Many multilayer sandstone reservoirs have reached extreme high water content and high recovery stage after long time waterflooding. These inner LPTOLs have been the main potential reserves. Lean-stratified water injection is one of the most important technologies to increase production and develop potential for multilayer oilfields with extreme high water content. However, traditional models cannot entirely solve the inner boundary conditions of lean-stratified water injection. Therefore, we established the injection wellbore constraint equations, which were coupled with the oil/water two-phase numerical reservoir models. Upon an embedded fracture model for simulating hydraulic fractures, a method to simulate the reservoir with horizontal fractures is shown. The influences of reservoir and fluid, horizontal fractures, and injection-production characteristics are analyzed for oil production and water-content dynamic. Considering the specific situation of lean-stratified water injection wells, the influences of different segments numbers, modes of combination in segment layers, and rhythm characteristics of remaining oil reserves and distribution are evaluated.

中文翻译：

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多层储层流动与精细分层注水耦合数值模拟

许多多层砂岩油藏经过长时间的注水，已达到极高含水量和高采收率阶段。这些内部LPTOL 一直是主要的潜在储备。稀薄分层注水是提高含水量极高的多层油田产量和开发潜力的最重要技术之一。然而，传统模型不能完全解决贫分层注水的内边界条件。为此，我们建立了注入井筒约束方程，并与油水两相油藏数值模型相耦合。在用于模拟水力裂缝的嵌入式裂缝模型上，展示了一种模拟具有水平裂缝的储层的方法。储层和流体、水平裂缝、分析了采油和含水动态的注采特征。结合贫化层状注水井的具体情况，评价了不同段数、段层组合方式、剩余油储量与分布节律特征的影响。