定向射孔水力压裂平面裂缝形态数值研究
|
摘要
为了研究多分支定向射孔水力压裂裂缝扩展形态,提出基于多孔介质渗流-损伤耦合的有限元数值模拟方法,该方法的耦合原理基于Zimmerman的孔隙弹性概念,压裂准则和裂缝张开度本构关系基于损伤局部化概念,通过介质水力学属性参数的各向异性实现孔壁裂缝成核和扩展路径识别,多场耦合迭代程序基于ANSYS平台开发,模拟平面应变裂缝(KGD)在定向射孔(一字形、十字形和Y字形)条件下的裂缝扩展形态。结果表明:定向射孔条件下裂缝扩展形态复杂的原因在于,裂缝扩展同时受制于主压应力牵引作用和定向射孔导向作用,两种作用对裂缝扩展方向竞争性拉动,加上孔底部的应力集中作用,导致裂缝呈现多种扩展形态,尤其在多分支射孔条件下,射孔裂缝分支存在竞争性和共生性两种生长机制,从而进一步加剧了裂缝形态的复杂性。
In order to study the complex morphology of hydraulic fracturing under multi-oriented perforations,the finite element method(FEM) with creative points is proposed. The coupling principle is based on concepts of pore-elasticity proposed by Zimmerman's criterions of hydraulic fracturing and the constitutive relation of fracturing opening with fluid pressure is based on the concepts of damage localization. The identification of crack initiative positions and propagation path around the borehole is based on the anisotropic modeling of the fractured property parameters. The coupling program is developed on the platform of ANSYS. Through the program,the hydraulic fracture of plane strain(KGD) under the condition of oriented perforation(straight lineshaped,two-cross straight line-shaped and three lines in Y-shaped) is simulated. The results show that the reasons of complex configurations of the hydraulic fracturing lies in the traction of the maximum compressive principal stress,the steering traction of the oriented perforations,the competitive tractions on the fracture propagation and stress concentration on the bottom of the perforations. The combination of these result in all kinds of fracture configurations. Under the condition of multi-perforation,there are two growth mechanisms for the fracturing branches,i. e. the competitive and coexistence.
In order to study the complex morphology of hydraulic fracturing under multi-oriented perforations,the finite element method(FEM) with creative points is proposed. The coupling principle is based on concepts of pore-elasticity proposed by Zimmerman's criterions of hydraulic fracturing and the constitutive relation of fracturing opening with fluid pressure is based on the concepts of damage localization. The identification of crack initiative positions and propagation path around the borehole is based on the anisotropic modeling of the fractured property parameters. The coupling program is developed on the platform of ANSYS. Through the program,the hydraulic fracture of plane strain(KGD) under the condition of oriented perforation(straight lineshaped,two-cross straight line-shaped and three lines in Y-shaped) is simulated. The results show that the reasons of complex configurations of the hydraulic fracturing lies in the traction of the maximum compressive principal stress,the steering traction of the oriented perforations,the competitive tractions on the fracture propagation and stress concentration on the bottom of the perforations. The combination of these result in all kinds of fracture configurations. Under the condition of multi-perforation,there are two growth mechanisms for the fracturing branches,i. e. the competitive and coexistence.
引文
[1]姜浒,陈勉,张广清,等.定向射孔对水力裂缝起裂与延伸的影响[J].岩石力学与工程学报,2009,28(7):1321-1326.JIIANG H,CHEN M,ZHANG G Q,et al.Impact of oriented preforation on hydraulic fracture initiation and propagation[J].Chinese Journal of Rock Mechanics and Engineering,2009,28(7):1321-1326.
[2]姜浒,刘书杰,何保生,等.定向射孔对水力压裂多裂缝形态的影响实验[J].天然气工业,2014,34(2):66-70.IANG H,LIU S J,HE B S,et al.Experiments of the oriented perforating impact on the multi-fracture pattern of hydraulic fracturing treatment[J].Natural gas industry,2014,34(2):66-70.
[3]雷鑫,张士诚,许国庆,等.射孔对致密砂岩气藏水力压裂裂缝起裂与扩展的影响[J].东北石油大学学报,2015,39(2):94-113.LENG X,ZHANG S C,XU G Q,et al.Perforation of tight sandstone gas reservoir hydraulic fracturing cracks and crack and the influence of the extension[J].Journal of northeast petroleum university,2015,39(2):94-113.
[4]连志龙,张劲,吴恒安,等.水力压裂扩展的流固耦合数值模拟研究[J].岩土力学,2008,29(11):3201-3207.LIAN Z L,ZHANG J,WU H A,et al.A simulation study of hydraulic fracturing propagation with a solid-fluid coupling model[J].Rock and soil Mechanics,2008,29(11):3201-3207.
[5]李志超,李连崇,唐春安.水平井定向射孔裂缝起裂与穿层特征数值分析[J].石油与天然气地质,2015,36(3):504-510.LI Z C,LI L C,TANG C A.Numerical analysis on hydraulic fracture initiation and penetration characteristics in directionally perforated horizontal wells[J].Oil and gas geology,2015,36(3):504-510.
[6]赵熙,戴涛,鞠杨,等.储层射孔压裂裂缝起裂与扩展的数值分析[J].采矿与安全工程学报,2016,33(3):544-551.ZHANG X,DAI T,JU Y,et al.Numerical study on fracture initiation and propagation of reservoirs subjected to hydraulic perforating[J].Journal of mining and safety Engineering,2016,33(3):544-551.
[7]张广清,陈勉.定向射孔水力压裂复杂裂缝形态[J].石油勘探与开发,2009,36(1):103-108.ZHANG G Q,CHEN M.Complex fracture shapes in hydraulic fracturing with orientated perforations[J].Petroleum exploration and development,2009,36(1):103-108.
[8]ZIMMERMAN R W.Coupling in poroelasticity and thermoelasticity[J].International Journal of Rock Mechanics and Mining Sciences,2000,37:79-87.
[9]孔祥言.高等渗流力学[M].2版.合肥:中国科学技术大学出版社,2000.KONG X Y.Advanced mechanics of fluid flow in porous media[M].Second Edition.Hefei:University of science and technology of China press,2000.
[10]CHEN Z R,BUNGER A P,ZHANG X,et al.Cohesive zone finite element-based modeling of hydraulic fractures[J].Acta Mechania Solid Sinica,2009,22(5):443-452.
[11]张广明,刘合.油井水力压裂流-固耦合非线性有限元数值模拟[J].石油学报,2009,30(1):113-116.ZHANG G M,LIU H.Simulation of hydraulic fracturing of oil well based on fluid-solid coupling equation and non-linear finite element[J].Acta petrolei sinica,2009,30(1):113-116.
[12]王瀚,刘合,张劲,等.水力裂缝的缝高控制参数影响数值模拟研究[J].中国科学技术大学学报,2011,41(9):820-825.WANG H,LIU H,ZHANG J,et al.Numerical simulation of hydraulic fracture height control with different parameters[J].Journal of university of science and technology of china,2011,41(9):820-825.
[13]彪仿俊,刘合,张士诚,等.水力压裂水平裂缝影响参数的数值模拟研究[J].工程力学,2011,28(10):228-236.BIAO F J,LIU H,ZHANG S C,et al,A numerical study of parameter influences on horizontal hydraulic fracture[J].Engineering mechanics,2011,28(10):228-236.
[14]ODA M,TAKEMURA T,AOKI T.Damage growth and permeability change in triaxial compression tests of Inada granite[J].Mechanics of materials,2002,34:313-331.
[15]周创兵,熊文林.双场耦合条件下裂隙岩体的渗透张量[J].岩石力学与工程学报,1996,15:338-344.ZHOU C B,XIONG W L.Under the condition of double field coupling of fractured rock mass permeability tensor[J].Chinese Journal of Rock Mechanics and Engineering,1996,15:338-344.
[16]MENG Z P,ZHANG J C,WANG R.In-situ stress,pore pressure and stress-dependent permeability in Southern Qinshui Basin[J].International Journal of Rock Mechanics&Mining Sciences,2011,48:122-131.
[17]TSANG Y W.Usage of“Equivalent Apertures”for rock fractures as derived from hydraulic and tracer tests[J].Water Resources Res,1992,28(5):1451-1455.
[2]姜浒,刘书杰,何保生,等.定向射孔对水力压裂多裂缝形态的影响实验[J].天然气工业,2014,34(2):66-70.IANG H,LIU S J,HE B S,et al.Experiments of the oriented perforating impact on the multi-fracture pattern of hydraulic fracturing treatment[J].Natural gas industry,2014,34(2):66-70.
[3]雷鑫,张士诚,许国庆,等.射孔对致密砂岩气藏水力压裂裂缝起裂与扩展的影响[J].东北石油大学学报,2015,39(2):94-113.LENG X,ZHANG S C,XU G Q,et al.Perforation of tight sandstone gas reservoir hydraulic fracturing cracks and crack and the influence of the extension[J].Journal of northeast petroleum university,2015,39(2):94-113.
[4]连志龙,张劲,吴恒安,等.水力压裂扩展的流固耦合数值模拟研究[J].岩土力学,2008,29(11):3201-3207.LIAN Z L,ZHANG J,WU H A,et al.A simulation study of hydraulic fracturing propagation with a solid-fluid coupling model[J].Rock and soil Mechanics,2008,29(11):3201-3207.
[5]李志超,李连崇,唐春安.水平井定向射孔裂缝起裂与穿层特征数值分析[J].石油与天然气地质,2015,36(3):504-510.LI Z C,LI L C,TANG C A.Numerical analysis on hydraulic fracture initiation and penetration characteristics in directionally perforated horizontal wells[J].Oil and gas geology,2015,36(3):504-510.
[6]赵熙,戴涛,鞠杨,等.储层射孔压裂裂缝起裂与扩展的数值分析[J].采矿与安全工程学报,2016,33(3):544-551.ZHANG X,DAI T,JU Y,et al.Numerical study on fracture initiation and propagation of reservoirs subjected to hydraulic perforating[J].Journal of mining and safety Engineering,2016,33(3):544-551.
[7]张广清,陈勉.定向射孔水力压裂复杂裂缝形态[J].石油勘探与开发,2009,36(1):103-108.ZHANG G Q,CHEN M.Complex fracture shapes in hydraulic fracturing with orientated perforations[J].Petroleum exploration and development,2009,36(1):103-108.
[8]ZIMMERMAN R W.Coupling in poroelasticity and thermoelasticity[J].International Journal of Rock Mechanics and Mining Sciences,2000,37:79-87.
[9]孔祥言.高等渗流力学[M].2版.合肥:中国科学技术大学出版社,2000.KONG X Y.Advanced mechanics of fluid flow in porous media[M].Second Edition.Hefei:University of science and technology of China press,2000.
[10]CHEN Z R,BUNGER A P,ZHANG X,et al.Cohesive zone finite element-based modeling of hydraulic fractures[J].Acta Mechania Solid Sinica,2009,22(5):443-452.
[11]张广明,刘合.油井水力压裂流-固耦合非线性有限元数值模拟[J].石油学报,2009,30(1):113-116.ZHANG G M,LIU H.Simulation of hydraulic fracturing of oil well based on fluid-solid coupling equation and non-linear finite element[J].Acta petrolei sinica,2009,30(1):113-116.
[12]王瀚,刘合,张劲,等.水力裂缝的缝高控制参数影响数值模拟研究[J].中国科学技术大学学报,2011,41(9):820-825.WANG H,LIU H,ZHANG J,et al.Numerical simulation of hydraulic fracture height control with different parameters[J].Journal of university of science and technology of china,2011,41(9):820-825.
[13]彪仿俊,刘合,张士诚,等.水力压裂水平裂缝影响参数的数值模拟研究[J].工程力学,2011,28(10):228-236.BIAO F J,LIU H,ZHANG S C,et al,A numerical study of parameter influences on horizontal hydraulic fracture[J].Engineering mechanics,2011,28(10):228-236.
[14]ODA M,TAKEMURA T,AOKI T.Damage growth and permeability change in triaxial compression tests of Inada granite[J].Mechanics of materials,2002,34:313-331.
[15]周创兵,熊文林.双场耦合条件下裂隙岩体的渗透张量[J].岩石力学与工程学报,1996,15:338-344.ZHOU C B,XIONG W L.Under the condition of double field coupling of fractured rock mass permeability tensor[J].Chinese Journal of Rock Mechanics and Engineering,1996,15:338-344.
[16]MENG Z P,ZHANG J C,WANG R.In-situ stress,pore pressure and stress-dependent permeability in Southern Qinshui Basin[J].International Journal of Rock Mechanics&Mining Sciences,2011,48:122-131.
[17]TSANG Y W.Usage of“Equivalent Apertures”for rock fractures as derived from hydraulic and tracer tests[J].Water Resources Res,1992,28(5):1451-1455.