特高含水期多层合采油藏油井液量调配优化方法

Optimization Method of Oil Well Fluid Allocation in Multi-layer Commingled Production Reservoir at Ultra-high Water Cut Stag

水驱油藏进入特高含水期,井网相对固定,受储层非均质性的影响,油井含水差异大,油井液量调配是改善油井开发效果差异的经济有效的主要措施。为建立油井液量调配的优化方法,以多层合采油藏中一注多采井组为例,考虑特高含水期储层物性参数和剩余油分布的非均质特征,将一注多采井组等效为多个一注一采井组;综合考虑渗透率和原油黏度的时变特征以及注水启动压力,建立了一注一采多层合采剖面模型开发指标的计算方法,以油井液量调配后各油井含水率趋于一致为目标,采用迭代法计算得到油井调配所需液量。经过数值模拟验证表明,采用建立的油井液量调配优化方法得到的液量进行生产,在给定的调配时间内油井能够达到相近的含水率,有效改善了水驱开发效果。

With the water drive reservoir entering the ultra-high water cut stage, the well pattern is relatively fixed. Affected by reservoir heterogeneity, water cut in oil wells varies greatly. Oil well fluid allocation is a main economic and effective measure to improve the development difference of oil well. In order to establish the optimized method of oil well fluid allocation, considering the heterogeneous characteristics of reservoir physical parameters and remaining oil distribution in the ultra-high water-cut period, one injection multi production well group in multi-layer combined production reservoir was taken as an example and one injection multiple production well group was considered equivalent to multiple one injection one production well group. Considering the time-varying characteristics of permeability and crude oil viscosity as well as the starting pressure of water injection, a profile model of one injection and one production was established to calculate the development index. By equating one injection and multiple production well group to multiple one injection and one production well groups, aiming at reaching the same water cut after the allocation of oil well fluid volume, the required fluid volume for oil well allocation was obtained by iterative method. The results of numerical simulation show that the water cut of the oil wells within a given time is similar, and the effect of water flooding development is effectively improved.