低渗透油藏水力压裂井应力场转向定量评价

Quantitative evaluation on stress redistribution for hydraulic fracturing well of low-permeability reservoir

孙峰¹ 李行船² 熊廷松³ 张文豪⁴

中国石油大学（华东）储运与建筑工程学院，山东 青岛 266580 中国石化国际石油勘探开发有限公司，北京 100083 中国石油青海油田公司钻采工艺研究院，甘肃 敦煌 736202 中国石化中原油田分公司采油工程技术研究院，河南 濮阳 457001

基于多孔介质流-固耦合理论和有效应力定律，建立了孔隙压力与地应力相互作用的低渗透油藏水力压裂井应力场转向评价模型，采用有限元数值模拟技术并开发相应程序对耦合模型进行求解，定量分析了低渗透油藏开发过程中水力裂缝附近区域地应力场的变化特征。计算结果表明：水力裂缝导致近裂缝区域地应力场分布特征大幅度改变，沿裂缝与垂直裂缝方向应力场大小变化各向异性，应力场转向范围随初始水力裂缝长度增加而动态变化。

An evaluation model of stress redistribution for hydraulic fracturing well of low-permeability reservoir with the interaction of pore pressure and stress was established on the basis of fluid-solid coupling theory and effective stress principle for porous media. Coupled model was solved through the adaptation of finite element simulation and the development of relevant programme. The change feature of stress field around hydraulic fracture was quantitatively evaluated during the development of low-permeability reservoir. The computed results indicated that hydraulic fracture created the stress redistribution near fracture area was greatly changed, and that the size change of stress field showed the anisotropy along the fracture and vertical fracture direction and the area of stress redistribution was a function of initial hydraulic fracture length.

10.6056/dkyqt201204020