This paper presents a coupled finite element approach for modeling geomechanical effects induced by production/injection processes in petroleum reservoirs. The module developed employs coupled- reservoir analysis using CMG IMEX® as the flow simulator and a finite element program in MATLAB® as the stress–strain simulator, in a two-way explicit partial coupling scheme. The flow and mechanical problems are coupled by the change of effective stress due to the change in pore pressure and by varying stress-dependent reservoir properties, such as pore compressibility, absolute permeability, and porosity. The coupling procedure was applied to the Namorado Field (Campos Basin, Brazil) to quantify the impact of the rock deformation on fluid recovery. Based on the cases studied, the coupled analyses predicted higher oil recovery than the conventional reservoir simulations. The results showed that the reservoir deformation can affect its performance and must be taken into account in reservoir-engineering studies depending on production strategy and reservoir stiffness. Besides, the geomechanical calculations were performed only in the coupling timesteps, reducing the computational effort and making this coupling method feasible on a field scale.

本文提出了一种耦合有限元方法，用于模拟石油储层中生产/注入过程引起的地质力学效应。开发的模块采用耦合储层分析，使用 CMG IMEX® 作为流动模拟器，在 MATLAB® 中使用有限元程序作为应力-应变模拟器，采用双向显式部分耦合方案。流动和力学问题是由孔隙压力变化引起的有效应力变化以及与应力相关的储层性质（如孔隙压缩率、绝对渗透率和孔隙度）的变化相互耦合的。耦合程序应用于 Namorado 油田（巴西坎波斯盆地），以量化岩石变形对流体采收的影响。根据所研究的案例，耦合分析预测的石油采收率高于传统油藏模拟。结果表明，油藏变形会影响其性能，在油藏工程研究中必须根据生产策略和油藏刚度加以考虑。此外，地质力学计算仅在耦合时间步长中进行，减少了计算量并使这种耦合方法在现场规模上可行。