摘要
随着我国经济的快速发展和社会的不断进步,能源问题将会成为制约我国经济和社会快速发展的一个瓶颈,低渗透油藏的开发将会成为我国解决石油危机的一个重要方面。水力压裂技术作为提高低渗透油藏采收效果的一种重要的手段,在低渗透油藏开采中使用非常的广泛。但是这些低渗透油藏大部分是“三低”油藏(储量丰度低、渗透率低、油井产能低),这些油田主要由受岩性因素影响很大的复合性油藏构成,储油砂体多呈比较零散的窄条带状,横向岩性变化很大,渗透率很低,油水关系错综复杂,现有的水力压裂技术在应用过程中出现了各种问题,因此研究低渗透油藏的水力压力过程中出现的各种问题就迫在眉睫。
本文基于流-固耦合理论,结合渗流力学、弹塑性力学及岩石断裂、损伤力学研究了射孔参数变化、薄弱层窜层、天然裂纹和断层等几种主要影响低渗透油藏水力压裂效果的因素,通过理论分析和数值模拟计算后发现:(1)水力压裂中射孔方位角度的变化将会影响水力压裂的裂纹开裂的应力和位移;(2)水力压裂水泥环套管与岩层接触处是薄弱面,在该接触处的应力和位移产生应力奇异的现象,导致压裂液的窜层大部分发生在该处;(3)低渗透油藏中原生裂纹会影响水力压裂主裂纹的开裂和扩展,原生裂纹数量越多,则主裂纹的应力和位移将会越小;(4)当多油层同时注水压裂时,各油层裂纹的起裂和扩展将会相互影响,且隔层厚度越小,则影响越大,并且中间裂纹受到两边裂纹的影响十分明显;(5)低渗透油层中断层将会影响水力压裂的效果,断层倾斜角的改变将会影响水力压裂的速度和压力,在断层附近压裂流体的流速急剧变化,倾斜角越小,断层附近的流速也越小,而断层附近的压力梯度变化则越大。
根据以上的研究结果,可以为低渗透油层的水力压裂的压裂参数提供理论依据。
With China's rapid economic development and social progress, the energy problem will be restricting our rapid economic and social development of a bottleneck, the development of low permeability reservoir solution will become an important aspect of the oil crisis. Hydraulic fracturing of low permeability reservoirs to improve harvesting as an important means of effective, low-permeability oil reservoir in the very extensive use. But most of these low-permeability reservoirs, "three lows" reservoirs (stocks low abundance, low permeability, low oil production), mainly composed of these fields is strongly influenced by lithology factors constitute a complex of reservoirs, storage Comparison of sand scattered mostly narrow band, large lateral changes in lithology, permeability is low, water relations are complicated, the existing application of hydraulic fracturing technology in a variety of problems arising in the course, so the oil of low permeability Hydraulic pressure reservoir problems arising in the course is urgent.
Based on the fluid - solid coupling theory, mechanics, plastic and rock fracture mechanics, damage mechanics, study of the perforation parameters, the weak layer scurrying layer, natural cracks and faults and other effects of several major effect of hydraulic fracturing in low permeability reservoir factors, through theoretical analysis and numerical simulation revealed that: (1) hydraulic fracturing in the perforation orientation angle changes will affect crack initiation of hydraulic fracturing stress and displacement; (2) hydraulic fracturing cement casing contacts with the rock is that the weak side, in the contact stress and displacement generated at the stress singularity phenomenon, resulting in fracturing fluid layer channeling most of them in there; (3) low permeability reservoir of water, the native will beat crack cracking and crack main crack extension, the greater the number of primary cracks, the main crack stress and displacement will be smaller; (4) When water fracturing multiple layers simultaneously, each reservoir crack initiation and expansion of mutual influence will be , and the interlayer thickness are smaller, the greater the impact, and by the middle of the crack is very clear on both sides of the crack; (5) low-permeability reservoirs in the fault will affect the effect of hydraulic fracturing, fault inclination changes will affect the hydraulic fracturing of the velocity and pressure in the fracturing fluid flow near the fault dramatic changes, the smaller the angle, the smaller the velocity near the fault, while the pressure gradient near the fault is greater.
Based on the above findings, for hydraulic fracturing in low permeability reservoir fracturing parameters provide a theoretical basis.
引文
[1]薛炳.均匀岩层水力压裂的数值模拟及机理研究:[硕士学位论文]([Dissertation]).合肥:中国科学技术大学,2007:12-16.
[2] SI Nemat-Nasser,H.Abe,S.Hirakawa.Hydraulic fracturing and geothermal energy.MartinusNijhoff,1983,12(1):23-32.
[3]周望,谢朝阳.大庆油田水力压裂技术的发展[J].大庆石油地质开发,1998,2(17):34-37.
[4]夏惠芬,李福军.水力压裂井的生产动态预测[J].国外油田工程,1994,6(2):30-33.
[5]张景和,孙宗颀著.地应力、裂缝测试技术在石油勘探开发中的应用[M].北京:石油工业出版社,2001:36-45.
[6] Settari A.A new general model of fluid loss in hydraulic fracturing.SPE,1983,11(2):23-26.
[7] Barree R D, Mukherjee H.Determination of pressure dependent leakoff and its effect on fracture geometry. SPE 36424,1996,1(1):14-17.
[8] Economides M J,et al. Fluid—leak off delineation in high—permeability fracturing.SPEPF,1999,14(2):7-13.
[9] Yew C H,Hill A D,et a1.A study of fluid leakoff in hydraulic fracture propagation.SPE 64786,2000,1(2):24-27.
[10] James L Rodgersion. Impact of natural fractures in hydraulic fracturing of tight gas sands. SPE 59540,2000,3(5):35-38.
[11]王鸿勋,衣同春.利用幂律液体压裂时水平裂缝几何尺寸的数值计算方法[J].石油学报,1985,(4):25-28.
[12]张建华,胡启,刘振华.钻井泥浆滤液侵^储集层的理论计算模型[J].石油学报,1991,15(4):73-78.
[13]付永强,郭建春,赵金洲等.一种多参数的压裂液在双重介质中滤失模型的推导与计算[J].天然气工业,2003,23(3):88-93.
[14] J.H.Hartsock & J.E.Warren. The effect of horizontal hydraulic fracturing on well performance.JPT,1961,1(2):1050-1057.
[15] A.C.Gringarten & H.J.Ramey Jr. Unsteady-state pressure distributions created by a well with a single horizontal fracture, partial penetration, or restricted entry.SPEJ,1974,1(3):10-15.
[16] W.Sung and T.Ertekin. Performance comparison of vertical and horizontal hydraulic fractures and horizontal boreholes in low permezbility reservoirs. A numerical study. SPE/DOE,1987,1(1):185-193.
[17]衣同春,王鸿勋.水平裂缝压裂参数优选[J].石油钻采工艺,1989,3(3):15-19.
[18]魏明臻.大庆油田密井网裂缝参数优化:[硕士学位论文]([Dissertation]).大庆:大庆石油学院,1996:26-45.
[19]王鸿勋,张士诚著.水力压裂设计数值计算方法[M].北京:石油工业出版社,1998:45-90.
[20] Hanson.A.W.and Lyons.D.W. Method of fracturing formations.U.S. Patent 3151678,1964,2(1):36-45.
[21] Arp.M.E.and Hilton.R.E.Case history study of fracture height containment in east texas.SPE14653,1986,1(5):17-24.
[22] Mukherjee.H et al.Successful Control of Fracture Height Growth by Placement of Artificial Barrier.SPE25917,1993,2(2):36-39.
[23] Morales.R.etal.Production optimization by an artificial control of fracture height growth.SPE38150,1997,1(3):89-94.
[24]李宾元.裂缝中垂直裂缝高度的讨论.石油钻采工艺,1984,5(7):43-48.
[25]胡永全,任书泉.水力压裂裂缝高度控制分析.大庆石油地质与开发,1996,15(2):55-58.
[26]陈治喜,陈勉,沈忠厚.层状介质中水力裂缝的垂向扩展.石油大学学报(自然科学版),1997,21(4):23-26.
[27] Howard,G.C.and Clark,J.B.Factors to be considered in obtaining proper cementing of casing Drilling and Production Practices, API,1948,1(3):257-272
[28] Parker,P.N,Ladd,B.J.Ross,W.M and Wahl.w.W.An evaluation of a primary cementing technique using low displacement rates,SPE1234.Presented at the 40th Annual Meeting of SPE,1965,6(2):3-6.
[29]王华芬,屈中英.王庄变质岩油藏[M].北京:石油工业出版社,1997:1-24.
[30]伍友佳,李建,赵明等.裂缝水窜形成的剩余油研究[J],西南石油大学学报2009,29(3):36-38.
[31]杨万有.薄差层压裂力学机理及工艺研究[:硕士学位论文][(Dissertation]).大庆:大庆石油学院,2006:22-26.
[32]于丹.柴北缘断裂构造特征及封闭性评价[:硕士学位论文][(Dissertation]).大庆:大庆石油学院,2007:18-25.
[33]王文红.大庆油田薄、差油层射孔完井工艺技术研究:[硕士学位论文]([Dissertation]).大庆:大庆石油学院,2006:9-20.
[34]刘永喜.大庆油田薄差层压裂工艺技术研究:[硕士学位论文]([Dissertation]).大庆:大庆石油学院,2007:6-20.
[35]徐芝纶.弹性力学简明教程[M].北京:高等教育出版社,2002:149-152.
[36]纪佑军.渗流诱发套损机理及数值模拟研究:[硕士学位论文]([Dissertation]).武汉:武汉工业学院,2007:21-45.
[37]尹祥础,修济刚译.岩石断裂力学[M].北京:地震出版社,1992:23-36.
[38]张广明.水平井水力压裂数值模拟研究: [博士学位论文]([Dissertation]).合肥:中国科技大学,2010:23-60.
[39]薛炳.均匀岩层水力压裂的数值模拟及机理研究:[硕士学位论文]([Dissertation]).合肥:中国科技大学,2007:45-54.
[40]孔祥言.高等渗流力学[M].合肥:中国科学技术大学出版社,2010:676-679
[41]刘予东.射孔参数对压裂裂缝的影响:[硕士学位论文]([Dissertation]).西安:西安石油大学,2006:21-24.
[42]连志龙.水力压裂扩展的流固耦合数值模拟研究:[博士学位论文]([Dissertation]).合肥:中国科技大学,2007:89-96.
[43]沈志宏,辉强,伍尚继等.薄油层薄隔层活跃水层调整井固井技术[J].石油钻井工艺,2001,2(32):25-26.
[44]黄海.浅层稠油油藏水窜的研究[J].内蒙古石油化工,2007,10(2):90-91.
[45]李勇明,赵金洲,郭建春.天然裂缝性储层压裂液滤失的数值模拟研究[J].钻井液与完井液,2004,21(1):20-22.
[46]张玉林.大庆西部外围特低渗透油田开发技术研究:[硕士学位论文]([Dissertation]).大庆:大庆石油学院,2002:6-16.
[47]傅宇方,梁正召.岩石介质细观非均匀性对宏观破裂过程的影响[J].岩土工程学报,2000,22(6):705-710.
[48] D.B.van Dam. Impact of Rock Plasticity Oil Hydraulic Fracture Propagation and Closure. SPE78812,2002,8(1):16-26.
[49] S.C.Maxwell.T.I.Urbancic.ESG.Microseismic Imaging ofHydraulic Fracture Complexity in the Barnett Shale.SPE,2002,7(2):68-75.
[50] Blot M.A,Mechanics of deformation and acoustic propagation in porous medial J.Appl.Phys,1962,13(1):14-18.
[51]刘建军,冯夏庭,裴桂红.水力压裂三维数学模型研究[J].岩石力学与工程学报, 2003,22(12):2042-2046.
[52]黎水泉,徐秉业.双重介质裂缝型油气藏油水两相流动与固体变形耦合数学模型[J].天然气工业,1999,19(4):43-45.
[53]程兆慧,罗英俊.中深井油层水力压裂[M].北京:石油工业出版社,1990:35-68.
[54]杨秀夫.三维水力压裂的数值模拟研究:[博士学位论文]([Dissertation]).北京:中国石油大学,1998:23-56.
[55]刘建军,杜广林,薛强.水力压裂的连续损伤模型初探[J].机械强度,2004,26(1):134-137.
[56]谢朝阳,李志,罗美娥.大庆油田薄差油层压裂挖潜技术[J].断块油气田,1997,7(4):15-19.