辽河油田曙一区杜84块兴隆台油层构造应力场研究

摘要

By analyzing the strata and geological structures of Liaohe oil field,this paper studied the structural pattern and the features of main faults in Block 84.Then,a three-dimensional geological model was built and finite element simulation of tectonic stress field was carried out.It is shown that the stress regime in Block 84 is characterized by the maximum and intermediate principal stresses being horizontal and the minimum principal stress being vertical.Under the action of this stress regime,faults in the region have the trends of normal dip-slide with lateral movement.Three-dimensional finite element simulation indicates that (1) compressional and shear stresses are concentrated along faults,which favors the extensional movement with lateral sliding of faults,(2) there are stepped normal fault displacement and (3) fissures may be produced locally in the rock masses.%根据辽河油田已有地层、构造资料，研究了杜84块构造格架、主要断裂特点，在此基础上,建立了构造应力场模拟的三维地质模型，用3D-σ软件进行了构造应力场三维有限元模拟研究。其结果表明，杜84块油层受构造应力状态为最大和中间主应力近水平，最小主应力垂直。在此应力场作用下，区内断层运动方式为正断兼水平扭动。三维有限元模拟计算结果表明，沿断层带均发生压应力和剪应力集中现象,从而有利于断层发生扭张性运动。位移分析表明，有明显的呈阶梯状组合的正断位移。据破坏率分析，在现有应力场作用下，油层所在岩体局部会产生裂缝。