特高含水期油藏动用状况评价方法

A油田经过多年注水开发,目前已整体进入高含水、特高含水阶段。针对特高含水期老油田油层动用状况、剩余可采潜力分析和无效水循环等亟待解决的问题,以油田实际数据为基础,作出驱油效率累计分布曲线,对比均质油藏数值模拟结果,并运用数学方法回归拟合曲线,建立了一套油层动用状况的动态评价方法。用该方法评价了B区块油层的动用状况、水驱开发剩余潜力、无效循环厚度和无效循环水量,评价结果较为准确。该方法对特高含水期油田开发调整具有前瞻意义,不仅能方便快速的判断油田目前已动用情况,还能判断油田的剩余开采潜力,更是对特高含水期无效水循环问题定量研究提供了新的解决办法和理论依据。

Evaluating method of the oil reservoir developed condition at ultra-high water-cut stage

After years of water-flooding development, Oilfield A has entered high water-cut and ultra-high water-cut stages in a whole. Aimed at those urgent-to-solve problems including the developed condition, analysis of the remained recoverable potential, ineffective water circulation and so forth at the ultra-high water-cut stage of the old oilfields, based on the actual data of the oilfields, the cumulative distribution curve of the oil displaced efficiency was mapped, the results of the numerical simulation were compared for the homogeneous oil reservoir, and moreover, with the help of the mathematical method, the curves were regressed and matched, a set of the dynamic evaluating method was established for the developed condition. The method was applied to evaluate the developed condition, remained potentiality of the water flooding development, ineffective circulation thickness and water quantity in Block B, the evaluated results were much more accurate. This method possesses the prospective significance for the adjustments of the oilfield development at the ultra-high water-cut stage, it not only can rapidly judge the developed conditions of the oilfield, but also can determine the oilfield remained production potential, and furthermore has provided the new solution and theoretical evidence for the quantitative study on the ineffective water circulation at the ultra-high water-cut stage.