CN1932237A - Flue gas injection for heavy oil recovery - Google Patents

Abstract

A variety of methods for thermal recovery of natural gas and bitumen from a formation containing the latter. In general, the methods incorporate a series of existing, but previously uncombined technologies. A modified flue gas from the steam generators conventionally used in a SAGD recovery operation is injected into the formation to enhance recovery with the produced fluids, natural gas, bitumen, inter alia are further processed. The injection of the flue gas conveniently is disposed of and further acts to repressurize the formation which otherwise becomes depressurized when depleted of natural gas. Accordingly, environmental and economic advantages are realized with the methodology.

Description

The flue gas that is used for heavy oil recovery injects

Technical field

The present invention relates to utilize in subterranean strata, inject flue gas from the rock stratum hot extraction value.

Background technology

In heavy oil industry, very wide classification is arranged for heavy oil.These classification are based on the viscosity and the density of material basically, and are divided into following a few class usually:

I) heavy oil in

25°＞°API＞18°

Can flow under the 100cP＞μ＞10cP, storage condition

Ii) extra heavy oil

20°＞°API＞12°

10000cP＞μ＞100cP need comprise that the storage driving is infused in interior production enhancing technology as heat or water/solvent

Iii) oil-sand and pitch

12 ° of＞° API＞6 ° need to excavate or heat is driven

μ＞10000cP need comprise that the storage driving is infused in interior exploitation enhancing technology as heat or heat/solvent.

In view of may be in Canada, Central America, Russia, China and the world huge heavy oil of existing of other area and the known value of pitch reserves, various complete extractions and treatment technology have appearred.

At present, existing pitch and extra heavy oil storage are to use improved thermal recovery technology to exploit, and cause recovery ratio between 20-25%.Prevailing thermal recovery technology is that steam injects, and wherein the heat content from steam is passed to oil by condensation.Certainly, thus this can reduce oil viscosity and makes and can carry out gravity flood and collection.Injection can be driven (CSS) by known cyclic steam, be handled up and SAGD oil (SAGD).

Although SAGD is used just more and more widely, still there is several places deficiency of relevant efficient aspect in it.One is caused the aspect of huge cost is exactly the fuel that is used to drive the steam generator that produces steam in jection.Optimal fuel is natural gas, but its expense can significantly reduce whole efficiency, and this problem is also mixed with all can discharge the fact of the greenhouse gases (GHG) of different amounts in the steam generator running that uses any hydrocarbon fuel.For example, can produce the carbon dioxide of 8000-15000 metric ton about every day for the pitch that obtains steam in jection and acquisition 100000BOPD.

Another problem of SAGD method is for improving the required upgrading of value of the product that is obtained.

Briefly mention as top institute, another factor that influences SAGD is that recovery ratio is limited.

For improving described some restriction, the someone has proposed to use the substitute fuel outside the natural gas, to reduce the influence that natural gas constantly increases at least.Be presented to the US6 of Warchol on March 11st, 2003, disclose a kind of suitable fuel of manipulating for SAGD in 530,965.The document has been instructed the pre-dispersed residual oil of preparing in a kind of aqueous matrix, and its incendivity is as substitute fuel.

Consider the problem that prior art exists, still expectation obtains efficient that a kind of method improves the SAGD operation, reduces the formation of excessive GHG and by providing a kind of substitute fuel with hot property of natural gas to reduce cost.

Summary of the invention

The present invention has all desired characteristics and advantages that are celebrated with the green environmental sound technology of energy efficiency height, high yield.

One aspect of the present invention is to provide a kind of improved more high efficiency thermal recovery technology that has.

Being on the other hand an of embodiment provide a kind of from the subterranean strata that contains heavy oil and pitch the method for exploitation heavy oil and pitch, comprising: a kind of fuel is provided; Combustion fuel is used to inject the injection flue gas of rock stratum with generation in the flue gas recirculation loop; With flue gas is injected the rock stratum with displacement heavy oil and pitch.

Another aspect of one embodiment of the invention is to provide a kind of method of exploiting heavy oil and pitch from the subterranean strata that contains heavy oil and pitch, comprising: a kind of fuel is provided; Combustion fuel is used to inject the flue gas of rock stratum with generation in the flue gas recirculation loop; With flue gas is injected the rock stratum with the displacement heavy oil, pitch and natural gas.

Description of drawings

After so probably having described the present invention, present invention is described with reference to the accompanying drawing that preferred embodiment is described below, wherein:

Fig. 1 is the schematic diagram according to the general technology of an embodiment;

Fig. 2 is the more detailed maps of Fig. 1;

Fig. 3 is to the illustration of the carbon dioxide enriched oxygen demand of flue gas on butt;

Fig. 4 is to the illustration of the carbon dioxide enriched oxygen demand of flue gas on wet basis;

Fig. 5 is the natural gas steam generation schematic diagram in the SAGD environment;

Fig. 6 is that pitch or the emulsion fuel steam in the SAGD environment produces schematic diagram;

Fig. 7 is that the residual oil emulsion fuel steam in the SAGD environment produces schematic diagram;

Fig. 8 is the schematic diagram of combined heat and power flue gas squeeze operation;

Fig. 9 is the schematic diagram of combined heat and power generating operation.

Numerical reference identical in manual is represented identical key element.

The specific embodiment

As known in the art, unless otherwise stated, SAGD refers to SAGD oil, SYNGAS refers to forming gas, and OTSG refers to the single current steam generation, and GHG refers to greenhouse gases, BOPD is the produce oil barrelage in a few days, COGEN refer to generate electricity or compression service and heat utilization and steam generation unite generation, HRSG refers to the waste heat recovery steam generator, " heavy oil " comprises heavy oil, extra heavy oil and pitch.

In Fig. 1, shown the schematic diagram of one embodiment of the invention.Numeral 10 is briefly represented whole technology.A kind of mixture that has mixed air, fuel and the oxygen of flue gas recirculation (FGR) stream is supplied to steam generatingsystem 12 to producesteam 16 and flue gas 35.Selectflue gas 35 exploitation from the rock stratum of containing them of the mixture generation enrichment of described air, fuel, oxygen and FGR, more detailed description is arranged below with optimization gas and heavy oil.

Thefuel 20 that is contained in any air or oxygen mixture can be selected from any suitable hydrocarbon fuel, and its non-limitative example comprises natural gas, pitch, fuel oil, heavy oil, residue, emulsion fuel, heterogeneous super-fine atomization residual oil (trade mark of MSAR, Quadrise Canada Fuel Systems), asphaltene, coke (petcoke), coal and combination thereof.

To before injecting the rock stratum, handle or modification from theflue gas 35 of system 12 a processing operation 14.The byproduct that is produced byprocessing unit 14 can randomly be recovered.This flue gas can contain a large amount of gaseous compounds, comprises carbon dioxide, carbon monoxide, nitrogen, nitrogen oxide, hydrogen, sulfur dioxide, synthesis gas etc.Under the burning condition of excess oxygen, wherein oxygen content is present in theflue gas 35, andflue gas 35 will mainly contain carbon dioxide, nitrogen and water vapour.Theinjection gas 45 of treated mistake is injected into gas and the heavy oil rock stratum of generally being represented bynumeral 18, is shown as a kind of SAGD (SAGD oil) rock stratum in an embodiment.The method relates to uses steam to help reduce the viscosity of thickness hydrocarbon to promote flowability.Natural gas, pitch and various other hydrocarbon that has value but more or less can not exploit are economically in the past also contained in these rock stratum.Steam 16 fromsystem 12 is introduced in therock stratum 18 as shown in the figure.

Now, because the combining of the injection of flue gas loop and theflue gas 45 of modification, the gas in therock stratum 18 is become can have been exploited effectively.The combination of these operations has caused success of the present invention.Advantage is that technology described herein not only can be applied to the rock stratum of gas on pitch, can also be applied to contain the rock stratum that gas, pitch or its combined location are pressed close to.As a kind of non-limiting example, also can exploit laterally or the rock stratum of vertically replacing.This briefly is presented among Fig. 1, with numeral 18 ' expression.The flue gas of modification is injected into 18 ' 45 '.The advantage of this technology also can be used for SAGD chamber or the blowdown discarded, and wherein flue gas can be injected into not only keeping heavy oil recovery, and displacement heavy oil.

Thenatural gas 25 that cements out fromrock stratum 18 be collected and can adopt extra unit operations or wherein a part can recycling carry out the system fuel as steam generation.After this a step does not show in Fig. 1, but within those skilled in the art's limit of power.

Then, the flowed extraction liquid that contains pitch bynumeral 22 expressions is carried outoil processing operation 24, itsmedium pitch 26 processed water entrainments of removing are to obtain salable product.Recoveredwater 26 is further handled in a suitable unit for treatingwater 28 to remove deasphalting, sclerosis compound, silica and any other unwanted compound to obtain to be suitable for the water of making boiler feed water 30.For realizing that the result who needs can adopt any suitable water treatment operation.Boiler feed water 30 can recycling enter the manufacturing thatsystem 12 is used forsteam 16 then.In addition, handle the water of operating from flue gas, promptly can be in the recycling of 28 places, equally to increase efficient with numeral 52 water of representing.

In general description after the whole technology, can find out obviously that this technology has many advantages.These advantages comprise:

I) the efficient and environmental safety of harmful smoke is handled;

The ii) gas production rate from the rock stratum of Ti Gaoing;

Iii) the thermal recovery operation of Ti Gaoing is so that per unit steam produces more pitch;

Iv) carbon dioxide sequestration is to reduce the GHG discharging;

The v) volume replacement in the rock stratum; With

Vi) any combination of these characteristics.

Referring now to Fig. 2, demonstration be more detailed diagram according to the method for an embodiment.In the illustrated embodiment, providing anair separator unit 40 to be used for carrying out gas inject fuel and oxygen insteam generating system 12 before separates.Optional provide flue gas recirculation (FGR) loop for system 12.Flue gas recirculation is used forreduction system 12 interior combustion zone temperature so that the performance of steam generator all is consistent at the gamut of the oxygen therapy amount that is used for the steam generation process for combustion air.For higher oxygen content, if there is not flue gas recirculation (FGR), the heat generator temperature will surpass the design of steam generator limit.Leave the flue gas in loop and handled inprocessing unit 14, here it stands the removal of suspended particulates, as electrostatic precipitation ordust storage chamber 44, and in the ash discharge of 46 places.Before being compressed at 48 places, the gas of so handling also further dewatered 50 by further chilling.Can be recycled to unit for treatingwater 28 or the MSAR that will discuss hereinafter forms thestage 70 from thewater 52 of described operation.Bi-product gas from 14 if produced, can be separated from flue gas and be reclaimed and be used to further operation, for example is used for the CO fuel of heating furnace or boiler, is used for the SO2 of commercial distribution or is used for the H2 oxygen supply of asphaltic nature.

In this embodiment, leaving the pitch ofoil processing unit 24 can partially or completely handle in the modifyingapparatus 56, pitch or synthetic crude at 58 output upgradings, and the hydrocarbon mixture of being made up of pitch, residual oil, asphaltene or coke etc. can be further processed into MSAR, a kind of in U.S. Pat 6,530, the highly effective fuel that goes through is arranged in 965, mainly be included in the pre-dispersed residual oil in the aqueous matrix, it can reduce the fuel cost of steam generating system running greatly.Traditionally, the latter is to use natural gas, and its cost is considerably beyond the cost that uses MSAR.Randomly, described fuel can replace with those fuel of previous instruction or augment.

Fig. 3 and 4 has shown the carbon dioxide enriched oxygen demand of flue gas on butt and wet basis with chart respectively.When in steam generator operation, introducing pure oxygen, will comprise still less nitrogen for a certain amount of carbon dioxide flue gas 35.Therefore not only the amount of flue gas has reduced, and the gas concentration lwevel in the gas ofhandling 45 has improved.For example, with reference to figure 3, when used oxygen content convergence 100% (0% combustion air), the composition of the flue gas of handling is near 100%CO on butt₂, comprise compounds such as a spot of carbon monoxide, sulfur dioxide, nitrogen dioxide.Fig. 3 represents the main composition of theinjection gas 45 handled.With reference to Fig. 4, with captionflue gas stream 35 be main composition before carrying out flue gas in 14 handles.

Fig. 5 is the schematic diagram in natural gas production of steam loop.In this embodiment, at least a portionnatural gas 20 of being replaced can recycling as the fuel that drives steam generating system 12.This represents with numeral 60.The injection flue gas of enrichment is injected into the replacement product fluid, and wherein said injection flue gas can self-definedly comprise the nitrogen of 30%-50% and the carbon dioxide of 70%-50%, and pitch, natural gas, water etc. are at 62 upgradings.The selection of the operation of carrying out in 62 places will be depended on the product of expectation.

Thewater 52 that reclaims fromfume treatment unit 14 can be recycled to 62.

In Fig. 6, steam generation realizes that by using a kind of liquid substitute fuel shown in the embodiment is a kind of pitch or astatki, and perhaps, described pitch or heavy oil are transformed into emulsion fuel.Leave the processed pitch that is positioned atpipeline 66 that central authorities handleequipment 62 can turn to make a part of material onlypipeline 68 directly as heavy fuel oil or, directly enter emulsification unit and be used to make a kind of substitute fuel.The emulsification unit stage is represented with 70.Reclaim and the water of the additional amount of circulation can be diverted and introduceunit 70 bypipeline 72 52.In the emulsion fuel unit, the chemical agent that is fit to is added into bituminous material (surfactant or the like) to make substitute fuel.In a single day substitute fuel prepares, and just leaves emulsification unit and can be used as fuel to be introduced into to drive steam generating system 12.Come the natural gas of the gas that quilt is replaced in thecomfortable rock stratum 18 to stop no longer to consume the natural gas of any further amount as fuel and this process.So, in case emulsification unit available and stable after, this process only depends on the substitute fuel that himself produces.

In Fig. 7, shown a kind of variant of Fig. 6, wherein added asphalt quality and improved device 76 to the unit operations of central processing unit.Thematerial 66 that leaves central processing unit by upgrading, forms heavy residual oil andleaves 80 and can be made into the substitute fuels of emulsification then and be introduced intovapour system 12 as Fig. 6 in upgrader 76.Thing followed benefit is that oil pitch quality is risen to deasphalted oil or synthetic crude.

In Fig. 8, one embodiment of the invention are used in combination with gas combined heat and power (COGEN)equipment 600 of routine to improve whole thermogravimetric oil extraction operation.Especially, when combining the present embodiment,steam generator 12 as previously described can compatibly be equipped with COGEN waste heat recovery steam generator (HRSG) and drive the required energy of handling of injection flue gas compressor to make required whole steam in jections and to provide.

Fig. 9 has illustrated another embodiment, andsteam generator 12 combines to produce electric energy with COGENequipment 600 whereby.The electric energy that is produced can be used to drive the flue gas compressor handled and provide power so that it can be self-sufficient forcomplete equipment 10.

Claims (25)

1. the method for exploitation heavy oil and a pitch from the subterranean strata that contains heavy oil and pitch comprises:

A kind of fuel is provided;

Combustion fuel is used to inject the flue gas of rock stratum with generation in the flue gas recirculation loop; With

Flue gas is injected the rock stratum to replace described heavy oil and pitch.

2. according to the process of claim 1 wherein that described fuel is a kind of fossil fuel.

3. according to the method for claim 2, wherein said fuel is selected from natural gas, fuel oil, heavy oil, residual oil, emulsion fuel, heterogeneous super-fine atomization residual oil, asphaltene, petroleum coke, coal and combination thereof.

4. according to the method for claim 1-3, wherein said fuel burns with oxygen and air in steam generator.

5. according to the method for claim 1-4, also be included in and inject the described rock stratum step of the described flue gas of modification before.

6. according to the method for claim 5, comprise and remove the bi-product gas that in described modification procedure, produces.

7. according to the method for claim 6, wherein said bi-product gas comprises at least a in oxygen, carbon monoxide, nitrogen, nitrogen oxide, sulfur oxide and the carbon dioxide.

8. according to any one method among the claim 5-7, comprise and remove the particulate ash.

9. according to any one method among the claim 5-8, the step of the described flue gas of wherein said modification comprises takes off these unit operations of particulate, chilling, compression and dehydration.

10. according to any one method among the claim 5-9, the flue gas of wherein said modification is injected into described rock stratum with to the supercharging of described rock stratum and discharge natural gas in the described rock stratum.

11. according to the method for claim 10, wherein heavy oil is cemented out from described rock stratum in pressurization.

12., further comprise step with the described heavy oil that displaces of reforming unit operation modification according to the method for claim 11.

13. according to the method for claim 12, wherein said reforming unit operation comprises from anhydrating by removing in the oil that cements out the described rock stratum.

14. according to the method for claim 13, wherein the water that is removed of at least a portion is recycled and enters described steam generator.

15. according to any one method among the claim 12-14, wherein at least a portion is converted to heterogeneous super-fine atomization residual oil with as combustion fuel from the residual oil of upgrading heavy oil.

16. one kind from SAGD oil rock layer and geographical position near the method for gas extraction and pitch at least a rock stratum the rock stratum, wherein said SAGD oil rock layer comprises the gas that is positioned on the pitch in the volume of described rock stratum, the step of the method comprises:

Provide the flue gas recirculation loop to produce the flue gas of modification;

The flue gas of described modification is injected described rock stratum to displace described pitch within described rock stratum to be enough to replace the pressure that is positioned at the described gas on the described pitch;

The gas and the pitch of extraction displacement;

Increase or keep pressure to one pressure that equates with the previous pressure that injects described modification flue gas substantially of described volume with the flue gas of described modification.

17. according to the method for claim 16, the gas of wherein said displacement comprises the natural gas that does not contact with the direct geographical position of pitch.

18., comprise that further the composition that forms a kind of described modification flue gas is so that the maximized step of the volume of substitution gas according to the method for claim 16.

19., wherein after the gas-field exploitation of displacement, continue input modification flue gas to basic identical with further Isolation warm house gas GHG with original geology pressure according to any one method among the claim 16-18.

20. according to the method for claim 18 or 19, the step of the composition of a kind of described modification flue gas of wherein said formation comprises that the oxygen concentration that keeps in the described flue gas is in excessive, stoichiometry or be lower than stoichiometry.

21. according to any one method among the claim 18-20, the described composition of wherein said flue gas comprises the nitrogen of 0%-79% by volume.

22., further comprise the step that from described modification flue gas, produces bi-product gas according to any one method among the claim 16-21.

23. according to the method for claim 22, wherein said bi-product gas comprises at least a in hydrogen, carbon monoxide, nitrogen, nitrogen oxide, sulfur oxide and the carbon dioxide.

24. according to any one method among the claim 16-23, wherein said flue gas recirculation loop uses the hydrocarbon fuel that is selected from natural gas, fuel oil, heavy oil, pitch, residual oil, emulsion fuel, heterogeneous super-fine atomization residual oil, asphaltene, petroleum coke, coal and combination thereof to act as a fuel.

25. one kind from SAGD oil rock layer and geographical position near the method for gas extraction and pitch at least a rock stratum the rock stratum, wherein said SAGD oil rock layer comprises the gas that is positioned on the pitch in the volume of described rock stratum, the step of the method comprises:

Steam produces the stage, is used to produce the steam that injects described rock stratum;

In the flue gas recirculation stage, be used for the flue gas that modification is used to inject described rock stratum;

In the injection stage, the flue gas of modification is injected described rock stratum be positioned at the gas on the described pitch with displacement and keep the pressure of described rock stratum or the supercharging of described rock stratum;

The processing stage, handle the substitution gas of extraction and the liquid that discharges from the described injection stage.

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