CN103362489A - Method used for stratum hydraulic fracture - Google Patents

Abstract

The invention provides an economical and effective method used for stratum hydraulic fracture. Strong proppant briquettes are uniformly placed in all length direction of cracks to improve the hydraulic fracturing conductivity. One of the method comprises the following steps: in the first stage, a fracturing fluid containing a thickening agent is injected into a borehole to produce a crack in the stratum; in the second stage, a proppant is periodically led to the injected fracturing fluid to feed the proppant to the produced crack so as to form proppant briquettes for preventing the crack from being closed, as well as a passage arranged between the briquettes and used for the formation fluid to flow through, wherein in the second stage or subsidiary stages thereof, a reinforcing material or a strutting material or the both is (are) additionally introduced to enhance the strength of the proppant briquettes formed in the fracturing fluid.

Description

The method that is used for the fracturing on stratum

The application's dividing an application for No. 200680051820.7 application for a patent for invention of " method that is used for the fracturing on stratum " that be the denomination of invention submitted on January 27th, 2006.

Technical field

The present invention relates to the fracturing in the stratum, more particularly, relate to for the method for optimizing fracture conductivity.

Background technology

The well that hydrocarbon (oil, natural gas etc.) passes the hydrocarbon-containiproducts stratum by probing obtains from the stratum.This provides the part stream for hydrocarbon arrives ground.For making hydrocarbon " output ", namely advance to well from the stratum and finally march to ground, must have enough unimpeded stream.

Fracturing is by the high conductance crack from well to reservoir being set or making the high conductance crack extend to the major measure that improves well yield the reservoir from well.During the phase I, the fracturing fluid injects the stratum by well with high speed and high pressure.The fracturing fluid charge velocity surpasses the infiltration rate on stratum, thereby produces the hydraulic pressure that increases at sand face (sandface).When pressure surpasses threshold, stratum or rock rupture and generation crack.This formation fracture more has permeability than formation pore.

During the next stage, proppant is deposited in the crack, stops rear closure in case crack arrest is sewn on to inject.The final supported crack that forms can make recoverable fluid, and namely oil, gas or the mobile of water are improved.Sand, gravel, bead, walnut shell, ceramic particle, sintering alumina and other materials can be used as proppant.

The fracturing fluid is to contain for example aqueous solution of solubilized polysaccharide of thickener, in order to provide enough viscosity to transmit proppant.Typical thickener is polymer, for example guanidine that glue (phytogeneous polysaccharide, plant polyose) and guanidine that gum derivative (hydroxypropyl guanidine that glue, carboxy-methyl hydroxy propyl guanidine that glue).Other polymer also can be used as thickener.Have your water meter of glue of guanidine and reveal the linear gel that has with the proportional viscosity of polymer concentration.Providing the crosslinking agent of combination to be used to form enough strong coupling between polymer chain increases gel viscosity and produces viscoplasticity.Be used for your crosslinking agent commonly used of glue of guanidine and comprise boron, titanium, zirconium and aluminium.

The proppant retention agent be generally used for that fracturing processes than during the after-stage, the proppant of putting into the stratum with restriction flows backwards.For example, proppant can be coated with the curable resin that is activated under downhole condition.Different materials for example fiber bundle or fibrous material or deformable material also is used for keeping the proppant in crack.Can infer that fiber forms three-dimensional network in proppant, thereby to its reinforcement and limit its refluence.

Hydraulic fracture conductivity and fracture length are depended in the success that fracturing is processed.Fracture conductivity is the product of proppant permeability and crack width; Unit is typically expressed as millidarcy-foot.Fracture conductivity is affected by a plurality of known parameters.The distribution of proppant particle size is a key parameter that affects crack penetration.Proppant concentration between the fracture surface is another key parameter (poundage with the proppant of every square foot of fracture surface represents) and affects crack width.Can consider to adopt high-intensity proppant, have the fluid (making the minimized ability of gravitational settling in the crack) of good proppant delivery characteristic itself, high proppant concentration or large proppant and improve fracture conductivity as means.The low yield that the proppant delivery of weak material, difference and narrow crack all can cause well.Relatively inexpensive low-intensity material for example sand is used for having the fracturing on the stratum of less internal stress.The material of higher cost such as pottery, alumina etc. are for the stratum with higher internal stress.The characteristic that the fluid that produces and the mutual chemical action between the proppant can significantly change proppant.Thereby, because oil well and gas well turn round for many years usually, therefore should consider the long-term resistance to crusing ability of proppant.

Proppant pack must generate the layer that has higher hydraulic conductivity than formation rock on every side.Proppant pack in the crack can be used as permeable loose structure modeling, and formation fluid is described by well-known Darcy law (1) or Forchheimer formula (2) usually by flowing of this layer:

$1)\∂P/\∂x=-(\mathrm{\μu}/k);$

$2)\∂P/\∂x=-[(\mathrm{\μu}/k)+{\mathrm{\β\ρu}}^2]$

Wherein

P is fluid pressure in the crack;

X is the distance from well along the crack;

μ is the viscosity of formation fluid;

U is (infiltration) speed that flows of formation fluid;

K is the permeability of proppant pack;

β infiltrates the coefficient that is called the β factor of the non-linear correction of law for describing Darcy;

ρ is the density of formation fluid.

The result that fracture permeabgility multiply by crack width is called " hydraulic conductivity ".The most important aspect of fracture design is that the special formation condition is carried out hydraulic conductivity optimization.Fracture design theory and method have abundant description in many pieces of scientific and technical articles and monograph.Reservoir Stimulation, 3^Rd, Economides, Michael J. and Nolte, Kenneth G., John Wiley and Sons(1999) and provide the good example of the list of references of good fracture design method.

The crack optimizing process should be in proppant strength, hydraulic fracture conductivity, proppant distribution, material cost and is carried out realizing between the cost that fracturing processes balanced in particular reservoir.The situation of large proppant has been explained do compromise in optimizing process.When using the major diameter proppant, the remarkable increase of hydraulic fracture conductivity is possible.Yet under given internal formation stress, when being subject to higher closing up of cracks stress, the major diameter proppant can crushed to a greater extent, cause effective hydraulic conductivity of proppant pack to descend.In addition, proppant particles is larger, their more cross-over connections and blocking near the crack decanting point.

Withstand voltage broken ability according to proppant is selected special proppant, and described proppant provides enough fracture conductivity when standing closing up of cracks stress; And it can flow into hydraulic fracture at low cost dearly.According to volume and the quality that the fracturing process is used, proppant ranks the second after the water.With the sand facies ratio, ceramic proppant has the better β factor and higher intensity.Yet, the manyfold of the cost that the cost height of ceramic proppant shakes out.Therefore, for the fracturing that utilizes proppant, the improvement of fracture conductivity needs huge cost, usually reaches 20 to 60% of total cost that traditional fracturing processes.

Except above-mentioned factor, other proppant characteristics is still arranged so that nytron the production of material complicated.At first, formation fluid usually walk around for the treatment of most of fluid.(remain in the conductibility in the fluid breaks crack in the proppant stages.) work place study shows, in the natural gas well amount of recovery of fracturing fluid from the crack average only by in the processing procedure the injection fluid 20% to 50% or still less.Formation fluid may be only along a plurality of channel flow of the form of the one-tenth in the proppant pack " finger ", or in the fracture clean processing procedure only by the part of proppant pack near well.The crack part that comprises remaining viscogel stops Fluid Flow in A, thereby reduces effective hydraulic fracture conductivity.Reducing afterwards fracturing fluid viscosity in processing is to increase fracturing fluid from the effective means of the recovery of proppant pack porosity.Add the reduction that the material that is called " gel breaker (breaker) " promotes gel viscosity.Gel breaker has multiple mechanism of action, but the most common situation is they also reduce polymer solution thus with the length that reduces them by the polymer pyrolysis chain viscosity plays effect.Different gel breakers are characterised in that, such as the activation of the reaction rate between gel breaker and the polymer, described specific gel breaker or the parameter of activation releasing temperature.Better fracture clean can realize by using high breaker concentration, but too high breaker concentration can cause gel viscosity to reduce too early, and this may damage Treatment Design and cause finishing too early of processing, namely is blocked.The gel breaker of delayed-action for example method for packing is developed be used to addressing this problem.The gel breaker of encapsulation is for example oxidizer granules of active gel breaker chemicals, and it is coated with the protection housing that oxidant and polymer are isolated and postponed their reaction.Number of mechanisms in the acting on of mechanical stress by being included in closing up of cracks place is destroyed housing and is discharged gel breaker.The gel breaker of encapsulation can so that use higher breaker concentration in the fracturing fluid, therefore can improve the degree of fracture clean.

Another factor that reduces fracture conductivity is the pore plugging in the proppant pack, described obstruction comes from the formation particles that forms in the fracturing process, the proppant particles of proppant crushing formation and fluid (The Impact of Non-Darcy Flow on Production from Hydraulically Fractured Gas Wells that can not be miscible, SPE Production and Operations Symposium, 24-27 day in March, Oklahoma City, Oklahoma, 2001; A Study of Two-Phase, Non-Darcy Gas Flow Through Proppant Pacs, SPE Production﹠amp; Facilities, the 4th phase of the 15th volume, in November, 2000).Therefore, obviously, wherein formation fluid is flowed through by the channel network that generates and can not increased by following number of mechanisms the hydraulic conductivity in crack by the crack of the fine pore in the proppant pack: reduce inertia loss, raising fracturing fluid removing, reduce to produce the capillary force of the significant two phase flow pressure loss and by catching the proppant fragment elimination pore constriction shutoff of stratum fin and crushing.

In recent years, the frac treatment in the many low permeability formation in North America is by utilizing the low viscosity water power fracturing fluid do not contain proppant or only to contain a small amount of proppant to carry out pumping.The method has a plurality of titles, and wherein the most frequently used is " hydraulic pressure splits (waterfrac) ".Hydraulic pressure splits the crack that processing produces and does not in fact contain proppant.Can estimate that between crack generation and propagation periods, the fracture surface that produces is offset relative to each other.The dislocation of the irregular surface feature (rough and uneven in surface) that causes prevents that two fracture surfaces from forming tight seal when closure.It is reported that a small amount of proppant of adding can strengthen the effect of the fracture surface of irregular and dislocation.Yet because transmission property is relatively poor, proppant trends towards accumulating in the below of well-case perforating, and the base portion of most possible hydraulic fracture along producing gathers.Because higher and because the proppant delivery scarce capacity the low viscosity of fracturing fluid (all because of) along the narrow sedimentation rate of hydraulic fracture proppant in fracturing fluid, so described gathering can occur., hydraulic pressure stops and when fracturing fluid being injected stop fracture length and reducing highly immediately when splitting.This will compress proppant slightly, and described proppant remains " sand dune shape " at the fracture base place near well.Because the finite length on sand dune, width and intensity is limited (adopting low-intensity sand) usually usually, hydraulic pressure splits and usually is characterised in that generation crack (Experimental Study of Hydraulic Fracture Conductivity Demonstrates the Benefits of Using Proppants short, low conductivity, SPE Rocky Mountain Regional/Low-Permeability Reservoirs Symposium and Exhibition, 12-15 day in March, the Denver, the state of Colorado, 2000).

Above-mentioned showing, hydraulic pressure splits the network that flows through narrow passage by formation fluid and produces, and described narrow channel network is because that surperficial rock flaw causes is fully closed and produce in the crack, and namely hydraulic pressure splits to process and produces low conductivity fractures.Improve the conductive a kind of method of fracturing and be and construct proppant cluster in the crack, this is with to construct continuous proppant pack different.United States Patent (USP) 6776235 discloses a kind of method for stratum hydraulic fracturing, comprising: the starting stage, the described starting stage is injected well with the fracturing fluid, and described fracturing fluid comprises thickener to produce the crack in the stratum; And alternating phases, described alternating phases will comprise the fracturing fluid of proppant and periodically introduce in the well, prevent the proppant cluster of the column form of closing up of cracks with formation, the described difference that comprises the fracturing fluid of proppant is that the ability of their transmission proppants is different, so difference is the proppants settle down rate.The method alternately adopts the stage and the stage that does not contain the fracturing fluid of proppant of the fracturing fluid that is loaded with proppant.Can be conditioned by changing Fluid Transport characteristic (for example viscosity and elasticity), proppant density, diameter, concentration and fracturing fluid charge velocity at the deposition of every one-phase proppant in the crack.

The method of this patent provides and has produced proppant cluster or island body and produce the passage that supplies formation fluids in the crack between proppant cluster or island body.Yet the cycle of the proppant that this method adopts injects the every part that relates to proppant and at first transmits along well; Then, the perforation by tubing string enters the crack; And further pass through the crack along the length in crack.Owing to contain proppant and have different proportion with the fracturing fluid that does not contain proppant, but so contain the fluid sedimentation of proppant or be positioned under the described fluid that does not contain proppant.This sedimentation causes the non-uniform Distribution of the proppant cluster in the crack.

Summary of the invention

Term " proppant " is generally used for referring to sneaking into fracturing fluid and being pumped the granular materials that enters well during fracturing is processed.This proppant forms the permeable porous layer of formation fluid (bed), stops formation closure and keep fracture face separated after finishing dealing with.In conventional process, the technician can select from providing polytype granular materials of required permeability (hydraulic conductivity) with optimum cost under the closure stress on given stratum.Common proppants is senior selected quartz sand; Aluminosilicate pottery, sintering alumina and silicate ceramic porcelain bead; And the polytype material that is coated with different organic resins.The proppant of being made by walnut shell, bead and organic principle also can be pumped.One of most important factor that proppant is selected is the distribution of sizes of single plastochondria.When all other conditions are identical, to compare with having identical average particle size particle size but have the Equivalent strut agent that wide proppant distributes, the proppant that has narrow distribution of sizes in the crack has higher permeability.

These standard convention about the choice and operation of proppant are not suitable for the present invention described herein.In present patent application, term " proppant and/or backing material " is defined as " being added in the fracturing fluid to produce any solid material, plastochondria, fiber or other material of firm and rock-steady structure in the crack ".Equally, all conventional proppants of usually generally acknowledging still are considered to the spendable proppant of the present invention.Yet other material for example sand, metal tape and the pin of sorting in the wide region, dish, abrasive granules, organic and inorfil also is considered to the proppant that arrives involved in the present invention and/or backing material.

Term " fiber " is generally used in following description of the invention and the claim.For the purposes of the present invention, term " fiber " refers to such any material or actual object, and wherein, the arbitrary dimension in the arbitrary dimension in three dimensions and other two dimensions or the length ratio of two dimensions surpass 5:l.This aspect ratio that means object is greater than 5:1.Therefore, the common fiber of being familiar with is the fiber that arrives involved in the present invention.Equally, usually, the band of indication or plate also are the fiber that arrives involved in the present invention by definition.

The invention provides a kind of economical and effective method of the fracturing for the stratum, so that the crack has high hydraulic conductivity for formation fluid.The present invention is created in firm proppant cluster or the island body that distributes on most of fracture surface area, and they can prevent that sides of fracture is closed after finishing dealing with.The cross section that between these island bodies and agglomerate, forms and keep the described passage that opens wide and open region to comprise enough large confession formation fluids by this agglomerate.

Usually, fracturing is processed with two or more stage activities of order and is carried out successively.In the phase I that is commonly referred to as " filling " of most frac treatment, water base or oil based fluids is pumped in the stratum with sufficiently high pressure and speed, to form fracturing.In this phase process, fluid is often by using various thickening agents by clayization; Those skilled in the art can control viscosity to affect the final geometry in crack.The present invention described herein adopts this packing stage.

After packing stage, at once and usually be commonly called continuously the main stage of the pressure break of " driving phase ".In conventional process, this stage is usually directed to pumping and contains the fluid constant or conventional proppants that concentration increases.This produces porous material layer when processing termination.Those skilled in the art will know that how to select applicable proppant for given formation condition, so that the hydraulic conductivity in crack is maximum.In conventional process, usually carry out pumping until finish dealing with when " driving phase ".Usually the end of " driving phase " is called as " trailing " stage.The proppant and/or the fiber that are coated with resin " trailing " in stage are added into, as the measure that refluxes afterwards in processing of control proppant.

Compare, in the present invention, driving phase comprises a series of alternately sub, and the described alternately sub of some of them relates to backing material, hereinafter referred to as " support sub "; Some described alternately subs relate to and carry fluid, hereinafter referred to as " carrying sub ".The sub that comprises at least one sub of backing material and do not comprise backing material is to carry out pumping to the crack.Support the mode of the size of sub and composition so that backing material is assembled forms high-intensity column and the island body that prevents closing up of cracks and form passage for formation fluids between agglomerate.Because the hydraulic conductivity in crack forms by open channels, therefore a part of the present invention allows the backing material composition to may be selected to compressive strength and the corrosion resistance optimization of the island body that makes gained under given reservoir conditions.The permeability of gained agglomerate or island body or unimportant perhaps is less important.

Another aspect of the present invention is that the sub that comprises backing material can comprise and increases before this additional reinforcement and the reinforcement material of proppant cluster.Strengthen and reinforce meaning such any chemistry and/or physical treatment, that is, be used for promoting that granular material is bonded together; Or for increasing the frictional force that particle is kept together; Or when by some applied external force effects, mechanically limit particle separation.The particular instance of strengthening processing can be the resinous coat that causes the mutual tight bond of these particles on fiber (aspect ratio is greater than the particle of 5:1), deformable material and the particle surface.

In many cases, when being introduced in the fracturing fluid, proppant can advantageously introduce reinforcement material, although this reinforcement material can be incorporated in the fluid continuously.

Reinforcement material can be organic and inorganic or organic and inorfil.These fibers also can be processed or be made, and only comprising adhesive coatings, or comprise and are coated with the adhesive coatings that is dissolved in the non-stick substance layer in the fracturing fluid when by the crack.Reinforcement material also can be: the metallic particles with spherical or elongated shape; The plate of organic or inorganic material; Be pottery, the metal or metal alloy that is shaped as plate-like on the diameter; Or be shaped as pottery, the metal or metal alloy of rectangle at length and width, for all these materials, the ratio between any two dimensions in three dimensions is greater than 5:1.

Preferably, second stage also relates to reagent imported increases the proppant of fracturing fluid suspending power in the fracturing fluid.This reagent can be has length much larger than the material of the elongated particle of diameter.

Elongated particle can or be that intermittence is imported in the fracturing fluid continuously with the proppant while individually.

Preferably, elongated particle length is greater than 2mm, and diameter is 3 to 200 μ m.

Proppant particles can only have adhesive coatings, or has and be coated with the adhesive coatings that is dissolved in the non-adhesion substance layer in the fracturing fluid by the crack time.

Under some formation conditions, when adopting said method, can advantageously carry out and relate to the final tail-in stage of proppant being introduced continuously the frac treatment in the fracturing fluid, and proppant has roughly uniformly particle size in this stage.Simultaneously, can in fracturing fluid, introduce reinforcement material and/or have the material of the elongated particle of the proppant suspending power that can strengthen fracturing fluid.

The second embodiment

Other method can be by being configured to the stratum the proppant column of distribution of fracturing form high conductivity fractures.This second embodiment relates to the phase I (packing stage), and in the described phase I, the fracturing fluid that contains thickener is injected in the well; And second stage, in described second stage, proppant is added to the fracturing fluid (and therefore entering the crack that is produced) of injection continuously, in case the crack arrest seam is closed.In the present invention, second stage also relates to periodically to be introduced reagent in the fracturing fluid, to promote forming proppant cluster in the crack that is produced.The open channels that formation fluid flows through is separated proppant.

Be to form proppant cluster, based on import from reagent moment the fracturing fluid through specified time interval how long after, reagent and fracturing fluid react.This time interval is monitored and be changed in processing procedure, triggers reaction between reagent and the fracturing fluid with the diverse location place in the crack that is produced.Also will be at whole fractue spacing by the agglomerate that this reaction forms.Described response delay realizes that by a kind of mechanism in the multiple different mechanism described number of mechanisms includes but are not limited to following mechanism: the chemical composition that changes reagent; Reagent is encapsulated in the housing that is dissolved in the fracturing fluid; Collide and the corrosion housing with other reagent particle and fracture surface; The housing of when closure, between sides of fracture, crushing; Reagent is packaged in the semipermeability housing that expands in fracturing fluid and break; Reagent is encapsulated in allows reagent slowly to be diffused in half film or perforated shell in the fracturing fluid; And reagent is encapsulated in the housing that can dissolve or rinse out.

This reagent can be so that fracturing fluid viscosity is violent, the significantly local additive that reduces, the proppant that carries in the fluid of after this just having processed will be between fracture surface sedimentation or jam.

The fracturing fluid gel breaker that additive reacts when can be in crack controlled release agent.The fracturing fluid gel breaker can be oxidant, enzyme, (crosslinking agent) chelating agent or fluid pH value can be changed to so that the chemical agent of crosslinking agent or the unsettled degree of main polymer chain.Acquired results is the significantly reduced gel breaker that reacts and cause fracturing fluid viscosity with fracturing fluid in arbitrary situation.Catalyzer can be introduced in the fracturing fluid, to increase when needed the reaction rate of gel breaker and fracturing fluid.

Additive also can be the type of destroying the fracturing fluid crosslinking agent, for example but the D-sorbite and the polyvinyl alcohol that are not limited only to chelating agent, the EDTA that is used for the zirconate crosslinked agent and NTA and are used for borate crosslink.These additives can be encapsulated with the housing that has different-thickness or have at the releasing mechanism of the diverse location place in crack release additives.Also can use acid and/or the alkali (base) of encapsulation or delayed release.

The reagent that starts proppant cluster formation in the crack can be the additive that reduces the proppant particles activity.Example is the fiber bundle that is coated with a kind of material, and described material dissolves in fracturing fluid so that fiber hydration and distribution and increase their concentration.These additives also can be the material of the original-shape that recovers them when being heated to a certain temperature, for example be wound in sphere and can stretch or increase the fiber of their volume when being heated.

Additive can be the material with high absorbent capacity.The housing that particle with high absorbent capacity can be coated with in by the crack process or dissolve in fracturing fluid temperature elevation process or during the combination of these situations.

Additive can be plastochondria, fiber or the plate that becomes viscosity at the formation temperature soffit.These elements can have adhesive surface and be coated with the non-adhesion substance layer that is dissolved in the fracturing fluid.

The 3rd embodiment

According to another embodiment of the invention, a kind of method of the fracturing for the stratum relates to: the phase I (filling), in the described phase I, the fracturing fluid that contains thickener is injected in the well; Second stage, in described second stage, proppant is introduced into the fracturing fluid of injection and the crack that produces continuously, to prevent its closure.In addition, described method comprises the phase III, in the described phase III, low viscosity fluid is injected fracturing fluid.Described fluid and forms the passage that the confession formation fluid flows through because the difference between its viscosity and the fracturing fluid viscosity penetrates in the fracturing fluid as the invader that proppant is divided into discrete agglomerate.

Similar to method described in the first embodiment, the second stage among the second and the 3rd embodiment can comprise to be introduced material and/or the reinforcement material with elongated particle and uses the proppant with these same characteristics.Simultaneously, can relate in additional final stage the material that has proppant and the reinforcement material of single-size size roughly and/or have an elongated particle is introduced in the fracturing fluid continuously.

Description of drawings

The following drawings is accompanied by description of the invention:

Fig. 1 shows the fracturing fluid viscosity with respect to proppant concentration.

Fig. 2 is presented at the proppant cluster that is formed in the implementation process of method of the present invention in the crack.

Fig. 3 is presented at the proppant cluster that is formed in the implementation process according to the method for the second embodiment in the crack.

Fig. 4 is presented at according to the implementation process of the method for the 3rd embodiment (from a) to d) and carries out) be formed on proppant cluster in the crack, wherein, when replacing viscous fluid with thin fluids, formed the viscosity dactylozoite.Be the result of numerical simulation shown in the figure.What appear dimmed is the viscous fluid with proppant.What be shown as black is the thin fluids that penetrates proppant pack and produce open channels in filling bed.If the fluid than thickness has yield stress, then can strengthen the stability of formed passage.

The specific embodiment

In the first embodiment of the present invention of the hydraulic fracturing method that is used for the stratum, herein and hereinafter referred to as the phase I of " packing stage " relates to fracturing fluid being injected well at the sufficiently high flow velocity that Sha Mianchu produces fracturing.Carry out pumping during described packing stage, until fracture scale is enough to hold subsequently the mud in the proppant stage pumping.The volume of described filling can design (Reservoir Stimulation, 3 according to fracture design method known in the art^RdEd., M.J.Economides, K.G.Nolte, Editors, John Wiley and Sons, New York, 2000).

The water-based fracturing fluid is added with the natural or synthetic polymer for increasing fluid viscosity usually, and uses all the time in filling and driving phase subsequently.These polymer include but not limited to: guanidine that glue; The high molecular weight polysaccharide that comprises mannose and galactolipin; Or guanidine that gum derivative, for example hydroxypropyl guanidine that glue, carboxymethyl guanidine that glue, carboxy-methyl hydroxy propyl guanidine that glue.Be generally used for increasing the effective molecular weight of polymer based on the crosslinking agent of boron, titanium, zirconium or aluminium compound, thereby make it more be applicable to high temperature well.

On little degree, cellulose derivative for example hydroxyethylcellulose, hydroxypropyl cellulose and carboxymethyl hydroxyethyl cellulose is used or does not use with crosslinking agent with crosslinking agent.Xanthans has excellent support agent suspending power with being proved to be with these two biopolymers of scleroglucan, but compare with your gum derivative of guanidine more expensive, so less use.Polyacrylamide and polyacrylic acid lipopolymer and copolymer are generally used for the high temperature application scenario or lower agent as friction under low concentration in all temperature ranges.

The water-based fracturing fluid of non-polymer can utilize viscoelastic surfactant to obtain.Usually, these fluids are by mixing an amount of preparing such as the suitable surfactant such as anion, cation, nonionic and amphion (Zwiterionic).The viscosity of viscoelastic surfactant fluids is owing to the formed three-dimensional structure of the composition of fluid.When the surfactant concentration in the viscoelastic fluid significantly surpasses critical concentration, and exist electrolyte in most cases, surfactant molecule is assembled the material become vermiform for example or shaft-like micelle, and described material can interact to form has viscosity and flexible network.

Herein and hereinafter referred to as the second stage of the described method of " driving phase " relates to periodically the material of introducing solid particle or plastochondria form in the fracturing fluid, to form suspension.Driving phase is divided into two subs that periodically repeat, and " carrying sub " relates to the fracturing fluid that injection does not comprise proppant; " support sub " relates to add proppant in fracturing fluid.The result that the periodicity that contains the mud of plastochondria shape backing material is hit pressure is that proppant can not be full of the crack fully.On the contrary, isolated proppant cluster forms column, has passage between the column, and formation fluid is by this passage, as shown in Figure 2.The volume of pumping can be different when supporting sub and carrying sub.In other words, the volume that carries sub can be greater than or less than the volume that supports sub.In addition, the volume of these subs can change in time.In other words, compare with the volume of the support sub institute pumping in processing procedure later stage, but at the processing procedure support sub pumping volume still less in early stage.The relative volume of sub by the engineering staff as required supported dose of agglomerate of surface area in much cracks support and how many flaw areas be formation fluid flow freely through open channels select.

At driving phase, strengthen and/or reinforcement material is introduced in the fracturing fluid, increasing the intensity of formed proppant cluster, and prevent that them from caving in the process of closing up of cracks.Typically, reinforcement material is added to the support sub, but as hereinafter as seen is not always to need so.At whole driving phase and from a sub to another sub, the concentration of backing material and reinforcement material all can change in time.In other words, at two subs subsequently, the concentration of reinforcement material can be different.In some application scenarios of this method, at whole driving phase, namely to introduce in a continuous manner reinforcement material also be suitable carrying and support sub.In other words, the introducing of reinforcement material is not to only limit to support sub.Especially, do not change at whole driving phase, during monotone decreasing, can preferably adopt different embodiments at monotone increasing during the driving phase or during driving phase when the concentration of reinforcement material.

The proppant that is coated with resin curable or that part is curable can be used as strengthen and reinforcement material with the formation proppant cluster.Being used for the suitable proppant that is coated with resin of special bottom-hole static temperature (BHST) and the system of selection of special fracturing fluid is known by the technician.In addition, organic and/or inorfil can be strengthened proppant cluster.These materials can be used in combination with the proppant that is coated with resin or use separately.These fibers can be modified to only has adhesive coatings; Or have and be coated with the adhesive coatings that by the crack time, dissolves in the non-adhesion substance layer in the fracturing fluid.The fiber of being made by jointing material can be used as reinforcement material, and is coated with when the non-adhesion substance that is dissolved in during by the crack under subsurface temperature in the fracturing fluid.Metallic particles is another preferred version of reinforcement material, and can utilize aluminium, the steel and other metal and the alloys etc. that contain the special additive that can reduce corrosion make.Metallic particles can shaped to resemble a sphere and measure 0.1-4mm.Preferably, metallic particles employing length is 10 to 200 microns elongated shape greater than 2mm and diameter.In addition, the plate made of organic or inorganic material, pottery, metal or Metal Substrate alloy can be used as reinforcement material.These plates can be dish type or rectangle, and its length and width so that concerning all material the ratio between any two dimensions in three dimensions greater than 5:1.

Carry sub and support sub and all can comprise reagent is imported in the fracturing fluid, to increase the proppant delivery ability of fracturing fluid.In other words, reduced the sedimentation rate of proppant in fracturing fluid.Reagent can be to have length considerably beyond the material of the elongated particle of its diameter.This Effect of Materials rheological equationm of state, and the convection current in the suppression fluid, this causes the decline of the sedimentation rate of proppant in fracturing fluid.Spendable material includes organic fiber, inorfil, glass fiber, ceramic fibre, nylon fiber, carbon element and metallic fiber.The proppant delivery agent can or be decomposed in well fluids downhole at the water-based fracturing fluid, such as the fiber of making based on PLA, polyglycolic acid, polyvinyl alcohol etc.Fiber can be coated with the material that becomes viscosity under formation temperature, or is made by described material.Described fiber can be made by being coated with the jointing material that is dissolved in the non-adhesion substance in the fracturing fluid when by the crack.Greater than the main condition of 5:1, the length of employed fiber is no more than 2mm and diameter is 10-200m according to the ratio between any two dimensions in three dimensions.The weight concentration of fibrous material is 0.1 to 10% in the fracturing fluid.

When using method of the present invention, it is crucial that proppant is selected, and should select in the situation of considering increase proppant cluster intensity.Proppant cluster should keep rational residual thickness under the seam closure stress that totally cleaves.The method has increased fluid by the inflow of the open channels that forms between proppant cluster.In the case, the permeability value of proppant is not conclusive to using the method to improve well yield equally.Therefore, use in this stratum for the standard fracturing the too weak sand of particle then can successfully generate proppant cluster.The sand cost is significantly less than ceramic proppant.In addition, during the applying of closing up of cracks load, the destruction of sand grains can strengthen the strength character of the same cluster that is comprised of proppant granules.This situation be because breaking/destroying of proppant particles reduced cluster porosity, thereby the increase proppant compactness degree.Sand pump is fed into the crack and need not good particle property, the particle that does not namely need narrow diameter to distribute to produce proppant cluster.For example, in order to implement said method, can use 50 tons of sand, wherein 10 to 15 tons have 0.002 to 0.1mm particle diameter, and 15 to 30 tons have 0.2 to 0.6mm particle diameter, and 10 to 15 tons have 0.005 to 0.05mm particle diameter.It should be noted that with existing (traditional) hydraulic fracturing method, need to come in the crack that produces, to obtain similar hydraulic conductivity value for about 100 tons of proppants more expensive than sand.

For the purposes of the present invention, can preferably use the sand that only has adhesive coatings, or have and be coated with the adhesive coatings that when by the crack, dissolves in the non-adhesion substance layer in the fracturing fluid.Non-adhesion substance guarantees that adhesive support agent particle can not assemble before entering the crack, and so that moment (position) of (locating) can control proppant particles in the crack and obtain its adhesion characteristic the time.Adhesive coatings solidifies under formation temperature, and the sand particle adheres to mutually.Local laminar fluid flow is when agglomerate, and the particle of bonding reduces the proppant cluster rate of corrosion in the agglomerate, and the proppant cluster corrosion failure is minimized.

In some cases, the first embodiment of the present invention may need the phase III after the driving phase, reaches hereinafter to be called " tail-in stage " herein, and this stage relates to and imports continuously a certain amount of proppant.If the employing tail-in stage, then this stage of frac treatment similar to traditional frac treatment, in this stage the pantostrat of well-sorted conventional proppants is arranged in the crack quite near the well place.Tail-in stage can relate to importing can increase fluid the proppant delivery ability reagent and/or as the reagent of reinforcement material.Described tail-in stage and second stage difference are that well-sorted proppant namely has the roughly continuous placement of the proppant of the particle of uniform-dimension.Prevent its break (crushing) under the effect of stress that proppant strength is enough to produce when standing closing up of cracks.Task at this stage proppant is to prevent closing up of cracks, is therefore providing good fracture conductivity near the well place.The proppant that uses in this phase III should have the characteristic similar to conventional proppants.

The second embodiment

In this embodiment, hydraulic fracturing method is introduced one or more reagent and is processed in the fluid, with the formation of the proppant cluster in the crack that promotes pump period in the uninterrupted pumping proppant.When reagent reacted, it caused the part of proppant cluster to form.Usually, reagent is selected or is designed so that its reaction or function are delayed until that it is placed in the crack.The chemistry that postpones and/or physical reactions are processing methods commonly used in fracturing and many other industrial treatment.Adoptable a kind of processing method is that the simple temperature of the reagent of fracturing fluid heating is activated.For example, when surface temperature (surface temperature) when being 20 degrees centigrade, the ammonium persulfate homolysis is comparatively slow, but relatively very fast when formation temperature is 100 degrees centigrade.The second processing method is the slow dissolving of reaction reagent or cementing agent.For example, the dissolution rate of polyvinyl alcohol in water depends on its molecular weight.The encapsulation of reactive material is the common process that fracturing is adopted.By relatively non-reactive cyst membrane reaction material or reagent and fracturing fluid are separated a period of time.According to many distinct methods, the material of encapsulation is release reaction reagent subsequently or slowly or rapidly.Encapsulation can be designed to expand and break by dissolving, mechanical erosion, crushing, or only discharges its contents by slowly spreading.The example that is used for the releasing mechanism of controlled chemistry transmission all has description in many patents and document.(U.S. Patent No. 5658861; 4657784; 5716923; 5505740; 5910322).

This embodiment of the present invention relates to a plurality of steps.Carry out pumping during in the usual course, as " packing stage " of phase I of frac treatment.Above-described embodiment of liaison ground pumping is not different from proppant, and proppant (proppant) is by continuously pumping in the present embodiment.At driving phase, the concentration of proppant can increase, keep constant or decline.Usually proppant concentration is initially lower, and the slope rises near the higher concentration of processing when stopping.The crucial part of present embodiment is, at driving phase, so that the reagent of the formation of nucleation or proppant cluster is discontinuous or periodically be introduced in the fracturing fluid.Reagent only is designed to work in medium and small zone, crack or position.Backing material in this zone be affected and so that their form agglomerate, cross-over connection and become stable.In addition, the proppant that is pumped after agglomerate forms can accumulate on the agglomerate or its size is increased.

One embodiment of the present invention are to produce proppant cluster by the ability that the part reduces the transmission solid phase particles of fluid.In this case, reagent can be oxidation " gel breaker " ammonium persulfate for example of high concentration, and when diverse location place and fracturing fluid in the crack react, described gel breaker will make the local viscosity in the fracturing fluid produce violent, significant decline.When being reduced to threshold under the fluid viscosity, fracturing fluid can not transmit proppant particles, then particle stop, sedimentation and form proppant cluster.The adding of fiber has strengthened proppant cluster formation greatly.Fig. 1 has shown the critical viscosity with respect to the fracturing fluid of proppant concentration.Gel breaker with encapsulation of long release time can be used to driving phase when beginning, and the gel breaker with encapsulation of short release time can be used to driving phase when finishing.

Reinforcement material for example fiber can strengthen proppant local jams and trend of forming agglomerate between sides of fracture greatly.Therefore, in the present embodiment, aforesaid fiber and/or other reinforcement material can driving phase continuously or discontinuous be added in the fracturing fluid (with gel breaker simultaneously).

Requirement to the proppant characteristics used among the first embodiment also is applicable to the second embodiment.Can use the not narrow proppant of particle diameter distribution, namely each particle has the relatively poor proppant of sorting of the intensity level of less.For example, can be the sand particle of the similar coating of coating described in the first embodiment that has to described method.The above-mentioned phase III also can occur.

The chemical substance of crosslinking agent of boning competitively can be the reagent that reduces another type of fluid viscosity for the part.Chelating agent (with zirconate crosslinked agent reaction), D-sorbite or polyvinyl alcohol (with the borate crosslink reaction) or the part of other material of crosslinking agent deactivation is discharged to cause polymer gel to go crosslinked and significantly reduce fracturing fluid viscosity.Because many cross-linking reactions are relevant with the pH value, so the release of the part of acid or alkali also can reduce fluid viscosity.For example, the acid by introducing encapsulation and/or the adjustable control fracturing fluid of the particle pH value of material, described material is the wherein release of acid or produce PLA or polyglycolic acid with the controlled rate generation for example.Change fracturing fluid pH value and reduce the affinity that is used for forming with polymer the crosslinking agent of stable bond, and the viscosity of fluid descends for some particular polymers crosslinker composition.

For described purpose, also can use absorbent or the competitive chelating agent of the encapsulation of polymer chain crosslinking agent, it can allow controlled release.Can use the cross-linked gel chemicals for borate, for example gluconic acid sodium salt or D-sorbite.For metal crosslinking agent for example titanate or zirconates, spendable chemicals includes but not limited to EDTA, NTA, phosphate, polyvinyl acetate.Select specific chemicals well-known for the technician to attack corresponding crosslinking agent, can use for reference list of references, for example, R.M.Smith and A.E.Martell, Critical Stability Constants, 1-6 volume, Plenum publishing house, New York, 1974,1975,1976,1977,1982 and 1989.This absorbent can for example be phosphate or polyvinyl acetate.

The reagent that proppant cluster is formed by the local viscosity that reduces fracturing fluid also can be the chemical substance of the local heat exhaust that reacts to provide significantly large with fracturing fluid, and described significantly large local heat exhaust causes fracturing fluid to be heated and reduces thus its local viscosity.The reactive metal that the example of this material comprises explosive or encapsulation is sodium for example, and their each position h substances in the crack form proppant cluster with the whole length in the crack.(patent application US2004/0226715Al:Willberg, Desroches etc.).

The 3rd embodiment

The activity that the 3rd embodiment relates to by reducing proppant in the crack forms proppant cluster and the passage between them.The method relates to first and second stages similar to the second embodiment, but difference is that the reagent that agglomerate is formed reduces the activity of proppant particles.

These additives can be because the fiber bundle of the single fiber that sheds is slowly expanded and divide to mechanical agitation.The fiber bundle excluded volume (excluded volume) that increases and the part of fibre concentration increase can cause jam and produce proppant cluster.

Additive also can be by the alloy with " shape memory " characteristic make the wire of cutting.For example copper-aluminium-nickel (CuAlNi) marmem is worked in the temperature range of many oil and gas-bearing formation.These materials can be bent to be shaped spherula (spring) and under surface temperature, keep its shape.When being heated to reservoir temperature, the material with " shape memory " undergoes phase transition, and recovers the rectilinear form of its original memory thereupon.Can change phase transition temperature by changing alloying component.Preferably, introduce the material that phase transition temperature changes between each several part.When driving phase begins, for example can reasonably introduce the material of high phase transition temperature that for example has a little less than formation temperature; When second stage finishes, can reasonably introduce the material that for example has a little more than the minimum phase transition temperature of surface flow temperature.Size usually similar (K.Otsuka, C.M.Wayman, Shape memory materials, Cambridg University press, 1999 to proppant particles of spheroid with the material of " shape memory "; European patent 0360319A1; United States Patent (USP) 5040283; United States Patent (USP) 5057114; United States Patent (USP) 6752208; United States Patent (USP) 4980960; United States Patent (USP) 4619320).

When metal ball body stood rising temperature in the crack, they recovered its original-shape, and in other words described spheroid stretches.As mentioned above, the local increase of their content promotes the formation of proppant cluster in the crack effectively.Change gradually the ability of shape recovery temperature so that can form wire by changing alloying component, therefore formed equally distributed immovable proppant cluster on the whole length in crack.

The enforcement of the method in its 3rd embodiment also can stipulate to use superabsorbent material to form local jams in the fracturing fluid that flows.Superabsorbents for example cross-linked polyacrylamide Acrylate copolymer can absorb 100 to 300 times the water of their weight in water.Can obtain various superabsorbents.Can be by formation temperature, definite for the preparation of the salt content in the water of fracturing fluid etc. factor for a kind of special absorbent that this method is selected.

What this method was preferably used is the superabsorbents of being protected by housing or emulsion, and described housing or emulsion are when dissolving or distribution by being combined into of crack or the rising of fracturing fluid temperature or these conditions is current.By changing thickness of shell, the part that can control superabsorbents introduce fracturing fluid with from the time interval between the housing release.When housing dissolving or distribution, absorbing particles begins to increase by the moisture around absorbing.The quality of particle and size increase have weakened them by the movement in crack, finally cause local jams, catch proppant particles, and form proppant cluster.

In the 3rd embodiment of described method, can be plastochondria, fiber or the plate that under formation temperature its surface becomes " viscosity " for reducing the additive of the activity of proppant in the crack.Be to implement the method, can be preferably, adhesive surface is had dissolve in the additional coatings of the particle of the non-adhesion substance layer in the fracturing fluid; By changing material thickness, can change the above-mentioned time interval, along with the surperficial adhesion characteristic that passes owing to particle of described time causes forming proppant cluster.Another technology that is used for the control time interval adopts the coating that obtains adhesion characteristic under different temperatures.For using present technique, can preferably when beginning, second stage introduce the particle (therefore having the maximum temperature that demonstrates " adhesion characteristic ") with maximum protection coating layer thickness.And, can preferably when finishing, second stage correspondingly introduce the particle (therefore having the minimum temperature that demonstrates " adhesion characteristic ") with Minimal Protective coating layer thickness.When this particle entered the crack, they mutually collided (bump) and adhere to, thereby formed the aggregation of proppant particles.When aggregate size becomes characteristic width with the crack when suitable, between the described aggregation wedging fracture surface, cause local support agent jam and form proppant cluster.

As above-described embodiment of method, present embodiment also can comprise to be introduced reinforcement material in the fracturing fluid, therefore increases the intensity of the proppant cluster that forms; And introduce by means of reducing the reagent of proppant by the proppant delivery ability of the sedimentation rate increase fluid of fracturing fluid.All these requirements, particularly intensity that proppant is selected are the use of the proppant of appropriateness relatively, and (possible) wide distribution of particle size is coated with the present embodiment that still is applicable to described method at the proppant of the adhesive layer of formation condition curable in advance.The above-mentioned phase III of described method also is possible.

The 4th embodiment

The 4th embodiment of hydraulic fracturing method relate to by with the distinguishing two kinds of fluid sequence of viscosity be pumped in the well and form proppant cluster and the passage between proppant cluster.The method relates to the phase I similar to the aforementioned embodiment and proppant is introduced second stage in the given fluid continuously.

Similar with above-described embodiment, second stage may relate to reinforcement material is incorporated in the fracturing fluid, and these materials increase the intensity of the proppant cluster that forms; And the reagent of introducing the proppant delivery ability of passing through reduction proppants settle down rate enhance fluid.All these requirements, particularly intensity that proppant is selected are the use of the proppant of appropriateness relatively, the wide distribution of particle size, and the adhesive layer that is coated with in advance at the formation condition curable still is applicable to present embodiment.

The phase III of this method stops to inject fracturing fluid and other material that contains proppant, and the fluid with low-down viscosity injects the crack that produces on the contrary.Because the difference between their viscosity, after injecting higher viscosity fluid, inject low viscosity fluid and cause penetrating into higher viscosity fluid than low viscosity fluid with the form of " invader ".This forms passage in the proppant in filling crack, thereby proppant is separated into discrete agglomerate, as shown in Figure 4.In the embodiment shown in fig. 4, fluid viscosity ratio is 80.

As above-described embodiment, this method can comprise for the 4th " trailing " stage, and the material that described the 4th " trailing " stage relates to proppant, the reinforcement material that will have continuously single-size size roughly and/or has an elongated particle of the proppant delivery ability that strengthens fracturing fluid is introduced in the fluid.

Above-mentioned for fracturing and all methods with the different mechanisms that forms proppant cluster very high hydraulic fracture conductivity is provided.This can form the good strong proppant cluster generation in interval by whole length and the height in the crack.Described agglomerate is enough stable in case the crack arrest seam is closed; Passage has enough the cross section of large confession formation fluids between agglomerate.

Claims (19)

Translated fromChinese

1.一种用于地层的水力压裂的方法，包括：1. A method for hydraulic fracturing of a formation comprising:第一阶段，所述第一阶段包括将压裂流体注入井眼中，所述压裂流体含有增稠剂以在地层中产生裂缝；a first stage comprising injecting a fracturing fluid into the wellbore, the fracturing fluid containing a thickener to create fractures in the formation;第二阶段，所述第二阶段包括将支撑剂引入注入的压裂流体中以防止所产生的裂缝闭合，所述第二阶段还包括除了支撑剂之外将试剂引入压裂流体中，以便在所产生的裂缝中形成支撑剂团块和供地层流体流动的通道；以及The second stage, which includes the introduction of proppant into the injected fracturing fluid to prevent closure of the resulting fracture, said second stage also includes the introduction of reagents into the fracturing fluid in addition to the proppant, so that the Formation of proppant clusters and channels for formation fluid flow in the resulting fractures; and第三阶段，所述第三阶段包括将支撑剂连续地引入压裂流体中，所述支撑剂具有大致均匀的颗粒尺寸。A third stage, the third stage includes continuously introducing proppant into the fracturing fluid, the proppant having a substantially uniform particle size.2.如权利要求1所述的方法，其特征在于，将试剂引入压裂流体包括引入加强材料或加固材料或两者。2. The method of claim 1, wherein introducing an agent into the fracturing fluid comprises introducing a reinforcing material or a reinforcing material or both.3.如权利要求2所述的方法，其特征在于，加强材料或加固材料或两者为：有机纤维、无机纤维、或有机和无机纤维，所述纤维仅具有粘合涂层、或具有涂覆有非粘合物质层的粘合涂层，所述非粘合物质层在通过裂缝时可溶于压裂流体中；球形或细长形状的金属颗粒；在三个维度中任意两个维度之比大于5：1的有机或无机物质、陶瓷、金属或金属合金制成的板。3. The method of claim 2, wherein the reinforcing material or reinforcing material or both are: organic fibres, inorganic fibres, or organic and inorganic fibres, said fibers having only an adhesive coating, or having a coated Adhesive coating coated with a layer of non-adhesive substance that is soluble in the fracturing fluid as it passes through the fracture; spherical or elongated shaped metallic particles; in any two of three dimensions Plates made of organic or inorganic substances, ceramics, metals or metal alloys in a ratio greater than 5:1.4.如权利要求3所述的方法，其特征在于，第二阶段还涉及将另外的试剂引入压裂流体中，该试剂增强流体的支撑剂传输能力。4. The method of claim 3, wherein the second stage further involves introducing an additional agent into the fracturing fluid that enhances the proppant transport capability of the fluid.5.如权利要求4所述的方法，其特征在于，所述试剂是具有在三个维度中任意两个维度之比大于5：1的细长颗粒的材料。5. The method of claim 4, wherein the agent is a material having elongated particles in any two of three dimensions in a ratio greater than 5:1.6.如权利要求5所述的方法，其特征在于，具有细长颗粒的材料在支撑剂未被引入压裂流体中时、或连续地被引入。6. The method of claim 5, wherein the material having elongated particles is introduced while the proppant is not being introduced into the fracturing fluid, or continuously.7.如权利要求6所述的方法，其特征在于，细长颗粒是由天然形成或合成的有机材料制成的纤维、或玻璃纤维、陶瓷纤维、碳素纤维、无机或金属纤维。7. The method of claim 6, wherein the elongated particles are fibers of naturally occurring or synthetic organic materials, or glass fibres, ceramic fibres, carbon fibres, inorganic or metallic fibres.8.如权利要求7所述的方法，其特征在于，所述纤维基于聚乳酸、聚乙醇酸、聚对苯二甲酸乙二酯（PET）、它们的共聚物和聚乙烯醇制成。8. The method of claim 7, wherein said fibers are based on polylactic acid, polyglycolic acid, polyethylene terephthalate (PET), their copolymers and polyvinyl alcohol.9.如权利要求7所述的方法，其特征在于，所述纤维涂覆有在地层温度下变为粘性的材料、或由所述材料制成。9. The method of claim 7, wherein the fibers are coated with or made of a material that becomes viscous at formation temperatures.10.如权利要求7所述的方法，其特征在于，所述纤维由涂覆有非粘合物质的粘合材料制成，所述非粘合物质在通过裂缝时溶于压裂流体中。10. The method of claim 7, wherein the fibers are made of a cementitious material coated with a non-cohesive substance that dissolves in the fracturing fluid as it passes through the fracture.11.如权利要求1所述的方法，其特征在于，含有支撑剂的压裂流体的注入体积小于不含支撑剂的流体的注入体积，以产生较小的支撑剂团块、和位于支撑剂团块之间的供地层流体通过的较大通道。11. The method of claim 1, wherein the injection volume of the proppant-containing fracturing fluid is smaller than the injection volume of the fluid without proppant to produce smaller proppant clusters, and Larger channels between clusters for the passage of formation fluids.12.如权利要求1所述的方法，其特征在于，支撑剂包括具有不同颗粒直径的材料部分的混合物，每一部分中的颗粒的直径比、以及每一部分相对量被选择，以使产生的支撑剂团块或岛状体的最终孔隙最小化。12. The method of claim 1, wherein the proppant comprises a mixture of fractions of material having different particle diameters, the ratio of diameters of the particles in each fraction, and the relative amounts of each fraction selected such that the resulting propped The ultimate porosity of agent clumps or islands is minimized.13.如权利要求1所述的方法，其特征在于，支撑剂颗粒仅具有树脂涂层或粘合涂层、或者具有涂覆有非粘合物质层的树脂涂层或粘合涂层，所述非粘合物质层在通过裂缝时可溶于压裂流体中。13. The method of claim 1, wherein the proppant particles have only a resin coating or a bond coat, or have a resin coating or a bond coat coated with a layer of non-bonding substance, so The layer of non-adhesive substance is soluble in the fracturing fluid as it passes through the fracture.14.如权利要求1所述的方法，其特征在于，所述第三阶段包括将加强材料、加固材料或两者连续地引入压裂流体中。14. The method of claim 1, wherein the third stage comprises continuously introducing reinforcing material, reinforcing material, or both into the fracturing fluid.15.如权利要求14所述的方法，其特征在于，第三阶段包括将这样的材料连续地引入压裂流体中，所述材料具有增强流体的支撑剂传输能力的细长颗粒。15. The method of claim 14, wherein the third stage includes continuously introducing into the fracturing fluid a material having elongated particles that enhance the proppant transport capability of the fluid.16.一种用于地层的水力压裂的方法，包括：16. A method for hydraulic fracturing of a formation comprising:第一阶段，所述第一阶段包括将压裂流体注入井眼中，所述流体含有增稠剂，以在地层中产生裂缝；以及a first stage comprising injecting a fracturing fluid into the wellbore, the fluid containing a thickening agent, to create fractures in the formation; and第二阶段，所述第二阶段包括将支撑剂引入注入的压裂流体中以防止所产生的裂缝闭合、并还包括除了支撑剂之外将试剂引入压裂流体中以在所产生的裂缝中形成支撑剂团块和供地层流体流动的通道。The second stage, which includes introducing proppant into the injected fracturing fluid to prevent closure of the created fracture, and also includes introducing reagents into the fracturing fluid in addition to the proppant to seal in the created fracture Forms proppant clusters and channels for formation fluid flow.17.如权利要求16所述的方法，其特征在于，含有支撑剂的压裂流体的注入体积小于不含支撑剂的流体的注入体积，以产生较小的支撑剂团块、和位于支撑剂团块之间的供地层流体通过的较大通道。17. The method of claim 16, wherein the injection volume of the proppant-containing fracturing fluid is smaller than the injection volume of the fluid without proppant to produce smaller proppant clusters, and Larger channels between clusters for the passage of formation fluids.18.一种用于地层的水力压裂的方法，包括：18. A method for hydraulic fracturing of a formation comprising:第一阶段，所述第一阶段包括将压裂流体注入井眼中，所述流体含有增稠剂以产生地层裂缝；a first stage comprising injecting a fracturing fluid into the wellbore, the fluid containing a thickener to create formation fractures;第二阶段，所述第二阶段包括将支撑剂连续地引入注入的压裂流体中，以将支撑剂供送到注入的压裂流体中，从而防止所产生的裂缝闭合；以及a second stage comprising continuously introducing proppant into the injected fracturing fluid to feed the proppant into the injected fracturing fluid to prevent closure of the resulting fracture; and第三阶段，所述第三阶段包括将与压裂流体相比粘度较低的流体注入压裂流体中，所述粘度较低的流体因与压裂流体的粘度差异以将支撑剂分为离散团块的侵入物的方式渗入到压裂流体中，以在离散团块之间形成供地层流体通过的通道。The third stage, which involves injecting into the fracturing fluid a fluid with a lower viscosity than the fracturing fluid, which divides the proppant into discrete The intrusions of the clusters infiltrate into the fracturing fluid to form channels between the discrete clusters for the passage of formation fluids.19.如权利要求18所述的方法，其特征在于，含有支撑剂的压裂流体的注入体积小于不含支撑剂的流体的注入体积，以产生较小的支撑剂团块、和位于支撑剂团块之间的供地层流体通过的较大通道。19. The method of claim 18, wherein the injection volume of the proppant-containing fracturing fluid is smaller than the injection volume of the fluid without proppant to produce smaller proppant clusters, and Larger channels between clusters for the passage of formation fluids.

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