CN105874158A - Modeling of interaction of hydraulic fractures in complex fracture networks - Google Patents

Abstract

Methods of performing a fracture operation at a wellsite with a fracture network are provided. The methods involve obtaining wellsite data and a mechanical earth model, and generating a hydraulic fracture growth pattern for the fracture network over time. The generating involves extending hydraulic fractures from a wellbore and into the fracture network of a subterranean formation to form a hydraulic fracture network, determining hydraulic fracture parameters after the extending, determining transport parameters for proppant passing through the hydraulic fracture network, and determining fracture dimensions of the hydraulic fractures from the hydraulic fracture parameters, the transport parameters and the mechanical earth model. The methods also involve performing stress shadowing on the hydraulic fractures to determine stress interference between fractures at different depths, and repeating the generating based on the determined stress interference. The methods may also involve determining crossing behavior.

Description

The modeling of the interaction of hydraulically created fracture in complex fracture network

Cross-Reference to Related Applications

This application claims that it is complete in the priority of U.S. Provisional Application No. 61/900479 that on November 6th, 2013 submits to Portion's content is included in herein by reference mode at this.The application is the U. S. application the 11/th submitted on November 2nd, 2012 The part continuation application of No. 356369, entire contents is included in herein from there through reference mode.

Technical field

The disclosure relates generally to perform the method and system of well site operation.More specifically, the disclosure is directed to use In the method and system of execution fracturing operation, such as, survey subsurface formations and in subsurface formations, characterize fracturing network.

Background technology

For the ease of reclaiming Hydrocarbon from oil well and gas well, the subsurface formations surrounding these wells can be by waterpower pressure Split.Fracturing may be used for producing crack in subsurface formations to allow oil or gas to move towards well.By being specifically designed High pressure and high-velocity fluid (here referred to as " fracturing fluid " or " pressure break slurry ") by one or more wells introduce stratum And make stratum by pressure break.According to the natural stress within stratum, hydraulically created fracture can start along two contrary from well Hundreds of foot is extended in direction.In certain circumstances, they can form the fracture network of complexity.Complicated fracture network is permissible Including hydraulically created fracture and the intrinsic fracture of induction, they can along multiple azimuths in multiple planes and direction and Multiple regions intersect or does not intersects.

Current fracturing monitoring method and system can draw out position and the scope in crack that crack occurs.Some The method and system of microseism monitoring can be by using the modeled time of advent and/or ray path by earthquake time of advent It is plotted in three dimensions process seismic events position with polarization information.These method and systems may be used for speculating waterpower pressure Crack extension over time.

Can be complicated by the pattern of hydraulically created fracture produced by fracturing yield increasing and phase can be formed by The micro-seismic event closed is distributed the fracture network being marked.Complicated fracturing network has developed into and can show generation Hydraulically created fracture.United States Patent (USP)/application No.6101447, No.7363162, No.7788074, No.20080133186, No.20100138196 and No.20100250215 disclose the example of fracturing model.

Summary of the invention

At at least one aspect, it relates to the method performing fracturing operation in well site.Stratum located underground, well site is attached Closely, well runs through subsurface formations, in fracture network stratum located underground.Described fracture network has intrinsic fracture.Well site can lead to Cross to be injected in fracture network the injection fluid with proppant and be stimulated.Described method includes: obtains and includes natural splitting The well site data of the intrinsic fracture parameter of seam and the geomechanics model of acquisition subsurface formations；Generate fracture network along with time Between change hydraulically created fracture growth pattern.Described generation includes: make hydraulically created fracture extend from well and enter underground In the fracture network on stratum, to form the fracturing network including intrinsic fracture and hydraulically created fracture；Described extension it The rear hydraulic fracturing parameters determining hydraulically created fracture；Determine that proppant passes through the transmission parameter of fracturing network；And from Determined by hydraulic fracturing parameters, determined by transmit parameter and geomechanics model and determine the crack chi of hydraulically created fracture Very little.Described method is additionally included on hydraulically created fracture execution stress projection, to determine the hydraulically created fracture at different depth Between stress interfere, hydraulically created fracture performs the projection of extra stress, to determine the fracturing at different depth Stress between crack is interfered, and based on determined by stress interfere and repeat above-mentioned generation.The method can also include analyzing Stress between described hydraulically created fracture is interfered, to assess the height growth in each crack.

The projection of described execution stress can include that performing the first stress projects to determine between described hydraulically created fracture Interfere, and/or perform the second stress projection to determine the interference between the hydraulically created fracture at different depth.Described execution should Power projection can include performing the discontinuous method of two-dimension displacement and/or performing the discontinuous method of three-D displacement.

If hydraulically created fracture runs into intrinsic fracture, the method may also include based on determined by stress interfere determine water Cross characteristic between power fracturing fracture and the crack met, and this repetition can based on determined by stress interfere and intersect Characteristic repeats this generation.The method may also include and makes well in pressure break network by being injected into by the injection fluid with proppant Field volume increase.

The method can also include, if hydraulically created fracture runs into intrinsic fracture, it is determined that at the intrinsic fracture run into The cross characteristic at place, and described repeat to include based on determined by stress interfere and described cross characteristic repeats described life Become.Crack growth pattern can be changed by cross characteristic or not change.The frac pressure of fracturing network can act on by ratio The stress on crack run into is bigger, and crack growth pattern can be along the fracture propagation run into.Crack growth pattern can Persistently to extend along the crack run into until arriving the end of intrinsic fracture.Crack growth pattern can be at the end of intrinsic fracture Change direction, portion, and crack growth pattern can be in the end of intrinsic fracture along the direction extension being perpendicular to minimum stress. Crack growth pattern can be perpendicular to local principal stress extension according to stress projection.

Stress projection can include each hydraulically created fracture is performed displacement discontinuity element.Stress projection can include around well Multiple wells of field perform stress projection and use the stress performed in multiple wells projection to repeat this generation.Stress projects May be included in well and perform stress projection with multiple volume increase levels.

The method may also include checking crack growth pattern.This checking can include crack growth pattern and pressure break network At least one analog result of volume increase contrasts.The method may also include and adjusts described volume increase (example based on the projection of described stress Such as pump rate and/or fluid viscosity).

This extension can include based on the minimum stress on intrinsic fracture parameter and subsurface formations and maximum stress along crack Growth pattern extends hydraulically created fracture.Determine flaw size can include assess seismic survey, Formica fusca tracking, acoustic measurement, One in matter measurement and combinations thereof.Well site data can include geological data, petrophysical data, geomechanics number According to, at least one in log measurement data, completion data, historical data and combinations thereof.Intrinsic fracture parameter can be led to Cross observation well record by imaging, from well survey estimation flaw size, obtain one of microseism image and combinations thereof and Generate.

Accompanying drawing explanation

It is described with reference to figure below for characterizing the embodiment of the system and method for wellbore stress.In whole accompanying drawings Identical reference is used for the identical feature of labelling and parts.

Fig. 1 .1 is the schematic diagram at the fracturing scene describing fracturing operation；

Fig. 1 .2 is the schematic diagram at the fracturing scene describing to have micro-seismic event thereon；

Fig. 2 is the schematic diagram of 2D pressure break；

Fig. 3 .1 and 3.2 is the schematic diagram of stress shadow effect；

Fig. 4 is the schematic diagram compared by 2D DDM and Flac3D in two parallel straight cracks；

Fig. 5 .1-5.3 is that the crack describing to extend is at the 2D DDM of the stress of each position and Flac3D curve chart；

Fig. 6 .1-6.2 is that the crack describing two initial parallel is respectively in isotropism and anisotropic stress field The curve chart of extensions path；

Fig. 7 .1-7.2 is that the crack describing two initial offsets is respectively in isotropism and anisotropic stress field The curve chart of extensions path；

Fig. 8 is the schematic diagram in the horizontally-parallel crack along horizontal well；

Fig. 9 is the curve chart of the length describing five parallel fractures；

Figure 10 is UFM crack geometric properties and the schematic diagram of width of the parallel fracture of depiction 9；

Figure 11 .1-11.2 is to describe showing of crack geometric properties under high perforation friction condition and large fracture spacing case respectively It is intended to；

Figure 12 is to describe the figure that microseism is drawn；

Figure 13 .1-13.4 is respectively the schematic diagram of the simulation pressure break network compared with measuring with the microseism of level 1-4；

Figure 14 .1-14.4 is the schematic diagram of the pressure break network describing each grade of distribution；

Figure 15 is the flow chart describing to perform the method for fracturing operation；

Figure 16 .1-16.4 is to be depicted in the schematic diagram grown during fracturing operation around the pressure break of well；

Figure 17 is the schematic diagram that display is additional to the coordinate system of rectangle 3D DDM unit；

Figure 18-20 is for showing two vertical fractures at different depth and affecting each crack due to stress projection Height growth schematic diagram；

Figure 21 is the flow chart describing to perform another method of fracturing operation.

Detailed description of the invention

Description below includes exemplary equipment, method, technology and the instruction embodying the technology of present subject matter Sequence.It is understood, however, that the embodiment described can also be implemented when not having these concrete details.

Have been developed over the model for learning subterranean fracture network.This model it is contemplated that various factors and/or data, but It it is the mechanical interaction between Fluid Volume or crack and the fluid of injection that can consider pumping and between crack.Limit Fixed model can provide the basic comprehension to the mechanism related to, but on mathematical description, be probably complexity and/or need meter Calculation machine processes resource and time to provide the accurate simulation to fracturing extension.The model limited can be configured to perform simulation To consider change over time and the factor under desired conditions, the such as interaction between crack.

A kind of unconventional fracturing model (UFM) (or complex model) may be used for simulating and has be pre-existing in natural Complex fracture network extension in the stratum in crack.Multiple crack branches can extend and intersected with each other/staggered simultaneously.Each Open crack can apply extra stress to the rock of surrounding and adjacent crack, and this can be referred to as " stress shade " effect Should.Stress shade may cause the restriction of fracture parameter (such as, width), and this such as may cause the biggest proppant sand fallout Risk.This stress shade is also possible to change fracture propagation path and affect fracture network pattern.This stress shade can affect The modeling of the interphase interaction of fracture in complicated fracturing model.

Propose and a kind of calculate the method for stress shade in complicated fracturing network.The method can be based on having having 2D displacement discontinuity element (2D DDM) or the 3D displacement discontinuity element (3D DDM) of the enhancing that the fracture height of limit is modified are held OK.The stress field calculated by 2D DDM can be compared with 3D numerical simulation (3D DDM or flac3D), to determine The approximation of 3D crack problem.This stress shade calculates and can be integrated in UFM.The result of the simple scenario in two cracks shows Showing, position such as can be attracted one another or repel by crack according to their initial phase, and can be with independent 2D on-plane surface Fracturing model compares.May be provided for stress shade, such as, use 3D DDM, consider the crack at different depth Between interaction.

Provide the plane from the extension of many perforations bunch and the additional examples of complex fracture, demonstrate that crack interacts permissible The size of control critical eigenvalue and mode of extension.In the stratum with little stress anisotropy, owing to crack may tend to each other Repel and crack is interacted and may cause crack that huge deviating from occurs.But, even if when stress anisotropy is the biggest And the crack caused due to crack interaction turns to by limited time, and stress shade fracture width is still likely to be of impact, This may have influence on the charge velocity distributing into many perforations bunch, and thus affects whole fracture network geometric properties and support Agent is placed.

Fig. 1 .1 and 1.2 depicts the fracture propagation around well site 100.Well site has from the wellhead assembly at ground location 108 wells 104 of subsurface formations 102 extending and being placed through under it.Fracture network 106 extends around well 104.Pump system System 129 is positioned near wellhead assembly 108, is used for enabling flow through pipeline 142.

Pumping system 129 is depicted as by for recording maintenance and service data and/or holding according to the pumping arrangement specified The live operator 127 of row operation controls.Fluid is pumped into well 104 in fracturing operation by pumping system 129 from ground.

Pumping system 129 can include water source, the most multiple water pots 131, and it provides water to gel hydration unit 133.Gel water Close unit 133 and the water from tank 131 is mixed to form gel with gel.Gel is then admitted to blender 135, there with From the mixed with proppants of proppant vehicle 137, form fracturing fluid.Gel may be used for improving the viscous of fracturing fluid Property, and make proppant can be suspended in fracturing fluid.It can function as friction and reduces agent so that have less friction pressure Higher pump rate can be had in the case of power.

Fracturing fluid is then pumped into process car 120 from blender 135 by plunger displacement pump, as shown in solid line 143.Each Process car 120 receive low pressure fracturing fluid and it is under high pressure discharged into common manifold 139 (sometimes referred to as launching trolley Or emitter), as shown in dotted line 141.Fracturing fluid is then directed to well 104 by emitter 139 from processing car 120, as Shown in solid line 115.One or more process car 120 can be used to supply fracturing fluid with expected rate.

Each process car 120 generally can run with arbitrary speed, such as, transport well under its maximum working capacity OK.Run below working capacity described process car 120 can allow one of them lost efficacy and remaining is in higher speed Lower operation is to make up the absence of inefficacy pump.Computerized control system 149 can be used to manage whole during fracturing operation Individual pumping system 129.

Various fluids, the most traditional stimulation fluid with proppant, may be used to produce crack.Other fluid, Such as viscogel, " slippery water " (slick water, it can have friction and reduce thing (polymer) and water) can be used for Fracturing shale gas well.This " slippery water " can be to be thin fluids form (such as, close to the viscosity of water) and permissible For producing more complicated crack, the many microseismic fracture that such as can be detected by monitoring.

Also as shown in Fig. 1 .1 and 1.2, fracture network includes the crack on each position of being positioned at around well 104.These Crack can be the intrinsic fracture 144 having before fluid injects, or the water produced around stratum 102 in injection process Power fracturing fracture 146.Fig. 1 .2 is illustrated based on the fracture network 106 of the microseismic activity 148 using traditional method to assemble.

Multistage volume increase can be the specification of non-traditional reservoir exploitation.But, the completion in shale reservoir is optimized Obstacle potentially include lack often can correctly simulate in these stratum it is observed that the waterpower pressure of complex fracture extension Split model.Have been developed for complexity pressure break network model (or UFM) (for example, see Weng, X., Kresse, O., Wu, And Gu, H., Modeling of Hydraulic Fracture Propagation in a Naturally Fractured R. Carry in the SPE fracturing meeting in Formation.2011 24-26 in January day Texas, USA Wood Lan Zi city and exhibition The paper SPE 140253 (hereafter referred to as " Weng 2011 ") of confession；Kresse, O., Cohen, C, Weng, X, Wu, R., and Gu, H.2011 (hereafter referred to as " Kresse 2011 ") .Numerical Modeling of Hydraulic Fracturing in Naturally Fractured Formations.45th US Rock Mechanics/Geomechanics Symposium, San Francisco, CA, June 26-29, their full content is thus contained in this).

Existing model may be used for the complexity that simulation fracture extension, rock deformation and fluid produce in processing procedure Flowing in fracture network.This model may be utilized for solving the elastic change in the fluid of flowing in fracture network and crack The complete coupled problem of shape, it can have similar hypothesis and governing equation to traditional virtual 3D fracturing model.The stream of pumping The transport equation of every kind of component of body and proppant can be solved.

Traditional plane fracturing model can be modeled with the various aspects of fracture network.The UFM provided can also wrap Include the ability of interaction between simulation hydraulically created fracture and the intrinsic fracture that is pre-existing in, i.e. determine when they intersect and When extending then along intrinsic fracture, hydraulically created fracture extends through intrinsic fracture and is still captured by intrinsic fracture.Fracturing Crack can promote the development of complex fracture network with the descriscent on the cross point of intrinsic fracture.

Cross over model can from Renshaw and Pollard (for example, see Renshaw, C E. and Pollard, D.D.1995,An Experimentally Verified Criterion for Propagation across Unbounded Frictional Interfaces in Brittle,Linear Elastic Materials.Int.J.Rock Mech.Min.Sci.&Geomech.Abstr., 32:237-249 (1995), entire contents Thus it being contained in this) interface intersects standard and extends, and is applied to arbitrary intersecting angle, and can be developed (for example, see Gu, H. and Weng, X.Criterion for Fractures Crossing Frictional Interfaces at Non- orthogonal Angles.44th US Rock symposium,Salt Lake City,Utah,June 27-30,2010 (being hereafter referred to as " Gu and Weng 2010 "), entire contents is contained in this from there through reference mode) and through experiment The examination of data (for example, see, Gu, H., Weng, X., Lund, J., Mack, M., Ganguly, U. and Suarez-Rivera R.2011.Hydraulic Fracture Crossing Natural Fracture at Non-Orthogonal Angles, A Criterion, Its Validation and Applications.2011 24-26 in January day Texas, USA 5 The SPE fracturing meeting in Derain hereby city and the upper paper SPE 139984 provided of exhibition (are hereafter referred to as " Gu et Al.2011 "), entire contents is contained in this from there through reference mode), and be incorporated in UFM.

In order to correctly simulate the extension in a plurality of or complicated crack, fracturing model can consider that adjacent fracturing is split Interaction between seam branch, it is commonly referred to as " stress shade " effect.When single plane hydraulically created fracture is limited Fluid net pressure under when being opened, it can apply the stress field proportional to net pressure on rock around.

In the limiting case of endless vertical fracture with constant finite height, it is provided that by open crack institute The analytical expression of the stress field applied.For example, see Warpinski, N.F. and Teufel, L.W., Influence of Geologic Discontinuities on Hydraulic Fracture Propagation,JPT,Feb.,209-220 (1987) (hereinafter referred to as " Warpinski and Teufel ") and Warpinski, N.R., and Branagan, P.T., Altered-Stress Fracturing.SPE JPT, September, 1989,990-997 (1989), entire contents is thus It is contained in this by reference mode.Net pressure (or more accurately for producing the pressure specifying crack openings degree) can hang down Straight on the direction in crack in minimum local stress compressive stress applied above, its in fracture planes equal to net pressure, but with The increase of the distance with crack and quickly reduce.

In the distance more than a fracture height, induced stress may be the sub-fraction of net pressure.Therefore, term " stress shade " may be used for describing around the increase of stress in the region in crack.If the second hydraulically created fracture is generated as Be parallel to existing open-fractures, and if the second hydraulically created fracture fall in " stress shade " (i.e. with the most crannied Distance is less than fracture height), then the second crack actually can suffer from the closure stress more than initial original place stress.Therefore, may be used Higher pressure can be needed to carry out vee crack, and/or crack has narrower width compared with corresponding single crack.

One application of stress shade research can relate to design and optimize from horizontal hole start to extend simultaneously multiple Crack interval between crack.In the shale formation of extremely low infiltration, crack can be used for the effective of reservoir with close interval distribution Draining.But, stress shadow effect can prevent crack extend in the neighbour of another cracks (for example, see Fisher, M.K., J.R.Heinze, C.D.Harris, B.M.Davidson, C.A.Wright and K.P.Dunn, Optimizing horizontal completion techniques in the Barnett Shale using microseismic fracture The SPE90051 that mapping.2004 JIUYUE 26-29 day provides in Houston SPE technology annual meeting and exhibition, entire contents Integrally it is incorporated herein from there through reference mode).

Interference between parallel crack has been carried out studying (for example, see Warpinskiand Teufel by the past； Britt, L.K. and Smith, M.B., Horizontal Well Completion, Stimulation Optimization, The paper SPE that and Risk Mitigation.2009 JIUYUE 23-25 day Charleston city SPE Region Conference provides 125526；Cheng,Y.2009.Boundary Element Analysis of the Stress Distribution around Multiple Fractures:Implications for the Spacing of Perforation Clusters of Hydraulically Fractured Horizontal Wells.2009 JIUYUE 23-25 day Charleston The paper SPE 125769 that city's SPE Region Conference provides；Meyer, B.R. and Bazan, L.W., A Discrete Fracture Network Model for Hydraulically Induced Fractures:Theory,Parametric and Case The SPE fracturing meeting in Studies.2011 24-26 in January day Texas, USA Wood Lan Zi city and the upper offer of exhibition Paper SPE140514；Roussel, N.P. and Sharma, M.M, Optimizing Fracture Spacing and Sequencing in Horizontal-Well Fracturing, SPEPE, May, 2011, pp.173-184, entire contents It is contained in this) from there through reference mode.These researchs can include the parallel fracture under static conditions.

It is less that a kind of effect of stress shade can be that the crack in the zone line of multiple parallel fractures can have Width, this is that compressive stress due to the enhancing from neighbouring crack is (for example, see Germanovich, L.N., and Astakhov D.,Fracture Closure in Extension and Mechanical Interaction of Parallel Joints.J.Geophys.Res.,109,B02208,doi:10.1029/2002JB002131(2004)；Olson,J.E., Multi-Fracture Propagation Modeling:Applications to Hydraulic Fracturing in Shales and Tight Sands.42nd US Rock Mechanics Symposium and2nd US-Canada Rock Mechanics Symposium, San Francisco, CA, June 29-July 2,2008, entire contents passes through reference side Formula is contained in this).When multiple cracks extend simultaneously, the flow rate distribution entering crack is probably dynamic process and may be subject to Impact to the net pressure in crack.Net pressure can be highly dependent on the width in crack, and thus, stress shadow effect convection current The impact of rate distribution and flaw size requires further study.

The dynamics in the multiple cracks simultaneously extended is likely to depend on the relative position of incipient crack.If crack Be parallel, such as in the case of multiple cracks are vertical with horizontal hole, crack can repel each other, and causes crack bent outward Bent.But, if multiple crack is distributed with the pattern of engine echelon, such as from the horizontal hole being not orthogonal to fracture planes Begin crack, the interaction between adjacent slits their end can be made to attract one another and even connect (for example, see Olson,J.E.Fracture Mechanics Analysis of Joints and Veins.PhD dissertation, Stanford University,San Francisco,California(1990)；Yew,C.H.,Mear,M.E.,Chang, CC, and Zhang, X.C.On Perforating and Fracturing of Deviated Cased Wellbores.1993 Year the 68th, Houston, 3-6 in October day Texas SPE technology annual meeting and the upper paper SPE 26514 provided of exhibition；Weng, X., Fracture Initiation and Propagation from Deviated Wellbores.1993 3-6 in October Day the 68th, Houston, Texas SPE technology annual meeting and the upper paper SPE 26597 provided of exhibition, entire contents is thus It is contained in this) by reference mode.

When hydraulically created fracture intersects with secondary fracture towards different directions, its can apply on secondary fracture and The additional closure stress that net pressure is proportional.This stress can be obtained and be taken into account at the pressure dependence to fractured subterranean formation In the calculating of the crack unlatching pressure that leakage is analyzed (for example, see Nolte, K., Fracturing Pressure Analysis for nonideal behavior.JPT, Feb.1991,210-218 (SPE 20704) (1991) (are hereafter claimed Make " Nolte1991 "), entire contents is contained in this from there through reference mode).

For more complicated crack, the combination of the interaction in various crack discussed above can be there is.In order to just Really illustrate that these interact and keep computational efficiency can be attached in complex fracture network model, can build Suitably modeling framework.Method based on the 2D displacement discontinuity element (2D DDM) strengthened may be used for calculating is specifying on crack And induction stress in the rock of remaining complex fracture network (for example, see Olson, J.E., Predicting Fracture Swarms-The Influence of Sub critical Crack Growth and the Crack-Tip Process Zone on Joints Spacing in Rock.In The Initiation,Propagation and Arrest of Joints and Other Fractures, ed.J.W.Cosgrove and T.Engelder, Geological Soc.Special Publications, London, 231,73-87 (2004) (is hereafter referred to as " Olson2004 "), and they are whole Content is contained in this from there through reference mode).Crack turns to and is also based on due to stress shadow effect in extension Model is set up in the local stress direction of the change before fracture tip.Give from being combined with crack interaction modeling The analog result of UFM model.

UFM model describes

In order to simulate the extension of the complex fracture network being made up of multiple cross one another cracks, it is possible to use control pressure break The equation of the basic physics process of process.Governing equation such as can include, the fluid flowing in control critical eigenvalue network The equation of equation, control critical eigenvalue deformation and fracture propagation/interworking criterion.

Continuity equation supposes that fluid flowing extends along fracture network, has a following conservation of mass:

$\frac{\∂q}{\∂s}+\frac{\∂\left(H_{fl}\stackrel{\‾}{w}\right)}{\∂t}+q_L=0---\left(1\right)$

Wherein, q is the interior local flow rate along length of hydraulically created fracture,For crack at position s=s (x, y) place The mean breadth of cross section or opening degree, H_flFor the height of fluid, q in crack_LFor entering substrate through hydraulically created fracture wall The leakage volume fraction speed of permeable medium of surrounding (fracturing fluid penetrate into) of per unit height, it passes through Carter Leakage model is expressed.Fracture tip is as tip extension, and hydraulically created fracture is at the length quilt of any given time t It is defined as l (t).

Drive fluid characteristic can by power-law exponent ' (fluid liquidity index) and consistency index K' limit.Fluid flows Can be laminar flow, turbulent flow or the Darcy Flow through proppant fill area, and different laws correspondingly can be used to describe. For this common scenario of 1D laminar flow of the power-law fluid in any given crack branch, it is possible to use Poiseuille law (for example, see Nolte, 1991):

$\frac{\∂p}{\∂s}=-{\mathrm{\α}}_0\frac{1}{{\stackrel{\‾}{w}}^{2n^{\′}+1}}\frac{q}{H_{fl}}{\left|\frac{q}{H_{fl}}\right|}^{n^{\′}-1}---\left(2\right)$

Wherein

${\mathrm{\α}}_0=\frac{2K^{\′}}{\mathrm{\φ}{\left(n^{\′}\right)}^{n^{\′}}}\·{\left(\frac{4n^{\′}+2}{n^{\′}}\right)}^{n^{\′}};\mathrm{\φ}\left(n^{\′}\right)=\frac{1}{H_{fl}}\underset{H_{fl}}{\∫}{\left(\frac{w\left(z\right)}{\stackrel{\‾}{w}}\right)}^{\frac{2n^{\′}+1}{n^{\′}}}dz---\left(3\right)$

Here, w (z) represents fracture width, and it is the function of the degree of depth of current location s, and α is coefficient, and n' is power law index (fluid consistency index), φ is shape function, and dz is the integration increment in formula along fracture height.

Fracture width can be associated with fluid pressure by elastic equation.The elasticity of rock (its be considered homogenizing, Isotropism, linear elastomeric material) can be limited by Young's modulus E and Poisson's ratio v.For being positioned at, there is variable minimum Horizontal stress σ_h(x, y, for vertical fracture z) and in the layered medium of fluid pressure p, width characteristic (w) can be by giving The analytic solution gone out determines:

W (x, y, and z)=w (p (x, y), H, z) (4)

Wherein, W is the fracture width at the point with space coordinates x, y, z (coordinate at the center of Crack Element)；p (x, y) is fluid pressure, and H is Crack Element height, and z is at point (x, y) vertical coordinate at place along Crack Element.

Owing to the height in crack can change, governing equation group can also include such as height described in the Kresse2011 Degree increases calculating.

Except equation described above, overall volume equilibrium condition can also be met:

$\underset{0}{\overset{t}{\∫}}Q\left(t\right)dt=\underset{0}{\overset{L\left(t\right)}{\∫}}H(s,t)\stackrel{\‾}{w}(s,t)ds+\underset{H_L}{\∫}\underset{0}{\overset{t}{\∫}}\underset{0}{\overset{L\left(t\right)}{\∫}}2g_L{\mathrm{dsdtdh}}_l---\left(5\right)$

Wherein, g_LFor fluid leakage speed, Q (t) is the charge velocity with time correlation, and (s is t) that crack is in spatial point to H (x, y) place and the height at time t, ds is that dt is incremental time, dh for the length increment of integration along fracture length to s_l For leakage increment of altitude, H_LFor leakage height, s₀For spurt loss coefficient.Equation (5) represents the fluid of pumping within time t Cumulative volume equal to the fluid volume in fracture network and until time t is from the volume of crack-leakage.Here L (t) represents HFN Total length and S at time t₀For spurt loss coefficient.Boundary condition may need flow rate, net pressure and fracture width in institute Have at fracture tip is zero.

Equation group 1-5 may be used for stating one group of governing equation together with initial and boundary condition.These equations are combined And fracture network is separated into the Nonlinear System of Equations that junior unit just can form the fluid pressure p of each unit, is reduced to f P ()=0, it can use damping Newton-Raphson method to resolve.

The interaction in crack can be considered when fracturing extension in the reservoir of natural cracking is modeled. This such as includes, the interaction between hydraulically created fracture and intrinsic fracture, also the phase interaction between hydraulically created fracture With.For the interaction between hydraulically created fracture and intrinsic fracture, semi analytic Cross Criterion, example can be performed in UFM As used in the method described in Gu and Weng2010 and Gu et al.2011.

The modeling of counter stress shade

For parallel fracture, stress shade can be represented by the Stress superposition of adjacent slits.Fig. 2 is 2D crack 200 Schematic diagram about the coordinate system with x-axle and y-axle.Along each point in 2D crack, be such as positioned at the first end at h/2, Be positioned at-h/2 place the second end and intermediate point be extended to point of observation (x, y).Every line L from along 2D crack each point with Angle, θ₁、θ₂Extend to point of observation.

There is the stress field around the 2D crack of internal pressure p such as to use and retouch in Warpinski and Teufel The technology stated calculates.The stress affecting fracture width is σ_x, and can be calculated by equation below:

${\mathrm{\σ}}_x=p\[1-\frac{\stackrel{\‾}{L}}{\sqrt{{\stackrel{\‾}{L}}_1{\stackrel{\‾}{L}}_2}}\cos (\mathrm{\θ}-\frac{{\mathrm{\θ}}_1+{\mathrm{\θ}}_2}{2})-\frac{\stackrel{\‾}{L}}{{\left({\stackrel{\‾}{L}}_1{\stackrel{\‾}{L}}_2\right)}^{\frac{3}{2}}}\sin \mathrm{\θ}\sin \left(\frac{3}{2}\right({\mathrm{\θ}}_1+{\mathrm{\θ}}_2\left)\right)\]---\left(6\right)$

Wherein

$\mathrm{\θ}=\arctan (-\frac{\stackrel{\‾}{x}}{\stackrel{\‾}{y}})$

${\mathrm{\θ}}_1=\arctan (-\frac{\stackrel{\‾}{x}}{\stackrel{\‾}{1+\stackrel{\‾}{y}}})$

${\mathrm{\θ}}_2=\arctan \left(\frac{\stackrel{\‾}{x}}{1-\stackrel{\‾}{y}}\right)---\left(7\right)$

Wherein, σ_xFor the stress on x direction, p is internal pressure,L, L₁, L₂For in Fig. 2 by crack one half height The normalized coordinate of h/2 and distance.Due to σ_xY direction and x direction all change, therefore averagely should in fracture height Power can be used in the calculating of stress shade.

Analytic equation given above may be used for calculating a wherein crack and acts on putting down on adjacent parallel fracture All effective stresses and can being included in the effectively closed stress acting on this crack.

For more complicated fracture network, crack towards different directions and may intersect each other.Fig. 3 illustrates and retouches Paint the complex fracture network 300 of stress shadow effect.This fracture network 300 includes extending from well 304 and and fracture network The hydraulically created fracture 303 that another cracks 305 in 300 intersects.

A kind of more general method can be used for the crack being arbitrarily designated calculating in the remainder of fracture network Effective stress in branch.In UFM, the mechanical interaction between crack can be based on the 2D displacement discontinuity element strengthened (DDM) it is modeled (Olson 2004), is used for calculating induced stress (for example, see Fig. 3).

In 2D, plane strain, the discontinuous method of displacement (for example, see Crouch, S.L. and Starfield, A.M., Boundary Element Methods in Solid Mechanics,George Allen&Unwin Ltd, London.Fisher, M.K. (1983) (are hereafter referred to as Crouch and Starfield 1983), entire contents from there through Reference mode is contained in this), can be used for describing the opening by all slits unit acted on a Crack Element (D discontinuous with shear displacemant_DAnd D_s) normal stress that induces and shear stress (σ_nAnd σ_s).In order to illustrate due to limited crack The 3D effect highly produced, it is possible to use Olson 2004 with the correction elastic equation of following 2D DDM is in combination Affect coefficient C^ijOffer 3D modifying factor:

${\mathrm{\σ}}_n^i=\underset{j=1}{\overset{N}{\Σ}}{A}^{ij}{C}_{ns}^{ij}{D}_s^j+\underset{j=1}{\overset{N}{\Σ}}{A}^{ij}{C}_{nn}^{ij}{D}_n^j$

${\mathrm{\σ}}_s^i=\underset{j=1}{\overset{N}{\Σ}}{A}^{ij}{C}_{ss}^{ij}{D}_s^j+\underset{j=1}{\overset{N}{\Σ}}{A}^{ij}{C}_{sn}^{ij}{D}_n^j---\left(8\right)$

Wherein, A is the matrix affecting coefficient described in the equation (9), and N is to consider in its network interacted Unit sum, i is the unit considered, j=1, N are other unit in network, and they are for the impact of the stress on unit i Also calculated；Wherein C^ijFor 2D, plane strain elasticity effect coefficient.These expression formulas can be at Crouch and Starfield Find in 1983.

Elem i and j of Fig. 3 .1 schematically depict the variable i in equation (8) and j.It is applied to not connecting of Elem j Continuous D_sAnd D_nAlso describe in Fig. 3 .1.D_nCan be the same with fracture width big, and shear stress σ_sThe most permissible It is 0.The displacement of Elem j discontinuously produces stress on Elem i, such as σ_nAnd σ_sDescribed.

3D modifying factor given by Olson 2004 can be expressed as follows:

$A^{ij}=1-\frac{d_{ij}^{\mathrm{\β}}}{{\[d_{ij}^2+{(h/\mathrm{\α})}^2\]}^{\mathrm{\β}/2}}---\left(9\right)$

Wherein, h is fracture height, d_ijFor the distance between unit i and j, α and β is fitting parameter.Equation 9 illustrates that 3D repaiies When positive divisor may cause the distance between any two Crack Element to increase, interaction each other decays.

In UFM model, in each time step, the additional induction caused by stress shadow effect can be calculated Stress.Assume that at any time, fracture width is equal to Normal Displacement discontinuous quantity (D_n) and cutting at fracture faces Shearing stress is zero, i.e.σ_s ⁱ=0.The two condition is substituted into equation 8, it can be deduced that shear displacemant discontinuous quantity (D_s) With the normal stress (σ of induction on each Crack Element_n)。

The impact of the stress fracture network extension mode of stress shade induction can a point two-layer describe.First, at pressure With in width iterative process, the initial original place stress on each Crack Element can produce due to stress shadow effect by increasing Raw additional normal stress and be modified.This may directly affect fracture pressure and width distribution, thus may result in crack growth Change.Secondly, by comprising the stress (normal stress and shear stress) of stress shade induction, it is positioned at extension front, end Local influence Anlysis can also be changed, this may make local principal direction of stress from the stress direction deviation of initial original place.Should Local principal direction of stress after change can cause crack turn to from its initial extension plane and may affect further Fracture network mode of extension.

The discontinuous method of 3D displacement (3D DDM)

In addition to the 2D DDM method of enhancing disclosed herein, a kind of method based on 3D DDM may be used for various answering With.For the given fracturing network being separated into connected little rectangular element, any given rectangular element can Discontinuous to bear the displacement between two faces of the described rectangular element represented by Dx, Dy and Dz, and in rock arbitrarily A bit (x, y, induced stress z) can use 3D DDM method in this paper to calculate.

Figure 17 shows the local x of the rectangular element 1740 in an x-y plane, y, the schematic diagram 1700 of z coordinate system. The figure shows a fracture planes around coordinate axes.Described Inductive shift and stress field can be expressed as follows:

u_x=[2 (1-v) f_{, z}-zf_{, xx}]D_x-zf_{, xy}D_y-[(1-2v)f_{, x}+zf_{, xz}]D_z (10)

u_y=-zf_{, xy}D_x+[2(1-v)f_{, z}-zf_{, yy}]D_y-[(1-2v)f_{, y}+zf_{, yz}]D_z (11)

u_z=[(1-2v) f_{, x}-zf_{, xz}]D_x+[(1-2v)f_{, y}-zf_{, yz}]D_y+[2(1-v)f_{, z}-zf_{, zz}]D_z (12)

σ_xx=2G{ [2f_{, xz}-zf_{, xxx}]D_x+[2νf_{, yz}-zf_{, xxy}]D_y+[f_{, zz}+(1-2ν)f_{, yy}-zf_{, xxz}]D_z} (13)

σ_yy=2G{ [2 ν f_{, xz}-zf_{, xyy}]D_x+[2f_{, yz}-zf_{, yyy}]D_y+[f_{, zz}+(1-2ν)f_{, xx}-zf_{, yyz}]D_z} (14)

σ_zz=2G{-zf_{, xzz}D_x-zf_{, yzz}]D_y+[f_{, zz}-zf_{, xxz}]D_z} (15)

τ_Xy=2G{[(1-ν)f_{, yz}-zf_{, xxy}]D_x+[(1-ν)f_{, xz}-zf_{, xyy}]D_y-[(1-2ν)f_{, xy}+zf_{, xyz}]D_z} (16)

_τyz=2G{-[vf_{, xy}+zf_{, xyz}]D_x+[f_{, zz}+vf_{, xx}-zf_{, yyz}]D_y-zf_{, yzz}D_z} (17)

τ_Xz=2G{[(f_{, zz}+vf_{, yy}-zf_{, xxz}]D_x-[vf_{, xy}+zf_{, xyz}]D_y-zf_{, xzz}D_z} (18)

Wherein, a and b is that the half length of the rectangle length of side, Inductive shift and stress field can be expressed as:

$f(x,y,z)=\frac{1}{8\mathrm{\π}(1-\mathrm{\ν})}\underset{A}{\∫\∫}{\[{(x-\mathrm{\ξ})}^2+{(y-\mathrm{\η})}^2+z^2\]}^{-1/2}d\mathrm{\ξ}d\mathrm{\η},\left|\mathrm{\ξ}\right|\≤a,\left|\mathrm{\η}\right|\≤b---\left(19\right)$

Wherein, A is the area of square, and (x, y, z) be the coordinate system with described unit as initial point, and (ξ, η, 0) is that point is at P Coordinate, and v is Poisson's ratio.

For in three dimensions any given point of observation P (x, y, z), have productivity ratio Q (ξ, η, 0) some P (x, y, Z) induced stress at place from the stress of all slits unit by superposition and can be applied a coordinate transform and calculates.Relate to The example technique of 3D DDM is provided at Crouch, S.L. and Starfield, A.M. (1990), Boundary Element Methods in Solid Mechanics, Unwin Hyman, in London, entire contents is from there through reference mode quilt It is incorporated herein.

Interaction between the hydraulic fracture of multiple extensions or the stress shadow effect alleged at this, can affect same Depth layer or the fracture height growth in the crack of extension in different depth layer, this has shadow possibly for the success of crack treatment Ring.

In at least one embodiment in fracturing model as herein described, described model can other integrated 3D DDM surrounds the induction 3D stress field of the hydraulic fracture extended for calculating, and can be by the induced stress along vertical depth Change covers in the fracture height calculating of fracturing model.

Such as, for two parallel fractures 1811.1,1811.2 as shown by the schematic diagram 1800 in Figure 18, depend on The height of phase fracture, the growth of described height may be promoted or suppress.For the crack from different depth crack initiation, owing to hanging down Normal stress shadow effect, the existence of adjacent slits can help prevent a crack growth to by the layer shared by other cracks In.Such as, due to the interaction between the crack 1811.1,1811.2 at different depth, crack 1811.1 can to On side grow up and crack 1811.2 can grow in a downward direction, as shown by arrows.

The checking of stress shadow model

Checking for the UFM model of double-vane crack situation such as can use Weng 2011 or Kresse 2011 to enter OK.Stress shade modeling method can also be used to verify.For example, it is possible to result and the Itasca of 2D DDM will be used Consulting Group Inc.,2002,FLAC3D(FastLagrangian Analysis of Continua In3Dimensions), Version2.1, Minneapolis:ICG (2002) (being hereafter referred to as " Itasca, 2002 ") give The Flac3D gone out compares.

The contrast of 2D DDM Yu Flac3D strengthened

The 3D modifying factor that Olson 2004 proposes includes two empiricals α and β.Can be by will be to having endless The stress obtained by numerical method (the 2D DDM of enhancing) in the plane strain crack of degree and limited height obtains with by analytic method The stress obtained carries out contrasting and calibrating the value of α and β.Can be further by by having finite length and the two of height It is right that the 2DDDM result in individual straight parallel crack and the result such as using FLAC3D to carry out complete three-dimensional numerical method acquisition are carried out Compare and this model is verified.

Validation problem figure 4 illustrates.The schematic diagram 400 of Fig. 4 by be used for two straight parallel cracks enhancing 2D DDM and Flac3D contrasts.As shown in Figure 40 0, two parallel cracks 407.1,407.2 are stood along x, the stress of y-coordinate axle σ_x、σ_y.Crack is respectively provided with length 2L_xfAnd frac pressure p₁、p₂.The spacing distance in crack is s.

But crack can be modeled in Flac3D and be in same position have two tables of the mesh point being not connected with Face.Constant internal fluid pressure can be applied on grid as normal stress.Far field stress σ can also be stood in crack_xWith σ_y.Two cracks can have identical length and height, and the ratio of its camber/half length is 0.3.

Can compare along x-axle (y=0) and the stress of y-axle (x=0).Article two, the crack (s/h=0.5) of close proximity The contrast as shown in Fig. 5 .1-5.3 can be modeled into.These figures give the contrast of 2D DDM and Flac3D of expansion: along The stress contrast of x-axle (y=0) and y-axle (x=0).

These figures include curve chart 500.1,500.2,500.3 respectively, be shown respectively extension crack 2D DDM and The σ along y-axle of Flac3D_y, along the σ of y-axle_x, and the σ along x-axle_y.Fig. 5 .1 uses 2D DDM and Flac3D to draw Go out σ_yCurve chart between standardization distance (x-axle) in/p (y-axle) and distance crack.Fig. 5 .2 uses 2D DDM and Flac3D Draw out σ_xCurve chart between standardization distance (x-axle) in/p (y-axle) and distance crack.Fig. 5 .3 use 2D DDM and Flac3D draws out σ_yCurve chart between standardization distance (x-axle) in/p (y-axle) and distance crack.The position of fracture tip L_fIt is depicted as along line x/h.

As shown in Fig. 5 .1-5.3, use stress and employing that the 2D DDM method of enhancing of 3D modifying factor simulated The result that the simulation of 3D completely draws is the most identical, it means that modifying factor can obtain 3D effect in the fracture height of stress field Really.

Contrast with CSIR's O model

The UFM model of the 2D DDM method being combined with enhancing can be entered relative to complete 2D DDM simulator by CSIR O Row checking (for example, see Zhang, X., Jeffrey, R.G., and Thiercelin, M.2007.Deflection and Propagation of Fluid-Driven Fractures at Frictional Bedding Interfaces:A Numerical Investigation.Journal of Structural Geology, 29:396-410 (is hereafter referred to as " Zhang2007 "), entire contents is contained in this from there through reference mode).It is non-that this method such as may be used for crack Chang Gao, 2D DDM method cannot consider the 3D effect of fracture height this limited in the case of.

The impact of extensions path each other can be compared by the crack of two neighbouring extensions.Two initial parallel to each other The extension (along the extension of local maxima stress direction) of hydraulically created fracture can simulate for following version, example As: 1) starting point is positioned at top of each other and the most isotropically offsets；And 2) anisotropic far field stress.Crack It is right that pressure within extensions path and each crack can be carried out about the input data that table 1 is given by UFM and CSIR O coding Ratio.

Charge velocity	0.106m3/s	40bbl/min
			Stress anisotropy	0.9MPa	130psi
Young's modulus	3×10^10Pa	4.35e+6psi
			Poisson's ratio	0.35	0.35
Fluid viscosity	0.001pa·s	1cp
			Specific gravity	1.0	1.0
Minimum level stress	46.7MPa	6773psi
			Maximum horizontal stress	47.6MPa	6903psi
Crack toughness	1MPa·m0.5	1000psi/in0.5
			Fracture height	120m	394ft

Table 1 relative CSIR O model carries out the input data verified

(the flood during dx=0, dy=33ft (10.1m) of parallel to each other and starting point interval when two cracks initiate Horizontal stress field orients along x-direction), due to stress shadow effect, they may turn to and be separated from each other.

The extensions path of isotropism and anisotropic stress field is shown in Fig. 6 .1 and 6.2.These figures are to describe respectively Article two, the curve chart of the crack 609.1,609.2 of initial parallel extensions path in isotropism and anisotropic stress field 600.1、600.2.Crack 609.1 and 609.2 initial parallel ground close to decanting point 615.1,615.2, but be as they from There extends out and descriscent.Compared with isotropic situation, crack curvature in the case of stress anisotropy is depicted Cheng Geng little.This stress shadow effect being likely due to tend to make crack separated from one another with promote crack in maximum horizontal stress Competition between the far field stress of (x-direction) upper extension causes.The impact of far field stress is along with the increase of the spacing in crack And become notable, in this case, crack may tend to be parallel to direction of maximum horizontal stress extension.

Fig. 7 .1 and 7.2 depicts curve chart 700.1,700.2, it is shown that a pair respectively from two different decanting points 711.1,711.2 crack started.These illustrate when crack starts from the point that spacing distance is dx=dy=(10.1m) Contrast in isotropism and anisotropic stress field.In these figures, crack 709.1,709.2 tends towards and extends each other. The example of similar type performance is found (for example, see Zhang 2007) in laboratory research.

As noted above, the 2D DDM method of the enhancing used in UFM model is obtained in that limited fracture height Interact and the 3D effect on mode of extension in crack, be the most also efficient simultaneously.Can provide for vertical water Defeat the good assessment of the stress field splitting fracture network and fracture propagation direction (pattern).

Case

Parallel fracture in case #1 horizontal well

Fig. 8 is schematic diagram 800, it is shown that parallel cross-section crack 811.1,811.2,811.3 is respectively from around horizontal hole The multi-openings bunch 815.1,815.2,815.3 of 804 simultaneously extends.Each in crack 811.1,811.2,811.3 carries For different flow rates q₁、q₂、q₃, it is in pressure p₀Under total flow q_tA part.

When for all of crack, formation condition is the most identical with perforation, if in the well between perforation bunch Friction pressure accounting is the least, then crack is likely to be of roughly the same size.This can assume that into crack and is separated enough Remote and stress shadow effect can be left in the basket.Time in the region being located at interval at stress shadow effect between crack, crack can Can be not only impacted on width, but also impacted in another cracks size.In order to this is described, it may be considered that tool There is the simple scenario of five parallel fractures.

In this example embodiment, crack is assumed have constant height 100ft (30.5m).Being spaced apart between crack 65ft(19.8m).Other input parameter is given in Table 2.

Young's modulus	6.6×106Psi=4.55e+10Pa
		Poisson's ratio	0.35
Flow rate	12.2bbl/min=0.032m3/s
		Viscosity	300cp=0.3Pa-s
Highly	100ft=30.5m
		Leakoff coefficent	3.9×10-2m/s1/2
Stress anisotropy	200psi=1.4Mpa
		Crack interval	65ft=19.8m
The perforation quantity in each crack	100

The input parameter of table 2 case #1

For this simple scenario, it is traditionally used for Perkins-Kern-Nordgren (PKN) model of many cracks (for example, see Mack, M.G. and Warpinski, N.R., Mechanics of Hydraulic Fracturing.Chapter6,Reservoir Stimulation,3rd Ed.,eds.Economides,M.J.and Nolte, K.G.John Wiley&Sons (2000)) can calculate by combining the stress shade that equation 6 provide and be corrected. The increase of closure stress can be averaged on whole crack by the stress calculated by equation 6 and approximate.Notice this The PKN model simplified can not turn to by simulation fracture due to stress shadow effect.The result of this naive model can be with combination The UFM model having the stress shade also having crack to turn to pointwise to carry out along path, whole crack to calculate compares.

Fig. 9 illustrates the analog result of the fracture length of five cracks calculated from two kinds of models.Fig. 9 puts down for describing five Row crack is length (y-axle) curve chart 900 that (t) changes over time in injection process.Line 917.1-917.5 is UFM model Produce.Line 919.1-919.5 is that the PKN model simplified produces.

In Fig. 9, the crack geometric properties of five cracks that UFM model obtains and the profile of width figure 10 illustrates.Figure 10 For describing the schematic diagram 1000 of the crack 1021.1-1021.5 around well 1004.

Crack 1021.3 is five one in the middle of cracks, and crack 1021.1 and 1021.5 is two on limit. Owing to crack 1021.2,1021.3 and 1021.4 has less wide due to stress shadow effect than two cracks of outside Degree, therefore they are likely to be of bigger flow resistance, accommodate less flow rate, and have shorter length.Therefore, stress shade Effect the most not only affects fracture width but also affects fracture length.

Stress shadow effect can produce impact by the geometric properties of many parameter fractures.In order to illustrate these parameters In the impact of some, for change crack interval, perforation friction and stress anisotropy in the case of calculate split Seam length illustrates in table 3.

Figure 11 .1 and 11.2 illustrates and is spaced (such as, about 120ft by what UFM predicted in big perforation friction and large fracture (36.6m) the crack geometric properties in the case of).Figure 11 .1 and 11.2 is to describe the five crack 1123.1-around well 1104 The schematic diagram 1100.1 and 1100.2 of 1123.5.When perforation friction is big, using the teaching of the invention it is possible to provide equably flow rate is assigned to whole Huge metastatic capacity in perforation bunch.Therefore, it can to overcome stress shade and as shown in Figure 11 .1 consequent fracture length Approximately equal can be become.When crack interval is big, stress shadow effect can dissipate, and with the crack as shown in Figure 11 .2 There is roughly the same size.

The impact of table 3 various parameter fracture geometric properties

Case #2 complex fracture

In the example in figure 12, during UFM model can be used for simulation shale formation at the 4-level fracturing of horizontal well Reason.For example, see Cipolla, C, Weng, X., Mack, M., Ganguly, U., Kresse, O., Gu, H., Cohen, C and Wu, R.,Integrating Microseismic Mapping and Complex Fracture Modeling to Characterize Fracture Complexity.2011 24-26 in January day Texas, USA Wood Lan Zi city SPE fracturing meeting and the upper paper SPE 140185 (being hereafter referred to as " Cipolla2011 ") provided of exhibition, it is all interior Hold and be contained in this from there through reference mode.This well can by setting of casing and cement the well, and every one-level pumping by three or Four perforations bunch.Each level in four levels can comprise about 25,000bbls (4000m³) fluid and 440,000lbs (2e+6kg) proppant.Mass data can be in aboveground acquisition, including the advanced person of the estimation providing minimum and maximum horizontal stress Acoustic logging.Microseism surveying and mapping data is all available for each grade.For example, see Daniels, J., Waters, G., LeCalvez, J., Lassek, J., and Bentley, D., Contacting More of the Barnett Shale Through an Integration of Real-Time Microseismic Monitoring,Petrophysics,and The Anaheim city of Hydraulic Fracture Design.2007 12-14 in October day California, USA 2007SPE technology annual meeting and the upper paper SPE 110562 provided of exhibition.This example figure 12 illustrates.Figure 12 for describe around The microseism schema mapping of the microseismic event at different levels 1223 of well 1204.

It is each that the stress anisotropy obtained by advanced acoustic logging shows that the leading portion of well has higher stress than rear Anisotropy.Advanced 3D earthquake analysis may indicate that dominant intrinsic fracture moves towards from the NE-SW of leading portion to horizontal rear NW-SE change.For example, see Rich, J.P. and Ammerman, M., Unconventional Geophysics for City of Pittsburgh, the state non-traditional gas meeting of Unconventional Plays.2010 23-25 in February Japan-US state Pennsylvania carries The paper SPE131779 of confession, entire contents is contained in this from there through reference mode entirety.

Analog result is potentially based on UFM model and does not combine stress shade completely and calculate (for example, see Cipolla 2011), (for example, see Weng 2011) is turned to including shear stress and crack.This simulation can completely should with provided herein Power model is upgraded.Figure 13 .1-13.4 is shown respectively the fracture network 1306 around well 1304 of simulation in whole level Four Plan view, and they respectively with the contrast of microseism measurement result 1323.1-1323.4.

Analog result from Figure 13 .1-13.4 is it can be seen that for level 1 and 2, the crack of tight spacing is the most significantly Descriscent.This is possibly due to have high stress anisotropy at the leading portion of well.For level 3 and 4, stress anisotropy is relatively Low, it can be seen that due to stress shadow effect, to there is bigger descriscent, crack.

The multistage example of case #3

Case #3 is an example, it is shown that how the stress shade of prime can affect the fracturing net of next process level The mode of extension of network, all images causing the fracturing network of level Four disposition to produce changes.

This case includes that four fracturings process level.Well is by setting of casing and cements the well.Level 1 and 2 is pumped through three and penetrates Hole bunch, level 3 and 4 is pumped through four perforations bunch.Petrofabric is isotropic.Input parameter arranges in following table 4 Go out.Do not account for or consider the top view of whole fracturing network of the stress shade from prime at Figure 13 .1-13.4 Shown in.

Young's modulus	4.5×l06Psi=3.1e+10Pa
		Poisson's ratio	0.35
Flow rate	30.9bpm=0.082m3/s
		Viscosity	0.5cp=0.0005pa-s
Highly	330ft=101m
		Pump time	70min

The input parameter of table 4 case #3

Figure 14 .1-14.4 is to describe during fracturing operation the schematic diagram 1400.1-of fracture network 1429 at each grade 1400.4.Figure 14 .1 illustrates the discrete fracture network (DFN) 1429 before process.After Figure 14 .2 depicts the first process level Simulation DFN 1429.DFN 1429 have due to first process level and from its start extension hydraulically created fracture (HFN) 1431.But Figure 14 .3 illustrates and describes there is the simulation HFN1431.1-not accounting for prime impact respectively four level extensions 1431.4 DFN.Figure 14 .4 illustrates and describes to have in the extension of four levels it is contemplated that the pressure break of prime, stress shade and HFN The DFN of HFN1431.1,1431.2'-1431.4'.

When each level is separately generated, they cannot may be seen each other as shown in Figure 14 .3.When the stress of prime is cloudy When shadow and HFN are considered into as shown in Figure 14 .4, mode of extension may change.As shown in Figure 14 .3 and 14.4, the first order The hydraulically created fracture 1431.1 produced is all identical for various situations.The second level 1431.2 mode of extension may be by first The stress shade of level and the impact of new DFN (including the HFN1431.1 of level 1), cause mode of extension to be changing into HFN 1431.2'.HFN1431.1' can start to follow the HFN 1431.1 that produces in level 1, and both interdepend simultaneously.The third level 1431.3 can follow process 1431.2 in the second level, fracturing that 1431.2' produces, and due to such as 1431.3 and The stress shadow effect of the level 2 indicated by the contrast of 1431.3' is far without extending.When level 4 (1431.4) is possible, it can Can tend to being diverted away from from level 3, but the HFN of prime may be followed when its HFN 1431.3' with prime meets 1431.3' and the HFN 1431.4' being depicted as in Figure 14 .4.

A kind of method proposing stress shade for calculating in complicated fracturing network.It is right that the method can include having Enhancing 2D that limited fracture height is modified or 3D displacement discontinuity element.The method may be used for estimating in complex fracture network Interacting for solving basic 3D crack problem between different crack branches.This stress shade calculates can be in conjunction with In UFM complex fracture network.The result display crack of the simple scenario of two cracks the most both may be inhaled Draw and be likely to repel, depend on the relative position that they are initial, and can be with independent 2D on-plane surface fracturing model phase Match in excellence or beauty.

The simulation of a plurality of parallel fracture of horizontal well can be used to confirm that the crack of two ragged edges can be more significantly, and by In stress shadow effect, internal crack has the fracture length of reduction and the characteristic of width.This characteristic can also depend on Other parameters, such as perforation friction and crack interval.When crack interval is more than fracture height, stress shadow effect may dissipate And there is between many cracks unconspicuous difference.When perforation friction is big, it is provided that enough descriscents are with at perforation Flow is uniformly distributed between bunch, and despite stress shadow effect, flaw size still can become roughly the same.

When creating complex fracture, if stratum has little stress anisotropy, crack interacts and may cause splitting There is significant descriscent in seam, they trend towards repelling each other.On the other hand, for big stress anisotropy, it has been likely to be of The descriscent, crack of limit, wherein, stress anisotropy offsets the crack steering effect produced due to stress shade, and crack is forced The direction towards maximum stress is made to advance.Not considering that the amount of descriscent, crack, stress shade fracture width can have impact, it can The charge velocity being assigned in multi-openings bunch can be affected, and the region of whole fracture network covering and proppant are placed.

Figure 15 is the flow chart being depicted in the method 1500 that well site performs fracturing operation, the well site of well site e.g. Fig. 1 .1 100.Well site subsurface formations is arranged around, and stratum has the well running through it and the fracture network being located therein.Fracture network has Just like the intrinsic fracture shown in Fig. 1 .1 and 1.2.The method (1500) can include that (1580) will be by having the injection of proppant Fluid injects fracture network and performs stimulation job so that formation fracturing network increases production described well site.In some cases, This volume increase can be carried out in well site or by simulation.

The method includes that (1582) obtain well site data and the geomechanics model of subsurface formations.Well site data can include To the useful any data about well site of simulation, the intrinsic fracture parameter of such as intrinsic fracture, the image etc. of fracture network. Intrinsic fracture parameter such as can include density orientation, distribution and mechanical characteristic, and (such as coefficient of friction, cohesive force, crack are tough Degree etc.).Fracture parameters can by borehole image record is directly observed acquisition, by 3D microseism estimate, Formica fusca follow the trail of, Acoustic anisotropy, geological stratification curvature, micro-seismic event or image etc. obtain.The example of the technology obtaining fracture parameters exists Being given in PCT/US2012/48871 and US2008/0183451, their full content is contained in by reference mode at this This.

Image such as can by observe borehole image record, by well survey result estimate flaw size, obtain micro- Seismic image and/or similar approach obtain.Flaw size can by assessment seismic survey, Formica fusca tracking, acoustic measurement, Matter is measured and/or similar approach estimation.Other well site data can also by various sources (such as well site measurement, historical data, Assume) etc. generate.This data such as can include completion data, geologic structure data, petrophysical data, geomechanics number According to, log measurement data and the data of other form.Geomechanics model can obtain by using conventional art.

The method (1500) also includes that (1584) generate the hydraulically created fracture growth pattern changed over time, such as, exist During stimulation job.Figure 16 .1-16.4 depicts a kind of example (1584) generating hydraulically created fracture growth pattern.Such as figure Shown in 16.1, in its original state, the fracture network 1606.1 with intrinsic fracture 1623 is arranged around subsurface formations 1602, ground Lower stratum 1602 has the well 1604 running through it.Along with proppant is injected into subsurface formations 1602 from well 1604, from The pressure of proppant produces the hydraulically created fracture 1691 around well 1604.This hydraulically created fracture 1691 is along L₁And L₂Prolong Extend into subsurface formations (Figure 16 .2), and change runs into the another cracks in fracture network 1606.1 over time, such as figure Shown in 16.2-16.3.The point contacted with another cracks is cross point 1625.

This generation (1584) can include that (1586) make hydraulically created fracture extend from well and enter subsurface formations Fracture network includes the fracturing network of intrinsic fracture and hydraulically created fracture to be formed, as shown in Figure 16 .2.Crack growth Pattern is based on the minimum stress on intrinsic fracture parameter and subsurface formations and maximum stress.This generation also includes: (1588) determine The hydraulic fracturing parameters (such as, pressure p, width w, flow rate q etc.) of hydraulically created fracture；(1590) determine that proppant passes through waterpower The transmission parameter of pressure break network；And (1592) such as pass through determined by hydraulic fracturing parameters, determined by transmit parameter and Geomechanics model determines the flaw size (such as, highly) of fracturing.Hydraulic fracturing parameters can described extension it After determine.This determines that (1592) can also be carried out by proppant delivery parameter, well site parameter and other parameter.

This generation (1584) can include based on such as at Koutsabeloulis and Zhang, 3DReservoir Geomechanics Modeling in Oil/Gas Field Production, 9-11 day in May, 2009 is in Saudi Arabia The technical seminar of Saudi Arab region held of Arco Ba Er city and the upper paper SPE 126095 provided of exhibition, Rock behavio(u)r is modeled by the geomechanics model described in 2009SPE.This generation may also include by using as such as Well site data, fracture parameters and/or the image of the input modeling software of UFM sets up the model of fracturing operation, with at fracture network Middle generation continuous print induction hydraulically created fracture image.

The method (1500) also includes: (1594) perform stress on hydraulically created fracture and project to determine that fracturing is split Between seam, stress between (or and another cracks) is interfered, and (1598) based on stress projection and/or determined by fracturing Stress between crack is interfered and is repeated this generation (1584).This repetition can be performed to consider to affect the crack of crack growth Interfere.Stress projection can include performing such as 2D or 3D DDM and updating over time for every hydraulically created fracture and split Seam growth pattern.Crack growth pattern can be perpendicular to local principal direction of stress extension according to stress projection.Crack growth pattern Natural and hydraulically created fracture fracture network impact (see Figure 16 .3) can be included.

Multiple wells in well site can be performed stress projection.The stress projection of each well can be combined to determine to be split The interaction of seam, as determined by each well.One or more performed to in multiple wells of this generation Each stress projection can repeat.Stress projection performed by this generation volume increase to providing from multiple wells can also weigh Multiple.Execution multiple analog can also be combined in identical well with various data sets, and undesirably compare.History number According to or other data can also be imported in this generation, think that consideration in final result provides multiple information sources.

The method also includes: (1596) are if hydraulically created fracture runs into another crack, it is determined that split in fracturing Cross characteristic between seam and the crack run into, and (1598) are if hydraulically created fracture runs into a crack, then based on intersection Characteristic repeats this generation (1584) (for example, see Figure 16 .3).Cross characteristic such as can use PCT/US2012/059774's Technology determines, entire contents is incorporated herein by entirety at this.

Determine that cross characteristic can include performing stress projection.When hydraulically created fracture runs into crack, according to conditions down-hole, Crack growth pattern can be constant or change.When frac pressure is more than when acting on the stress on the crack run into, and crack is raw Long pattern can be along the fracture propagation run into.This crack growth pattern persistently can extend along the crack run into until arriving natural The end in crack.This crack growth pattern can change direction in the end of intrinsic fracture, and crack growth pattern is at intrinsic fracture End on along be perpendicular to minimum stress direction extend, as shown in Figure 16 .4.As shown in Figure 16 .4, hydraulically created fracture foundation Local stress σ₁And σ₂New path 1627 extends.

Alternatively, the method (1500) may also include (1599) checking crack growth pattern.This checking can be by obtaining Growth pattern and other data, such as microseism image as shown in Fig. 7 .1 and 7.2 contrasts and realizes.

The method can perform in any order and desirably repeat.Such as, generation step (1584)- (1599) can repeat in time, such as, be iterated by changing along with fracture network.This generation (1584) can be performed The iterative modeling performed during this generation with renewal considers interaction and the impact in multiple crack, because fracture network It is excited over time.

The method 1500 can be used for having perforation and crack (crack 811.1-811.3's the most as shown in Figure 8) Various well sites condition.In the example of fig. 8, crack 811.1-811.3 can be positioned depth about the same in stratum.One In the case of Xie, crack can be at different depths, the most as depicted in figures 18-20.

Figure 18-20 show the various illustrative diagram 1800 in parallel cross-section crack 1811.1,1811.2,1900, 2000, described parallel cross-section crack 1811.1,1811.2 multiple from around the inclined borehole 1804 stratum 1802 respectively Perforation bunch 1815.1,1815.2 simultaneously extends.Each crack 1811.1,1811.2 along landing surface 1802 respectively different deep Stratum 1817.1,1817.2,1817.3,1817.4,1817.5,1817.6 is traversed at degree D1-D6.Stratum 1802 can have various One or more stratum of composition, such as shale, sand, rock etc..This stratum 1802 has overall stress σ f, and each stratum 1817.1-1817.6 be respectively provided with corresponding stress σ f1-σ f6.

Figure 18 and 19 can use stress as above projection to produce.In the example of Figure 18, crack 1811.1 extends By stratum 1817.2-1817.4, and crack 1811.2 extends through stratum 1817.3-1817.5.In the example of Figure 19, split Seam 1811.2' extends through stratum 1817.2-1817.5.As shown in figure 19, crack can have given vertical length and prolong Stretch given distance and pass through one or more stratum, and receive from it corresponding stress effect.

In the example of Figure 19, crack 1811.1,1811.2' are not considering that what pressure projected obtains when affecting.? In this case, the height in crack 1811.1 and 1811.2' grows the most former of the stress σ f by the corresponding stratum around crack The impact of place's stress distribution.Crack 1811.1 has the vertical length L1 above perforation bunch 1815.1, and perforation bunch 1815.1 The vertical length L2 of lower section.Crack 1811.2' has the vertical length L3 above perforation bunch 1815.2, and perforation bunch 1815.2 The vertical length L4 of lower section.

Figure 20 can be produced by the stress projection of the 3D DDM of use as above.In the example of Figure 20, crack 1811.1' extends through stratum 1817.1-1817.4, and crack 1811.2 " extend through stratum 1817.3-1817.6.Figure 20 Show the sectional view once the crack affecting Figure 19 considering vertical stress projection.Crack 1811.1 is more upwards gives birth to Long, impact that crack 1811.2 projects due to stress and more downward growth.

In this case, the height growth in this crack is added the stress shade of adjacent slits by vertical original place stress distribution Impact.Crack 1811.1' has the vertical length L1' of prolongation and above perforation bunch 1815.1 below perforation bunch 1815.1 There is the vertical length L2' of reduction.Crack 1811.2 " have above perforation bunch 1815.2 reduction vertical length L3' and There is below perforation bunch 1815.2 the vertical length L4' of prolongation.Growth shown in Figure 20 reflect due to interstitial mutually The descriscent growth that effect produces, as the arrow in Figure 18 is schematically described.

Such as Figure 19-20, wherein crack is in the different degree of depth and by different stress, and the height growth in crack can be along with Relatively fracture height and change.Crack is from different stratum crack initiations, and due to vertical stress projection effect, adjacent slits Existence can help prevent a crack growth to by the stratum occupied by another crack.

Pressure as herein described projection can consider the interaction between the crack of the identical or different degree of depth.Such as at figure In 8, intermediate cracking may by its either side crack compress and as described with respect to figure 10 become less and narrower.Carry herein The UFM model of confession may be used for describing these and interacts.In another example, as depicted in figures 18-20, two cracks can be with that This mutually compresses, and is separated in crack.In this example, crack 1811.1 upwardly extends, and right side crack due to The inclination of well and grow downwards.

Figure 21 illustrates another version of method 2100, and it is it is contemplated that the impact in crack at different depth.The method 2100 can consider that no matter stress between the hydraulically created fracture of identical or different depth is interfered, and assess each crack Height growth.The method 2100 may be used for having the fracture network around it have as shown (such as at Figure 18-20) The well site of the well of network performs fracturing operation.In this version, the method 2100 can be according to previously with reference to described by Figure 15 Part or all of method 1500 perform, but there is extra stress projection 2195, the determination 1596' of amendment and repair The repetition 1598' changed.

Extra stress projection 2195 can be performed by vertical-growth based on hydraulically created fracture, deep in difference to consider The impact of the hydraulically created fracture of degree.When crack is at different depth (for example, see Figure 18-20), extra stress projection 2195 3D DDM can be used to perform.This extra stress projection 2195 can be after execution 1594 and in the determination revised Perform before 1596'.In some cases, extra stress projection 2195 can perform with performing stress projection 1594 simultaneously. Such as, when described execution 1594 is to use 3D DDM to complete, can examine in the case of there is no extra stress projection 2195 Consider the degree of depth.Time in some cases, perform 1594 and other technology can be used to complete, such as 2D DDM, and use 3D DDM The degree of depth in crack is considered in the case of having extra stress projection 2195.3D DDM can consider adjacent slits and relevant hanging down The impact of normal stress, and produce the vertical-growth after adjustment and/or length.

Determine that 1596' and repetition 1598' is modified to account extra stress projection 2195 (if executeds).Repair The determination 1596' changed includes, projects 2195 according to described execution 1594 and extra stress and determines hydraulically created fracture and institute Cross characteristic between the crack run into.The repetition 1598' of amendment includes based on 1594 identified sign interference, 2195 extra answering Power projection and 1596' determine that cross characteristic is to repeat described crack growth pattern.

Extra regulation 2197 can be based on stress projection 1594 and/or 2195 execution.Such as, by injection period (or during pressure break) regulates at least one volume increase parameter, such as pumping pressure, fluid viscosity etc., can offset crack growth.Split Seam growth can use the UFM model of the pumping parameter amendment for regulation to simulate.

One or more parts of the method, based on 1594-1599 part or all can repeat such as to perform increasing Produce operation 1580.Such as, projecting 1594 and/or 2195 based on stress, and/or the crack growth of gained, described volume increase can be by Regulate the crack growth (for example, see Figure 20) needed for obtaining.Described volume increase can be modified, such as, by regulation pumping pressure Power, fluid viscosity and/or other injection parameter, the well site operation needed for obtaining and/or required crack growth.

The some or all of various combinations of the method for Figure 15 and/or 21 can perform in various orders.

Although the disclosure is described with reference to exemplary embodiment and its executive mode, but the disclosure is not limited to Or it is not limited to these exemplary embodiments and/or executive mode.On the contrary, the system and method for the disclosure be allowed in without departing from Various amendments in the case of the spirit or scope of the disclosure, change and/or strengthen.Therefore, the disclosure is significantly by whole These amendments, change and within the scope of enhancing is included in it.

It should be noted that in the research and development of any this practical embodiments or multiple executive mode, can make concrete Judging to realize the objectives of developer, such as meeting system and be correlated with and the requirement of business association, it will be in the one side of execution Formula changes between another kind.Additionally, it should be recognized that this development efforts is probably complexity and time-consuming, but for enjoying Have the disclosure interests those of ordinary skill in the art for be conventional work.Additionally, used here as/disclosed enforcement Example also includes some key elements outside quoting.

In this specification, each numerical value should be read once (unless be readily apparent to be modified by term " about " So modify), then by again reading, unless be otherwise noted within a context with so not modifying.Equally, in this specification In, it should be understood that be listed or be described as useful, suitable any scope or the like mean to be positioned at this scope it In any and each value, include that end points is considered as having had been made by stating.Such as, " scopes from 1 to 10 " are understood For representing the possible number along the continuum between about 1 and about 10.Therefore, though the concrete data in the range of being positioned at Point, or even in the range of there is no data point, be all clearly determine or refer only to some concrete points it can be understood as Inventor is appreciated and understood that any and total data point in the range of this is considered as particularly pointing out, and inventor grasps Gamut and the whole knowledge in the range of being positioned at this.

The explanation made herein is provided solely for the information relevant to the disclosure and does not constitute prior art, and can retouch State bright some embodiments of the present invention.Herein cited is included into current all referring to file by reference mode entirety In application.

Although a small amount of exemplary embodiment is described in detail above, those skilled in the art are readily recognized that Exemplary embodiment can carry out many amendments without substantially departing from the system and method performing well stimulation job.Cause This, these whole changes are all included in as in the scope of the present disclosure of following claim restriction.In claim In book, function limitations statement is for covering the structure of the function that execution described herein is enumerated and being not only structural etc. Valency thing, but also be equivalent structures.Therefore, although nail and screw are not likely to be structural equivalents, because nail uses Wooden parts is secured together by cylinder, and screw uses helicoid, but under conditions of fixing wooden parts, nail and spiral shell Silk can be equivalent structures.Having a definite purpose of the application is that not quoting 35U.S.C. § 112 the 6th section wants right here Ask and be limited in any way, unless the most clearly by word " be used for ... device " and relevant function be used together.

Claims (24)

1. the method performing fracturing operation in well site, near stratum located underground, well site, well runs through subsurface formations, crack In network stratum located underground, described fracture network includes intrinsic fracture, and well site is by noting the injection fluid with proppant Entering and be stimulated in fracture network, described method includes:

Obtain the well site data of the intrinsic fracture parameter including intrinsic fracture and obtain the geomechanics model of subsurface formations；

Generating the hydraulically created fracture growth pattern changed over time of fracture network, described generation includes:

Make hydraulically created fracture extend from well and enter the fracture network of subsurface formations, including intrinsic fracture and water to be formed The fracturing network of power fracturing fracture；

The hydraulic fracturing parameters of hydraulically created fracture is determined after described extension；

Determine that proppant passes through the transmission parameter of fracturing network；And

Hydraulic fracturing parameters determined by from, determined by transmit parameter and geomechanics model determines splitting of hydraulically created fracture Seam size；And

Hydraulically created fracture performs stress projection, to determine that the stress between the hydraulically created fracture at different depth is done Relate to；And

Stress interference determined by based on repeats described generation.

The most the method for claim 1, wherein perform stress projection to include performing the discontinuous method of three-D displacement.

The most the method for claim 1, wherein perform stress projection to include: perform the first stress and project to determine waterpower Interference and execution the second stress between fracturing fracture project to determine doing between the hydraulically created fracture at different depth Relate to.

The most the method for claim 1, wherein perform stress projection include: perform the discontinuous method of two-dimension displacement and Perform the discontinuous method of three-D displacement.

5. the method for claim 1, also includes: if described hydraulically created fracture runs into another crack, it is determined that Cross characteristic at another crack run into, wherein, described repeat to include based on determined by stress interfere and intersect Characteristic repeats described generation.

6. method as claimed in claim 5, wherein, hydraulically created fracture growth pattern be do not changed by described cross characteristic and One in being changed by described cross characteristic.

7. method as claimed in claim 5, wherein, the frac pressure ratio of fracturing network acts on the crack run into Stress is bigger, and described crack growth pattern is along the fracture propagation run into.

The most described crack growth pattern persistently extends along the crack run into, until Reach the end of intrinsic fracture.

The most described crack growth pattern, in the change direction, end of intrinsic fracture, is split Seam growth pattern extends along the direction being perpendicular to minimum stress in the end of intrinsic fracture.

The most described crack growth pattern is perpendicular to local master according to stress projection should Power extends.

11. the most described stress projections include each hydraulically created fracture is performed displacement Discontinuous method.

12. the method for claim 1, wherein stress projection include around well site multiple wells perform stress projection And use the stress performed in the plurality of well projection to repeat described generation.

13. the most described stress projections include performing to answer with multiple volume increase levels in the wellbore Power projects.

14. the method for claim 1, also include: by by the volume increase of crack growth pattern and fracture network at least A kind of simulation carries out contrast to verify crack growth pattern.

15. the most described extensions include: based on intrinsic fracture parameter and subsurface formations Minimum stress and maximum stress make hydraulically created fracture extend along hydraulically created fracture growth pattern.

The method of claim 1, wherein 16. determine that flaw size includes: assessment seismic survey, Formica fusca are followed the trail of, sound wave One in measurement, geological survey and combinations thereof.

17. the most described well site data also include: geological data, petrophysical data, At least one in geomechanical data, log measurement data, completion data, historical data and combinations thereof.

18. the most described intrinsic fracture parameters are by observation well record by imaging, from well Estimation and Measurement flaw size, obtain one of microseism image and combinations thereof and generate.

19. 1 kinds of methods performing fracturing operation in well site, near stratum located underground, well site, well runs through subsurface formations, splits In seam network stratum located underground, described fracture network includes intrinsic fracture, and well site will be by having the injection fluid of proppant Being injected in fracture network and be stimulated, described method includes:

Obtain the well site data of the intrinsic fracture parameter including intrinsic fracture and obtain the geomechanics model of subsurface formations；

Generating the hydraulically created fracture growth pattern changed over time of fracture network, described generation includes:

Make hydraulically created fracture extend from well and enter the fracture network of subsurface formations, including intrinsic fracture and water to be formed The fracturing network of power fracturing fracture；

The hydraulic fracturing parameters of hydraulically created fracture is determined after described extension；

Determine that proppant passes through the transmission parameter of fracturing network；And

Hydraulic fracturing parameters determined by from, determined by transmit parameter and geomechanics model determines splitting of hydraulically created fracture Seam size；And

Hydraulically created fracture performs stress projection, to determine that the stress between hydraulically created fracture is interfered；

Hydraulically created fracture performs extra stress projection, to determine answering between the hydraulically created fracture at different depth Power is interfered；

If hydraulically created fracture runs into another crack, then based on determined by stress interfere and determine hydraulically created fracture and chance Cross characteristic between the crack arrived；And

Stress determined by based on is interfered and cross characteristic repeats described generation.

20. methods as claimed in claim 19, also include verifying crack growth pattern.

21. 1 kinds of methods performing fracturing operation in well site, near stratum located underground, well site, well runs through subsurface formations, splits In seam network stratum located underground, described fracture network includes that intrinsic fracture, described method include:

Well site is increased production by being injected in fracture network by the injection fluid with proppant；

Obtain the well site data of the intrinsic fracture parameter including intrinsic fracture and obtain the geomechanics model of subsurface formations；

Generating the hydraulically created fracture growth pattern changed over time of fracture network, described generation includes:

Make hydraulically created fracture extend from well and enter the fracture network of subsurface formations, including intrinsic fracture and water to be formed The fracturing network of power fracturing fracture；

The hydraulic fracturing parameters of hydraulically created fracture is determined after described extension；

Determine that proppant passes through the transmission parameter of fracturing network；And

Hydraulic fracturing parameters determined by from, determined by transmit parameter and geomechanics model determines splitting of hydraulically created fracture Seam size；And

Hydraulically created fracture performs stress projection, to determine that the stress between the hydraulically created fracture at different depth is done Relate to；And

Stress interference determined by based on repeats described generation；And

Described volume increase is regulated based on the projection of described stress.

22. methods as claimed in claim 20, also include: verify described hydraulically created fracture growth pattern.

23. methods as claimed in claim 20, also include: if hydraulically created fracture runs into another crack, it is determined that water Cross characteristic between power fracturing fracture and another crack run into, wherein, described repeat to include based on determined by stress Interfere and cross characteristic repeats described generation.

24. methods as claimed in claim 21, wherein, described regulation includes: changes and includes pump rate and fluid viscosity At least one increases production parameter.