作者：赵新波1, 熊光勤2, 刘桂玲2, 田炜3, 闫相祯1
作者单位：1. 中国石油大学(华东)油气CAE技术研究中心, 山东 青岛 266580;
2. 中国石化江苏油田分公司地质科学研究院, 江苏 扬州 225009;
3. 中国石油华北油田公司, 河北 任丘 062550
关键词：巴西试验;裂缝分布;非连续模型;地应力场;优化反分析
摘要：
通过岩石抗拉强度试验和快速直接剪断试验对江苏油田某区块多口油井岩芯进行试验,获取相应层段的岩石抗拉强度及抗剪强度,利用测井资料中的声波等数据得到井筒附近的岩石力学参数.应用非连续模型中的接触单元描述断层系统与地层间的非连续错动,考虑沉积相引起地层的非均质性,运用多目标约束优化反分析法对江苏油田某区块含复杂断裂系统的致密砂岩油藏地应力场进行有限元数值模拟,实现地应力场的精细预测,得到复杂断块致密砂岩油藏地应力场等值线图.针对区块出现拉伸破坏和剪切破坏,利用Griffith张破裂准则和Coulomb-Navier剪破裂准则对油藏区域进行拉伸裂缝及剪切裂缝预测,最终得到裂缝综合发育分布图,确定裂缝相对发育区域.研究结果表明:断层歼灭处及复合断层交叉处地应力变化较大,对地应力场分布影响较大;断层内部裂缝较为发育,受断层系统影响复杂的区域,裂缝发育不均衡,且裂缝发育程度受沉积相的影响较大.
Sandstone mechanics parameter test and research on fracture distribution in complex fault block
ZHAO Xinbo1, XIONG Guangqin2, LIU Guiling2, TIAN Wei3, YAN Xiangzhen1
1. Oil and Gas CAE Technology Research Center in China University of Petroleum, Qingdao 266580, China;
2. Geological Scientific Research Institute of Jiangsu Oilfield Company, SINOPEC, Yangzhou 225009, China;
3. Petrochina Huabei Oilfield Company, Renqiu 062550, China
Abstract: Based on rock tensile strength test and fast direct shear test, drill cores of many oil wells in Jiangsu oilfield were tested, rock tensile strength and shear strength in this block were obtained. Using logging information containing acoustic data, wellbore rock mechanics parameters can be gained. The discontinuous dislocation between fault system and formation were described by applying contact unit of the discontinuous model. By considering heterogeneity of the formation caused by sedimentary facies, and doing FEM numerical simulation for the in-situ stress field of tight sandstone reservoirs in a block of Jiangsu Oilfield containing complex fracture system by using the multi-objective constrained optimization anti-analysis method, the fine forecast of stress field for small-block oilfield was achieved. The in-situ stress field contour map in was got by tight sandstone reservoir containing complex fault block. Rock tensile failure and shear failure regularly occurred in this block, so Griffith strength theory and Coulomb-Navier strength theory were used to predict tensile faults and shear faults, respectively. The difference of sedimentary facies could lead to larger gradient of stress field in the edge of ground. Among the influence of fault system impact on the ground stress, the main control factors were the elastic modulus of fault and the fault strike. The crustal stress, which came from the ends of faults and the vicinity of the cross of complex faults, had a larger change and a larger effect on ground stress field distribution. Fractures were more developed internal faults and fracture development was imbalanced in field that contained many faults and much influenced by sedimentary facies.
Keywords: brazil test;fracture distribution;discontinuous model;crustal stress;inverse reliability-based approach
2015, 41(3): 1-7 收稿日期: 2014-10-12;收到修改稿日期: 2014-11-17
基金项目: 国家自然科学基金项目(51274231、51374228、U1262208);国家科技重大专项资助(2011ZX05037-04);中国石油天然气集团公司资助项目(2014A-4214)
作者简介: 赵新波(1986-),男,山东邹城市人,博士研究生,主要从事油气田地下工程力学方面研究.
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