大45超低渗透油藏非线性渗流数值模拟

为了评价非线性渗流规律下的井网适应性,以大45超低渗透区块为例,应用研制的非线性渗流数值模拟软件进行数值模拟研究.设计6套井网转注方案研究不同转注时机对油田开发的影响,并优选最优方案.研究表明:非线性渗流数值模拟软件适用于超低渗透油藏;大45油藏现有菱形反九点500 m×100 m井网动用程度低,井网适应性差,需通过井网调整改善油藏动用程度;越早转注,采出程度越高;综合含水率60%左右为最佳转注时机;井网转注提高了地层压力梯度,增大了流动区域,进而改善了油田的开发效果;超低渗透油藏开发过程中,非线性渗流占据了流体渗流的主导地位,以非线性渗流规律为基础的数值模拟软件能够更准确地预测该类型油藏的开发特征.

Numerical simulation of nonlinear seepage in Da 45 super-low permeability reservoir

The nonlinear seepage in Da45 super-low permeability reservoir is simulated using newly developed software for evaluating the well pattern adaptability of nonlinear seepage reservoirs.Six well pattern water injection timing projects were designed for identify the effect of different water injection conversion timings on reservoir development result.And the optimum well pattern water injection timing was obtained.The study shows that,the nonlinear seepage numerical simulation software is suitable to super-permeability reservoirs;present 500 m×100 m rhombic inverted nine-spot well pattern of Da45 super-low permeability reservoir has low producing degree,so it is needed to improve the reservoir producing degree by water injection;the earlier water injection conversion,the higher recovery factor;the optimum water injection conversion timing is at 60% water cut;well pattern water injection can increase the reservoir pressure gradient and seepage region,and therefore improve the reservoir development result;nonlinear seepage plays a dominant role in the exploitation of super-low permeability reservoir,so the reservoir numerical simulation software based on nonlinear seepage law can accurately predict the development characteristics of super-low permeability reservoirs.