考虑压力约束的精细分层注水耦合调配模型

A Coupling Allocation Model of Finely Layered Water Injection Considering Pressure Constraint

为解决现有常见分层注水调配计算模型考虑因素不全、模型计算精度较低的问题,建立了井筒管流–水嘴孔流–地层渗流的耦合模型,计算分层注水量,并考虑井口压力及地层压力的约束条件,构建了一种分层配水器水嘴调配反演计算方法,分析讨论了不同条件下模型正演及反演计算结果。分析结果表明,所建模型能够精确计算不同时刻各注水层的注入量及压力,单层配水器水嘴直径与该层注入量呈正相关关系,与其他层注入量呈反相关关系。该模型能够在满足压力约束条件的情况下给出最优水嘴调配方案,为分层注水提供一种较精确的注水量计算及配水器水嘴调配方法,指导现场分层注水调配工作。

In order to solve the problems of non-comprehensive consideration of factors and low calculation accuracy of existing calculation models for layered water injection allocation,a coupling model featuring wellbore pipe flow,nozzle orifice flow,and formation seepage was established,to calculate the layered water injection volume.Meanwhile,an inversion calculation method for the nozzle allocation of layered water distributors was established by considering the constraints of wellhead pressure and formation pressure.In addition,the forward and inverse calculation results of the model under different conditions were discussed.The results indicated that the established model could accurately calculate the injection volume and pressure of each water injection layer at different times.The diameter of the single-layer water distributor’s nozzle was positively correlated with the injection volume of the layer and inversely correlated with the injection volume of other layers.The established model could give an optimal nozzle allocation scheme while meeting the pressure constraint conditions,provide a more accurate injection volume calculation and nozzle allocation method of water distributors for layered water injection technology,and guide on-site layered water injection allocation.