深层页岩地层断层较为发育,附近地应力场呈现非均匀分布,水力压裂产生的裂缝可能出现非平面、非对称、非规则延伸行为,进而影响压裂缝网体积。针对该问题,以川南区块Y101井区实际断层为例,构建了深层页岩气复杂构造内断层附近非均匀应力场表征模型与压裂缝网扩展模型,分析了断层特征参数对地应力的影响,并定量研究了断层类型、断距、长度、高度、走向、倾角和距离对压裂缝网体积的影响。结果表明:断层的断距、长度和高度越大,地应力偏转角和地应力差越大,压裂缝网体积越小;断层的倾角和远离断层的距离越大,地应力偏转角和地应力差越小,压裂缝网体积越大;断层的走向越大,地应力偏转角越大,地应力差越小,压裂缝网体积越大。断层参数对缝网体积的影响程度由大到小依次为倾角、走向、断距、距离、高度、长度。该研究可为深层页岩复杂构造下的缝网压裂优化设计提供理论依据。
Deep shale formation faults are relatively developed, and the nearby geostress field presents non-uniform distribution. The fractures generated by hydraulic fracturing may propagate non-planarly, asymmetrically and irregularly, which further affects the volume of fracture network. To address this problem, taking the actual fault in Well Y101, South Sichuan Block as an example, a non-uniform stress field characterization model and a compression fracture network expansion model of the faults in the complex deep shale gas formation were established to analyze the influence of fault characteristic parameters on the ground stress, and to quantitatively study the influence of fault type, fault distance, length, height, strike, dip angle and distance on the fracture network volume. The results show that the larger the displacement, length and height of the fault, the greater the geostress deflection angle and geostress difference, and the smaller the volume of fracturing fracture network. The larger the dip angle of the fault and the distance away from the fault, the smaller the geostress deflection angle and geostress difference, and the bigger the volume of fracturing fracture network. The larger the strike of fault, the greater the geostress deflection angle, the smaller the geostress difference, and the bigger the volume of fracturing fracture network. The influence degree of the following fault parameters on the volume of fracture network is in descending order: dip angle, strike, fault displacement, distance, height and length. The study can provide a theoretical basis for the optimization design of fracturing fracture network under the complex structure of deep shale.
[1] 赵金洲,任岚,蒋廷学,等.中国页岩气压裂十年:回顾与展望[J].天然气工业,2021,41(8):121-142.
ZHAO Jinzhou,REN Lan,JIANG Tingxue,et al.Ten years of gas shale fracturing in China:review and prospect[J].Natural Gas Industry,2021,41(8):121-142.
[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.
JIANG Hu,LIU Shujie,HE Baosheng,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] LIN B,JIN Y,CHEN Y.Prediction of in-situ stresses and pore pressure in a shale gas reservoir subject to finite fault slip[C].SPE191919,2018:1-20.
[4] 倪伟,刘桂玲,林波.复合断层对地应力的影响研究[J].复杂油气藏,2018,11(4):38-41.
NI Wei,LIU Guiling,LIN Bo.Study on the influence of composite faults on ground stress[J].Complex Hydrocarbon Reservoirs,2018,11(4):38-41.
[5] FIGUEIREDO B,TSANG C F,RUTQVIST J,et al.Study of hydraulic fracturing processes in shale formations with complex geological settings[J].Journal of Petroleum Science and Engineering,2017,152:361-374.
[6] 程万,金衍,陈勉,等.三维空间中非连续面对水力压裂影响的试验研究[J].岩土工程学报,2015,37(3):559-563.
CHENG Wan,JIN Yan,CHEN Mian,et al.Experimental investigation on influence of discontinuities on hydraulic fracture propagation in three-dimensional space[J].Chinese Journal of Geotechnical Engineering,2015,37(3):559-563.
[7] 刘尧文,廖如刚,张远,等.涪陵页岩气田井地联合微地震监测气藏实例及应用[J].天然气工业,2016,36(10):56-62.
LIU Yaowen,LIAO Rugang,ZHANG Yuan,et al.Application of surface-downhole combined microseismic monitoring technology in the Fuling shale gas field and its enlightenment[J].Natural Gas Industry,2016,36(10):56-62.
[8] ASTAKHOV D,ROADARMEL W,NANAYAKKARA A.A new method of characterizing the stimulated reservoir volume using tiltmeter-based surface microdeformation measurements[C].SPE151017-MS,2012:1-15.
[9] YU Guang,AGUILERA R.3D analytical modeling of hydraulic fracturing stimulated reservoir volume[C].SPE153486-MS,2012:1-17.
[10] WU Kan,OLSON J E.Investigation of the impact of fracture spacing and fluid properties for interfering simultaneously or sequentially generated hydraulic fractures[J].SPE Production & Operations,2013,28(4):427-436.
[11] CROUCH S L.Solution of plane elasticity problems by the displacement discontinuity method.I.infinite body solution[J].International Journal for Numerical Methods in Engineering,1976,10(2):301-343.
[12] REN Lan,LIN Ran,ZHAO Jinzhou,et al.Stimulated reservoir volume estimation for shale gas fracturing:mechanism and modeling approach[J].Journal of Petroleum Science and Engineering,2018,166:290-304.
[13] CROUCH S L,STARFIELD A M.Boundary element methods in solid mechanics[M].London:George Allen & Unwin,1983:1-58.
[14] ERDOGAN F,SIH G C.On the crack extension in plates under plane loading and transverse shear[J].Journal of Basic Engineering,1963,85(4):519-525.
[15] OLSON J E.Fracture aperture,length and pattern geometry development under biaxial loading:a numerical study with applications to natural,cross-jointed systems[J].Geological Society,2007,289(1):123-142.
[16] WENG X,SESETTY V,KRESSE O.Investigation of shear-induced permeability in unconventional reservoirs[C].ARMA-2015-121,2015:1-15.
[17] WARPINSKI N R,TEUFEL L W.Influence of geologic discontinuities on hydraulic fracture propagation[J].Journal of Petroleum Technology,1987,39(2):209-220.
[18] LASS H,WALKER M.Vector and tensor analysis[J].American Journal of Physics,1950,18(9):583-584.
[19] 吕同富,康兆敏,方秀男.数值计算方法[M].北京:清华大学出版社,2008:1-35.
LYU Tongfu,KANG Zhaomin,FANG Xiunan.Numerical calculation methods[M].Beijing:Tsinghua University Press,2008:1-35.
辽公网安备 21110002000031号 辽ICP备18011648号-1
