低渗砂岩力学试验及复杂断块裂缝分布预测研究  

Sandstone mechanics parameter test and research on fracture distribution in complex fault block

作　　者：赵新波 熊光勤[2] 刘桂玲[2] 田炜 闫相祯 

机构地区：[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

出　　处：《中国测试》2015年第3期1-7,共7页China Measurement & Test

基　　金：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)

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。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.

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 

分 类 号：TE31[石油与天然气工程—油气田开发工程] P631.81[天文地球—地质矿产勘探]