介质变形对低渗透油藏压裂产能影响有限元模拟

针对介质变形对低渗透油藏压裂产能影响的定量评价问题，建立了介质变形 渗流耦合模型，并应用有限元数值模拟技术对耦合模型进行求解；采用裂缝单元模型处理水力裂缝与储层区域离散的网格尺度协调问题，即将裂缝单元的质量、刚度矩阵变换叠加到储层整体模型矩阵中模拟压裂后的开发动态。模拟分析结果表明，介质变形造成储层渗透率变化是低渗透油藏压裂产能下降的重要因素，随裂缝长度增加和生产压差增大，其影响效应更加显著。

Finite element simulation on effects of medium deformation on hydraulic fracturing deliverability of low-permeability reservoir

In order to evaluate the sensitivity of medium deformation to the fracturing deliverability of low-permeability reservoir, the medium deformation and fluid seepage coupling model was established. The finite element method was used to solve the coupled governing equation. The fracture element was used to treat the mesh dimension problem between reservoir and fracture. The mass and stiffness matrixes of fracture element were transformed to the whole system of coordinates, assembling the matrixes and solving the finite element equations. The numerical simulation results indicated that the permeability loss resulted from the medium deformation is a key factor for decreasing hydraulic fracturing deliverability. The influence of the medium deformation gets more seriously while increasing the pressure drawdown and fracture length.