplying of the oxidant includes ceasing the supplying of the oxidant based, at least in part, on a/the temperature of the heated zone, optionally wherein the ceasing the supplying includes ceasing the supplying to maintain the temperature of the heated zone below a threshold upper heated zone temperature, and further optionally wherein the threshold upper heated zone temperature includes a temperature of less than 900 C, less than 850 C, less than 825 C, less than 800 C, less than 775 C, less than 750 C, less than 725 C, less than 700 C, less than 675 C, less than 650 C, less than 600 C, less than 550 C, or less than 500 C.
[0149] C31. The method of any of paragraphs AI -C30, wherein a/the ceasing the supplying of the oxidant includes ceasing the supplying of the oxidant based, at least in part, on a/the property of the heated and diluted hydrocarbons.
[0150] C32. The method of paragraph C31, wherein the property of the heated and diluted hydrocarbons includes a/the temperature of the heated and diluted hydrocarbons, optionally wherein the temperature of the heated and diluted hydrocarbons is measured within the subterranean formation, optionally wherein the temperature of the heated and diluted hydrocarbons is measured within a/the surface region, optionally wherein the ceasing the supplying of the oxidant includes ceasing the supplying of the oxidant to maintain the temperature of the heated and diluted hydrocarbons below a threshold upper hydrocarbon temperature, and further optionally wherein the threshold upper hydrocarbon temperature is less than 500 C, less than 450 C, less than 400 C, less than 375 C, less than 350 C, less than 325 C, less than 300 C, less than 250 C, or less than 200 C.
[0151] C33. The method of any of paragraphs Al-C32, wherein the (continuously) supplying the dual-duty agent to the subterranean formation includes supplying a predetermined volume of the dual-duty agent to the subterranean formation.
[0152] C34. The method of paragraph C33, wherein a/the ceasing the supplying of the oxidant includes ceasing the supplying of the oxidant responsive to combusting a fraction of the predetermined volume of the dual-duty agent, optionally wherein the fraction is at least 0.5 volume %, at least 1 volume %, at least 2 volume %, at least 3 volume %, at least 4 volume %, at least 5 volume %, at least 6 volume %, at least 7 volume %, at least 8 volume %, at least 9 volume %, at least 10 volume %, or at least 15 volume % of the predetermined volume of the dual-duty agent, and further optionally wherein the fraction is less than 30 volume %, less than 25 volume %, less than 22.5 volume %. less than 20 volume %, less than 17.5 volume %, less than 15 volume %, less than 12.5 volume %, less than 10 volume %, less than 7.5 volume %, or less than 5 volume % of the predetermined volume of the dual-duty agent.
[0153] C35. The method of any of paragraphs Al -C34, wherein the flowing the uncombusted portion of the dual-duty agent through the heated zone includes thermally contacting the uncombusted portion of the dual-duty agent with the heated zone, and optionally with reservoir solids that are present within the heated zone.
[0154] C36. The method of any of paragraphs Al-C35. wherein the flowing the uncombusted portion of the dual-duty agent through the heated zone includes transferring thermal energy from the heated zone, and optionally from a/the reservoir solids that are present within the heated zone, to the dual-duty agent to generate the heated dual-duty agent.
[0155] C37. The method of any of paragraphs A 1 -C36, wherein the contacting the viscous hydrocarbons with the heated dual-duty agent includes at least one, and optionally both, of thermally contacting the viscous hydrocarbons with the heated dual-duty agent and physically contacting the viscous hydrocarbons with the heated dual-duty agent.
[0156] C38. The method of any of paragraphs Al-C37, wherein the contacting the viscous hydrocarbons with the heated dual-duty agent includes at least one of absorbing the heated dual-duty agent within the viscous hydrocarbons and mixing the heated dual-duty agent with the viscous hydrocarbons.
[0157] C39. The method of any of paragraphs Al-C38, wherein the contacting the viscous hydrocarbons with the heated dual-duty agent includes at least one of diluting the viscous hydrocarbons with the heated dual-duty agent and forming a mixture of the heated dual-duty agent and the viscous hydrocarbons.
[0158] C40. The method of any of paragraphs A 1-C39, wherein the method further includes generating the heated and diluted hydrocarbons without generating two separate liquid hydrocarbon phases that include the viscous hydrocarbons within the subterranean formation.
[0159] C41. The method of any of paragraphs AI-C39, wherein the method further includes generating a heavy liquid hydrocarbon phase that includes a portion of the viscous hydrocarbons and a light liquid hydrocarbon phase that includes a portion of the viscous hydrocarbons within the subterranean formation, and further wherein a volume of the generated heavy liquid hydrocarbon phase is less than 25%, less than 20%, less than 15%, less than 10%, less than 5%, less than 2.5%, or less than 1% of a volume of the generated light liquid hydrocarbon phase.
[0160] C42. The method of any of paragraphs A1-C41, wherein the combusting includes generating a/the gaseous combustion product, and further wherein the method includes retaining the gaseous combustion product within the subterranean formation.
[0161] C43. The method of any of paragraphs Al -C42, wherein the method further includes producing the heated and diluted hydrocarbons without supplying a/the supplemental diluent to the subterranean formation.
[0162] C44. The method of any of paragraphs Al -C43, wherein the method further includes producing the heated and diluted hydrocarbons without supplying steam to the subterranean formation.
[0163] C45. The method of any of paragraphs Al -C44, wherein the method further includes producing the heated and diluted hydrocarbons without utilizing the viscous hydrocarbons as a primary fuel for the combusting.
[0164] C46. The method of any of paragraphs A1-C45, wherein the dual-duty agent includes a flammable material.
[0165] C47. The method of any of paragraphs Al -C46, wherein the dual-duty agent includes a material that at least one of dilutes the viscous hydrocarbons, is soluble in the viscous hydrocarbons, dissolves the viscous hydrocarbons, decreases a/the viscosity of the viscous hydrocarbons, and is miscible in the viscous hydrocarbons.
[0166] C48. The method of any of paragraphs Al -C47, wherein the dual-duty agent includes at least one of a diluent and a solvent for at least a portion of the viscous hydrocarbons.
[0167] C49.
The method of any of paragraphs AI -C48, wherein the dual-duty agent includes at least one of methane, ethane, propane, butane, pentane, hexane, heptane, octane, nonane, decane, dimethyl ether, an alkane, naphtha, natural gas condensate, gas plant condensate, and mixtures of the above.
[0168] C50. The method of any of paragraphs Al-C49, wherein the viscous hydrocarbons include at least one of bitumen, tar, an unconventional hydrocarbon reserve, and a hydrocarbon with a viscosity that is too high to be produced from the subterranean formation using primary hydrocarbon recovery operations and secondary hydrocarbon recovery operations.
[0169] C51. The method of any of paragraphs Al-050, wherein the subterranean formation includes at least one of an oil sands formation, a tar sands formation, and a bituminous sands formation.
[0170] C52.
The method of any of paragraphs Al-051, wherein the oxidant includes at least one of oxygen, air, oxygen-enriched air, and a chemical oxidant.
[0171] C53. The method of any of paragraphs Al-052, wherein the heated and diluted hydrocarbons have a temperature that is at least one of:
(i) greater than an ambient temperature within the subterranean formation prior to the combusting;
(ii) greater than a temperature of the viscous hydrocarbons prior to the contacting;
and (iii) at least 15 C, at least 20 C, at least 25 C, at least 30 C, at least 35 C, at least 40 C, at least 45 C, at least 50 C, at least 55 C, at least 60 C, at least 65 C, at least 70 C, at least 75 C, at least 80 C, at least 85 C, at least 90 C, at least 95 C, or at least 100 C.
[0172] C54. The method of any of paragraphs Al-053, wherein the heated and diluted hydrocarbons have a viscosity that is at least 2, at least 3, at least 4, at least 5, at least 10, at least 25, at least 50, at least 100, at least 250, at least 500, at least 750, or at least 1000 times lower than at least one of:
(i) an average viscosity of the viscous hydrocarbons prior to the combusting; and (ii) an average viscosity of the viscous hydrocarbons prior to the contacting.
[0173] C55. The method of any of paragraphs A 1 -054, wherein the heated and diluted hydrocarbons include a mixture of the viscous hydrocarbons and the uncombusted portion of the dual-duty agent, and optionally wherein the heated and diluted hydrocarbons further include gaseous combustion products from the combusting.
[0174] C56. The method of any of paragraphs Al-055, wherein the heated zone includes a portion of a/the wellbore that extends within the subterranean formation.
[0175] C57. The method of any of paragraphs A1-056. wherein the heated zone includes a portion of the subterranean formation where the combusting occurs.
[0176] C58. The method of any of paragraphs A1-057, wherein the heated zone includes reservoir solids that are heated by the combusting.
[0177] C59. The method of any of paragraphs A1-058, wherein the method further includes repeating the method, optionally wherein the repeating includes repeating at least the (periodically) supplying the oxidant and the combusting subsequent to the flowing and the contacting.
[0178] Dl. A method of enhancing production of viscous hydrocarbons from a subterranean formation, the method comprising:
converting the viscous hydrocarbons to heated and diluted hydrocarbons using the method of any of paragraphs Al-059; and producing the heated and diluted hydrocarbons from the subterranean formation.
[0179] D2. The method of paragraph Dl, wherein, subsequent to the converting, the method further includes performing a cyclic solvent process to produce a portion of the viscous hydrocarbons from the subterranean formation.
[0180] D3. The method of paragraph D2, wherein the method further includes repeating the cyclic solvent process a plurality of times subsequent to the converting.
[0181] D4. The method of paragraph D1, wherein the converting forms a portion of an initial production-enhancing process, and further wherein, subsequent to the converting, the method further includes performing a subsequent production-enhancing process.
[0182] D5. The method of paragraph D4, wherein the subsequent production-enhancing process includes a cyclic solvent process.
[0183] D6. The method of paragraph D4, wherein the subsequent production-enhancing process includes at least one of in situ combustion, a cyclic solvent process, cyclic steam stimulation, steam assisted gravity drainage, solvent assisted steam assisted gravity drainage, solvent assisted gravity drainage, steamflood, heated solvent, non-heated vapor extraction, and heated vapor extraction.
[0184] D7. The method of any one of paragraphs D1-D6, wherein the converting forms a portion of a subsequent production-enhancing process, and further wherein, prior to the converting, the method further includes performing an initial production-enhancing process, and optionally wherein the method further includes depressurizing a/the injection well that extends within the subterranean formation after performing the initial production-enhancing process and prior to performing the subsequent production-enhancing process.
[0185] D8. The method of paragraph D7, wherein the initial production-enhancing process includes a cyclic solvent process.
[0186] D9. The method of paragraph D7, wherein the initial production-enhancing process includes at least one of in situ combustion, a cyclic solvent process, cyclic steam stimulation, steam assisted gravity drainage, solvent assisted steam assisted gravity drainage, solvent assisted gravity drainage, steamflood, heated solvent, non-heated vapor extraction, and heated vapor extraction.
[0187] D10. The method of any of paragraphs D4-D9, wherein the method further includes repeating the initial production-enhancing process a plurality of times prior to performing the subsequent production-enhancing process.
[0188] D11. The method of any of paragraphs D4-D10, wherein the method further includes repeating the subsequent production-enhancing process a plurality of times subsequent to performing the initial production-enhancing process.
[0189] D12. The method of any of paragraphs D4-D11, wherein the method further includes repeating the initial production-enhancing process subsequent to performing the subsequent production-enhancing process, and optionally wherein the method further includes repeating the subsequent production-enhancing process subsequent to repeating the initial production-enhancing process.
[0190] D13. The method of any of paragraphs D4-D12, wherein the method further includes repeating the initial production-enhancing process a plurality of times.
[0191] D14. The method of any of paragraphs D4-D13, wherein the method further includes repeating the subsequent production-enhancing process a plurality of times.
[0192] D15. The method of any of paragraphs DJ-D14, wherein the method includes ceasing the converting during the producing.
[0193] D16. The method of paragraph D15, wherein the converting includes conveying the dual-duty agent through a/the wellbore that extends within the subterranean formation, and further wherein the producing includes producing the heated and diluted hydrocarbons from the wellbore.
[0194] D17. The method of any of paragraphs DI-D14, wherein the method includes continuing the converting during the producing.
[0195] D18. The method of paragraph D17, wherein the converting includes conveying the dual-duty agent through a/the injection well that extends within the subterranean formation, and further wherein the producing includes producing the heated and diluted hydrocarbons from a production well that is separate from the injection well.
[0196] D19. The method of any of paragraphs D1 -D18, wherein the method further includes repeating the method.
[0197] El. A viscous hydrocarbon production assembly, comprising:
a wellbore that extends between a surface region and a subterranean formation that includes a viscous hydrocarbon;
a dual-duty agent supply system that is configured to selectively supply a dual-duty agent through the wellbore to the subterranean formation;
an oxidant supply system that is configured to selectively supply an oxidant through the wellbore to the subterranean formation; and a controller that is programmed to control the operation of the viscous hydrocarbon production assembly using the method of any of paragraphs Al-D19.
[0198] E2. The viscous hydrocarbon production assembly of paragraph El, wherein the assembly further includes a heated and diluted hydrocarbon production system that is configured to produce a heated and diluted hydrocarbon stream that includes heated and diluted hydrocarbons from the subterranean formation.
[0199] E3. The viscous hydrocarbon production assembly of paragraph E2, wherein the heated and diluted hydrocarbon production system is configured to produce the heated and diluted hydrocarbon stream from the wellbore.
[0200] E4. The viscous hydrocarbon production assembly of paragraph E2, wherein the wellbore forms a portion of an injection well, wherein the assembly further includes a production well that extends between the surface region and the subterranean formation, and further wherein the injection well is separate from the production well.
[0201] E5. The viscous hydrocarbon production assembly of paragraph E4, wherein the heated and diluted hydrocarbon production system is configured to produce the heated and diluted hydrocarbon stream from the production well.
[0202] E6. The viscous hydrocarbon production assembly of any of paragraphs E4-E5, wherein at least a parallel portion of the injection well is parallel to at least a parallel portion of the production well.
[0203] E7. The viscous hydrocarbon production assembly of paragraph E6, wherein the parallel portion of the injection well is located vertically above the parallel portion of the production well.
[0204] E8. The viscous hydrocarbon production assembly of any of paragraphs El -E7, wherein the wellbore includes at least one of a vertical portion and a deviated portion.
[0205] E9. The viscous hydrocarbon production assembly of any of paragraphs El -E8, wherein the wellbore includes a horizontal portion, optionally wherein the horizontal portion extends within the subterranean formation.
[0206] Fl. The use of any of the methods of any of paragraphs Al-D19 with any of the assemblies of any of paragraphs E I -E9.
[0207] F2. The use of any of the assemblies of any of paragraphs El-E9 with any of the methods of any of paragraphs Al-D19.
[0208] F3. The use of any of the methods of any of paragraphs Al-A15 or any of the assemblies of any of paragraphs El -E9 to generate heated and diluted hydrocarbons.
[0209] F4. The use of any of the methods of any of paragraphs Al-Al 5 or any of the assemblies of any of paragraphs El-E9 to stimulate a subterranean formation that includes viscous hydrocarbons.
[0210] F5. The use of any of the methods of any of paragraphs Al -Al 5 or any of the assemblies of any of paragraphs El-E9 to heat and dilute viscous hydrocarbons that are present within a subterranean formation.
[0211] Fb. The use of any of the methods of any of paragraphs Al -A15 or any of the assemblies of any of paragraphs El-E9 to produce viscous hydrocarbons from a subterranean formation.
[0212] F7. The use of a dual-duty agent to heat and dilute viscous hydrocarbons that are present within a subterranean formation.
[0213] F8. The use of a dual-duty agent to stimulate production of viscous hydrocarbons from a subterranean formation.
[0214] PCT1. A method of heating and diluting viscous hydrocarbons within a subterranean formation, the method comprising:
supplying a dual-duty agent to the subterranean formation;
supplying an oxidant to the subterranean formation;
combusting a combusted portion of the dual-duty agent with the oxidant to heat a portion of the subterranean formation, with this portion of the subterranean formation .. forming a heated zone of the subterranean formation;
ceasing the supplying of the oxidant while continuing the supplying of the dual-duty agent to the subterranean formation;
flowing an uncombusted portion of the dual-duty agent through the heated zone to heat the uncombusted portion of the dual-duty agent and generate a heated dual-duty agent;
and contacting the viscous hydrocarbons with the heated dual-duty agent to generate heated and diluted hydrocarbons.
[0215] PCT2. The method of paragraph PCT1, wherein the method further includes producing the heated and diluted hydrocarbons from the subterranean formation, wherein the producing includes producing from a production well that extends within the subterranean formation, and further wherein the supplying the dual-duty agent and the supplying the oxidant include supplying the dual-duty agent and the oxidant to the production well.
[0216] PCT3. The method of paragraph PCT I, wherein the method further includes producing the heated and diluted hydrocarbons from the subterranean formation, wherein the producing includes producing from a production well that extends within the subterranean formation, and further wherein the supplying the dual-duty agent and the supplying the oxidant includes supplying the dual-duty agent and the oxidant to an injection well that is separate from the production well.
[0217] PCT4. The method of any of paragraphs PCT2-PCT3, wherein the combusting includes producing a gaseous combustion product and pressurizing the subterranean formation with the gaseous combustion product to provide a motive force for the producing.
[0218] PCT5. The method of any of paragraphs PCT1-PCT4, wherein the method further includes mixing the oxidant with the dual-duty agent within at least one of a wellbore that extends within the subterranean formation, the subterranean formation, and the heated zone to form a combustible mixture, and further wherein the method includes igniting the combustible mixture within the heated zone.
[0219] PCT6. The method of any of paragraphs PCT1-PCT5, wherein the supplying the oxidant and the combusting are initiated based, at least in part, on at least one of a temperature of the heated zone and a temperature of the heated and diluted hydrocarbons, wherein the supplying and the combusting are initiated to at least one of maintain the temperature of the heated zone above a threshold lower heated zone temperature that is greater than 25 C and maintain the temperature of the heated and diluted hydrocarbons above a threshold lower hydrocarbon temperature that is greater than 20 C.
[0220] PCT7. The method of any of paragraphs PCT1-PCT6, wherein the combusting includes combusting a fuel stream that includes the combusted portion of the dual-duty agent and a portion of the viscous hydrocarbons, wherein the dual-duty agent comprises at least 80 wt% of the fuel stream, and further wherein the viscous hydrocarbons comprise less than 20 wt% of the fuel stream.
[0221] PCT8. The method of any of paragraphs PCT1-PCT8, wherein the ceasing the supplying of the oxidant includes ceasing the supplying of the oxidant based, at least in part, on at least one of a temperature of the heated zone and a temperature of the heated and diluted hydrocarbons, and further wherein the ceasing the supplying includes ceasing the supplying to at least one of maintain the temperature of the heated zone below a threshold upper heated zone temperature that is less than 750 C and to maintain the temperature of the heated and diluted hydrocarbons below a threshold upper hydrocarbon temperature of less than 350 C.
[0222] PCT9. The method of any of paragraphs PCTI -PCT8, wherein the supplying the dual-duty agent to the subterranean formation includes supplying a predetermined volume of the dual-duty agent to the subterranean formation, and further wherein the ceasing the supplying of the oxidant includes ceasing the supplying of the oxidant responsive to combusting at least 0.5 volume % and less than 20 volume % of the predetermined volume of the dual-duty agent.
[0223] PCT10. The method of any of paragraphs PCT1-PCT9, wherein the contacting the viscous hydrocarbons with the heated dual-duty agent includes mixing the heated dual-duty agent with the viscous hydrocarbons.
[0224] PCT11. The method of any of paragraphs PCT1-PCT10, wherein the viscous hydrocarbons include at least one of bitumen, tar, an unconventional hydrocarbon reserve, and a hydrocarbon with a viscosity that is too high to be produced from the subterranean formation using primary hydrocarbon recovery operations and secondary hydrocarbon recovery operations, and further wherein the subterranean formation includes at least one of an oil sands formation, a tar sands formation, and a bituminous sands formation.
[0225] PCT12. A method of enhancing production of viscous hydrocarbons from a subterranean formation, the method comprising:
converting the viscous hydrocarbons to heated and diluted hydrocarbons using the method of any of paragraphs PCT1-PCT1 I ; and producing the heated and diluted hydrocarbons from the subterranean formation.
[0226] PCT13. A viscous hydrocarbon production assembly, comprising:
a wellbore that extends between a surface region and a subterranean formation that includes a viscous hydrocarbon;
a dual-duty agent supply system that is configured to selectively supply a dual-duty .. agent through the wellborc and to the subterranean formation;
an oxidant supply system that is configured to selectively supply an oxidant through the wellbore and to the subterranean formation; and a controller that is programmed to control the operation of the viscous hydrocarbon production assembly using the method of any of paragraphs PCT1-PCT12.
[0227] PCT 14. A method of heating and diluting viscous hydrocarbons within a subterranean formation, the method comprising:
continuously supplying a dual-duty agent to the subterranean formation;
periodically supplying an oxidant to the subterranean formation;
combusting a combusted portion of the dual-duty agent with the oxidant in a heated zone of the subterranean formation during the periodically supplying;
flowing an uncombusted portion of the dual-duty agent through the heated zone to heat the uncombusted portion of the dual-duty agent and generate a heated dual-duty agent;
and contacting the viscous hydrocarbons with the heated dual-duty agent to generate heated and diluted hydrocarbons.
[0228] PCT15. The method of paragraph PCT14, wherein the periodically supplying the oxidant includes ceasing the supplying of the oxidant while continuing the supplying of the dual-duty agent to the subterranean formation.
[0229] US1. A method of heating and diluting viscous hydrocarbons within a subterranean formation, the method comprising:
supplying a dual-duty agent to the subterranean formation;
supplying an oxidant to the subterranean formation;
combusting a combusted portion of the dual-duty agent with the oxidant to heat a portion of the subterranean formation, with this portion of the subterranean formation forming a heated zone of the subterranean formation;
ceasing the supplying of the oxidant while continuing the supplying of the dual-duty agent to the subterranean formation;
flowing an uncombusted portion of the dual-duty agent through the heated zone to heat the uncom busted portion of the dual-duty agent and generate a heated dual-duty agent;
and contacting the viscous hydrocarbons with the heated dual-duty agent to generate heated and diluted hydrocarbons.
[0230] US2. The method of paragraph US1, wherein, prior to the supplying the dual-duty agent, the method further includes pre-heating the dual-duty agent.
[0231] US3. The method of paragraph US1, wherein the method further includes producing the heated and diluted hydrocarbons from the subterranean formation.
[0232] US4. The method of paragraph US3, wherein the producing includes producing from a production well that extends within the subterranean formation, and further wherein the supplying the dual-duty agent and the supplying the oxidant include supplying the dual-duty agent and the oxidant to the production well.
[0233] US5. The method of paragraph US4, wherein at least one of the supplying the dual-duty agent and the supplying the oxidant includes supplying the at least one of the dual-duty agent and the oxidant to the production well via an auxiliary well that intersects the production well.
[0234] US6. The method of paragraph US3, wherein the producing includes producing from a production well that extends within the subterranean formation, and further wherein the supplying the dual-duty agent and the supplying the oxidant include supplying the dual-duty agent and the oxidant to an injection well that is separate from the production well.
[0235] US?. The method of paragraph US3, wherein the combusting includes producing a gaseous combustion product and pressurizing the subterranean formation with the gaseous combustion product to provide a motive force for the producing.
[0236] US8. The method of paragraph US1, wherein the supplying the dual-duty agent includes supplying the dual-duty agent to the subterranean formation as a liquid dual-duty agent, and further wherein the method includes vaporizing the dual-duty agent within the subterranean formation to generate a vaporous dual-duty agent.
[0237] US9. The method of paragraph US I, wherein the supplying the dual-duty agent includes supplying the dual-duty agent to the subterranean formation as at least one of a gas and a vapor.
[02381 US 10. The method of paragraph US I, wherein the method further includes mixing the oxidant with the dual-duty agent within at least one of a wellbore that extends within the subterranean formation, the subterranean formation, and the heated cone to form a combustible mixture, and further wherein the method includes igniting the combustible mixture within the heated zone.
[0239] US I I. The method of paragraph US1, wherein the supplying the oxidant and the combusting are initiated based, at least in part, on a temperature of the heated zone, and further wherein the supplying and the combusting are initiated to maintain the temperature of the heated zone above a threshold lower heated zone temperature that is greater than 25 C.
[0240] US12. The method of paragraph US1, wherein the supplying the oxidant and the combusting are initiated based, at least in part, on a temperature of the heated and diluted hydrocarbons, and further wherein the supplying and the combusting are initiated to maintain the temperature of the heated and diluted hydrocarbons above a threshold lower hydrocarbon temperature that is greater than 20 C.
[0241] US13. The method of paragraph US1, wherein the supplying the oxidant and the combusting are initiated based, at least in part, on a viscosity of the heated and diluted hydrocarbons, and further wherein the supplying and the combusting are initiated to maintain the viscosity of the heated and diluted hydrocarbons below a threshold viscosity that is less than 3000 cP.
[0242] US14. The method of paragraph US1, wherein the combusting includes combusting a fuel stream that includes the combusted portion of the dual-duty agent and a portion of the viscous hydrocarbons, and further wherein the dual-duty agent comprises at least 80 wt% of the fuel stream.
[0243] US15. The method of paragraph US14, wherein the viscous hydrocarbons comprise less than 20 wt% of the fuel stream.
[0244] US16. The method of paragraph US1, wherein the ceasing the supplying of the oxidant includes ceasing the supplying of the oxidant based, at least in part, on a temperature of the heated zone, and further wherein the ceasing the supplying includes ceasing the supplying to maintain the temperature of the heated zone below a threshold upper heated zone temperature that is less than 750 C.
[0245] US (7. The method of paragraph US I, wherein the ceasing the supplying of the oxidant includes ceasing the supplying of the oxidant based, at least in part, on the temperature of the heated and diluted hydrocarbons, and further wherein the ceasing the supplying of the oxidant includes ceasing the supplying of the oxidant to maintain the temperature of the heated and diluted hydrocarbons below a threshold upper hydrocarbon temperature of less than 350 C.
[0246] US18. The method of paragraph US I, wherein the supplying the dual-duty agent to the subterranean formation includes supplying a predetermined volume of the dual-duty agent to the subterranean formation, and further wherein the ceasing the supplying of the oxidant includes ceasing the supplying of the oxidant responsive to combusting at least 0.5 volume % and less than 15 volume % of the predetermined volume of the dual-duty agent.
[0247] US19.
The method of paragraph US1, wherein the contacting the viscous hydrocarbons with the heated dual-duty agent includes mixing the heated dual-duty agent with the viscous hydrocarbons.
[0248] US20.
The method of paragraph US1, wherein the viscous hydrocarbons include at least one of bitumen, tar, an unconventional hydrocarbon reserve, and a hydrocarbon with a viscosity that is too high to be produced from the subterranean formation using primary hydrocarbon recovery operations and secondary hydrocarbon recovery operations, and further wherein the subterranean formation includes at least one of an oil sands formation, a tar sands formation, and a bituminous sands formation.
[0249] US21.
The method of paragraph US1, wherein the dual-duty agent includes at least one of methane, ethane, propane, butane, pentane, hexane, heptane, octane, nonane, decane, dimethyl ether, an alkane, naphtha, natural gas condensate, and gas plant condensate.
[0250] US22.
The method of paragraph US1, wherein the oxidant includes at least one of oxygen, air, oxygen-enriched air, and a chemical oxidant.
[0251] US23. A
method of enhancing production of viscous hydrocarbons from a subterranean formation, the method comprising:
converting the viscous hydrocarbons to heated and diluted hydrocarbons using the method of paragraph US1; and producing the heated and diluted hydrocarbons from the subterranean formation.
[0252] US24.
The method of paragraph US23, wherein, subsequent to the converting, the method further includes performing a cyclic solvent process to produce a portion of the viscous hydrocarbons from the subterranean formation.
[0253] US25.
The method of paragraph US23, wherein, prior to the converting, the method further includes performing a cyclic solvent process to produce a portion of the viscous hydrocarbons from the subterranean formation.
[0254] U526.
The method of paragraph US23, wherein the converting forms a portion of an initial production-enhancing process, wherein, subsequent to the converting, the method 2012E1\4246-CA
further includes performing a subsequent production-enhancing process, and further wherein the subsequent production-enhancing process includes at least one of in situ combustion, cyclic steam injection, steam assisted gravity drainage, solvent assisted steam assisted gravity drainage, solvent assisted gravity drainage, steamflood, heated solvent, non-heated vapor extraction, and heated vapor extraction.
[0255] US27. The method of paragraph US23, wherein the converting forms a portion of a subsequent production-enhancing process, wherein, prior to the converting, the method further includes performing an initial production-enhancing process, and further wherein the initial production-enhancing process includes at least one of in situ combustion, cyclic steam injection, steam assisted gravity drainage, solvent assisted steam assisted gravity drainage, solvent assisted gravity drainage, steamflood, heated solvent, non-heated vapor extraction, and heated vapor extraction.
[0256] US28. A viscous hydrocarbon production assembly, comprising:
a wellbore that extends between a surface region and a subterranean formation that includes a viscous hydrocarbon;
a dual-duty agent supply system that is configured to selectively supply a dual-duty agent through the wellbore and to the subterranean formation;
an oxidant supply system that is configured to selectively supply an oxidant through the wellbore and to the subterranean formation; and a controller that is programmed to control the operation of the viscous hydrocarbon production assembly using the method of paragraph US1.
[0257] US29. The viscous hydrocarbon production assembly of paragraph US28, wherein the assembly further includes a heated and diluted hydrocarbon production system that is configured to produce a heated and diluted hydrocarbon stream that includes heated and diluted hydrocarbons from the subterranean formation.
[0258] US30. The viscous hydrocarbon production assembly of paragraph US29, wherein the heated and diluted hydrocarbon production system is configured to produce the heated and diluted hydrocarbon stream from the wellbore.
[0259] US31. The viscous hydrocarbon production assembly of paragraph US29, wherein the wellbore forms a portion of an injection well, wherein the assembly further includes a production well that extends between the surface region and the subterranean formation, wherein the injection well is separate from the production well, and further wherein the heated and diluted hydrocarbon production system is configured to produce the heated and diluted hydrocarbon stream from the production well.
[0260] US32. A
method of heating and diluting viscous hydrocarbons within a .. subterranean formation, the method comprising:
continuously supplying a dual-duty agent to the subterranean formation;
periodically supplying an oxidant to the subterranean formation;
combusting a combusted portion of the dual-duty agent with the oxidant in a heated zone of the subterranean formation during the periodically supplying;
flowing an uncornbusted portion of the dual-duty agent through the heated zone to heat the uncombusted portion of the dual-duty agent and generate a heated dual-duty agent;
and contacting the viscous hydrocarbons with the heated dual-duty agent to generate heated and diluted hydrocarbons.
[0261] US33. The method of paragraph US32, wherein the periodically supplying the oxidant includes ceasing the supplying of the oxidant while continuing the supplying of the dual-duty agent to the subterranean formation.
Industrial Applicability [0262] The systems and methods disclosed herein are applicable to the oil and gas industry.
[0263] It is believed that the disclosure set forth above encompasses multiple distinct inventions with independent utility. While each of these inventions has been disclosed in its preferred form, the specific embodiments thereof as disclosed and illustrated herein are not to be considered in a limiting sense as numerous variations are possible. The subject matter of the inventions includes all novel and non-obvious combinations and subcombinations of the various elements, features, functions and/or properties disclosed herein.
Similarly, where the claims recite "a" or "a first" element or the equivalent thereof, such claims should be understood to include incorporation of one or more such elements, neither requiring nor excluding two or more such elements.
[0264] It is believed that the following claims particularly point out certain combinations and subcombinations that are directed to one of the disclosed inventions and are novel and non-obvious. Inventions embodied in other combinations and subcombinations of features, functions, elements and/or properties may be claimed through amendment of the present claims or presentation of new claims in this or a related application. Such amended or new claims, whether they are directed to a different invention or directed to the same invention, whether different, broader, narrower, or equal in scope to the original claims, are also regarded as included within the subject matter of the inventions of the present disclosure.