On account of difficulties in prediction of fracture network propagation caused by stimulated reservoir volume (SRV) fracturing and in simulation of coupled flow in multi-pore media in tight reservoirs, a study was conducted on fluid flow rules in tight reservoirs based on fracture propagation mechanism with SRV fracturing, a mathematical model for transient seepage flow in multiple media and a propagation model for fracture network produced by fracturing under mutual interference of multiple fractures were established, and finite element method was used for solving. A production simulation was performed based on a case study of tight oil in the Ordos Basin to analyze the contribution of different pore media to the productivity of SRV-fractured horizontal wells in tight oil reservoirs. The findings show that if the spacing of SRV-fractured horizontal well clusters is shortened, the hydraulic fracture propagation length is shorter, the average belt length is decreased, the stimulated area first is decreased and then tends to be stable, and the average belt width and fracture width first are increased and then tend to be stable; the construction to productivity of SRV-fractured horizontal well is dominated by natural and and hydraulic fractures, and the matrix has little contribution to productivity. The results of the study provide a theoretical foundation for fracture propagation simulation and productivity prediction of fractured horizontal wells in tight reservoirs.
[1] 程万,金衍,陈勉,等.页岩储层水平井分段压裂裂缝间距设计方法及影响因素分析[J].科学技术与工程, 2014, 14(15): 43-46.
CHENG Wan, JIN Yan, CHEN Mian, et al.An approach to design fracture spacing in horizontal-well multi-stage fracturing and factors analysis in shale reservoir[J].Science Technology and Engineering, 2014, 14 (15): 43-46.
[2] 周祥,张士诚,邹雨时,等.致密油藏水平井体积压裂裂缝扩展及产能模拟[J].西安石油大学学报(自然科学版), 2015,30(4):53-58.
ZHOU Xiang, ZHANG Shicheng, ZOU Yushi, et al.Simulation of fracture propagation and productivity of volume fracturing horizontal well in tight oil reservoirs[J].Journal of Xi'an Shiyou University (Natural Science), 2015, 30 (4): 53-58.
[3] HARRIS R A, SIMPSON R W.Suppression of large earthquakes by stress shadows: a comparison of Coulomb and rate-and-state failure[J].Journal of Geophysical Research Atmospheres, 1998, 1032 (B10): 24439-24452.
[4] 张后全,唐春安,贺永年,等.岩石微破裂进程的自组织临界特征探讨[J].西北地震学报, 2006, 28(1): 1-5.
ZHANG Houquan, TANG Chun'an, HE Yongnian, et al.Discussion on self-organized criticality in rock failure progress[J].Northwestern Seismological Journal, 2006, 28 (1): 1-5.
[5] CROUCH S L,STARFIELD A M.Boundary element methods in solid mechanics[M]. London: George Allen & Unwin, 1983: 704-705.
[6] OLSON J E, DAHI-TALEGHANI A.Modeling simultaneous growth of multiple hydraulic fractures and their interaction with natural fractures[C].SPE119739, 2009: 1-7.
[7] OLSON J E.Predicting fracture swarms-the influence of subcritical crack growth and the crack-tip process zone on joint spacing in rock[J].Geological Society London Special Publications, 2004, 231 (1): 73-88.
[8] 王鸿勋,张士诚.水力压裂设计数值计算方法[M].北京:石油工业出版社,1998:102-108.
WANG Hongxun, ZHANG Shicheng.Numerical calculation methods of hydraulic fracturing[M].Beijing: Petroleum Industry Press, 1998: 102-108.
[9] 李哲,杨兆中,李小刚.水力压裂模型的改进及其算法更新研究[J].天然气工业,2005, 25(1): 88-92.
LI Zhe, YANG Zhaozhong, LI Xiaogang.Improved model for hydraulic fracturing and its algorithm renewal study[J].Natural Gas Industry, 2005, 25 (1): 88-92.
[10] CARTER E D.Optimum fluid characteristics for fracture extension[M].Tulsa: American Petroleum Institute,1957:261-270.
[11] 穆龙新,赵国良,田中元,等.储层裂缝预测研究[M].北京:石油工业出版社, 2009:32-36.
MU Longxin, ZHAO Guoliang, TIAN Zhongyuan, et al.Reservoir fracture prediction[M].Beijing: Petroleum Industry Press, 2009:32-36.
[12] KARIMI-FARd M, FIROZABADI A.Numerical simulation of water injection in 2d fractured media using discrete-fracture model[C].SPE71615, 2001:1-7.
[13] 任龙,苏玉亮,郝永卯,等.基于改造模式的致密油藏体积压裂水平井动态分析[J].石油学报,2015,36(10): 1272-1279.
REN Long, SU Yuliang, HAO Yongmao, et al.Dynamic analysis of SRV-fractured horizontal wells in tight oil reservoirs based on stimulated patterns[J].Acta Petrolei Sinica,2015,36 (10): 1272-1279.
[14] RENATA D, RICE J R, LOVISON L C, et al.Stress transfer and seismic phenomena in couple subduction zones during the earthquake cycle[J].Journal of Geophysical Research Atmospheres,1988,93(B7): 7869-7884.
[15] 蒋豪,胥云,翁定为,等.水平井体积压裂基质-裂缝渗流规律分析[J].西安石油大学学报(自然科学版),2019,34(3): 49-55.
JIANG Hao, XU Yun, WENG Dingwei, et al.Analysis of seepage characteristics in matrix and fracture in volume fracturing of a horizontal well[J].Journal of Xi'an Shiyou University(Natural Science), 2019, 34 (3): 49-55.
[16] 李准,吴晓东,韩国庆,等.考虑储层应力敏感效应的体积压裂水平井瞬态压力分析[J].东北石油大学学报,2018,42(3):92-101.
LI Zhun,WU Xiaodong,HAN Guoqing,et al.Transient pressure analysis of volume fractured horizontal well with consideration of stress sensitivity[J].Journal of Northeast Petroleum University,2018,42(3):92-101.
[17] 姜瑞忠,原建伟,徐建春,等.考虑应力敏感效应的复合油藏多级压裂水平井压力动态分析[J].东北石油大学学报,2019,43(1):109-116.
JIANG Ruizhong,YUAN Jianwei,XU Jianchun,et al.Transient pressure analysis of multi-stage fracture horizontal well in composite reservoir with consideration of stress-sensitivity[J]. Journal of Northeast Petroleum University,2019,43(1):109-116.
[18] 郭建林,贾爱林,贾成业,等.页岩气水平井生产规律[J].天然气工业, 2019, 39(10): 53-58.
GUO Jianlin,JIA Ailin,JIA Chengye,et al.Production laws of shale-gas horizontal wells[J].Natural Gas Industry,2019,39(10):53-58.
[19] 梁卫卫,张亮,崔鹏兴,等.缝网压裂技术在鄂尔多斯盆地S区块特低渗透砂岩油藏水平井开发中的应用[J].石油地质与工程,2018,32(5):95-98.
LIANG Weiwei, ZHANG Liang, CUI Pengxing, et al.Application of network fracturing technique for horizontal wells of ultra-low permeability oil reservoirs in S Block, Ordos Basin[J].Petroleum Geology & Engingeering, 2018, 32 (5): 95-98.
