【摘要】 在实际油藏开采过程中,储层区域发生地下流体渗流,岩土力学平衡的影响范围大于渗流的计算区域,并影响储层的上覆盖层和下部地层。在流固耦合油藏数值模拟中,地下流体渗流和岩土力学的计算通常采用相同的计算区域,并限定在储层范围内,未考虑完整的应力计算区域,造成计算结果存在偏差。采用改进的有限元—有限体积混合方法,对地下流体的渗流和岩土的力学平衡分别采用不同的计算区域和不同的网格密度进行计算,分析渗流—应力耦合数值计算中计算区域的选取对计算结果的影响。规则储层与背斜圈闭储层算例数值模拟结果表明:应力计算区域的选取影响计算结果,计算结果偏差与非储层区域材料的参数相关,其中拱效应是计算结果出现偏差的主要原因。该结果为流固耦合油藏数值模拟提供指导。更多还原

【Abstract】 For practical procedure of oil production,seepage only happens in the reservoir domain while stress field affects a much larger area which contains the overlying and underlying strata of the reservoir.However,same computational domain restricted in the reservoir stratum is applied for both seepage and stress computation in most of existing seepage-stress coupled modeling researches.In this research,a numerical analysis of the selection of computational domain is carried out.The modified finite element and finite volume method,which applied different computational domains and mesh grids for seepage and geomechanics equations.Results of both regular shape reservoir case and anticline reservoir case show that impact of computational domain on numerical results commonly exists,error size largely depends on the rock properties of non-reservoir strata,arching effect is the main reason for domain-related errors.The obtained results in this paper are of great significance in seepage-stress modeling of petroleum reservoirs.更多还原