摘要
为了认识低渗透油藏的水驱动态规律,完善低速非达西渗流的水驱动态理论,该文基于流管法的基本原理,给出了五点法井网的三角流管模型,引入启动压力梯度,建立了低渗透油藏水驱动态开发指标的油藏工程计算方法。经对比验证,利用该方法计算的产油量与实际产量一致,若不考虑启动压力梯度会导致产油量偏高,存在较大误差。绘制并分析了渗流阻力、含水饱和度、产油量、产水量、采出程度以及波及系数等动态指标的变化曲线。结果表明,随着注入水从主流管向外的扩展,水驱前缘推进变慢,渗流阻力也随之变大,流管中注入水突破变慢。主流管突破后产油量迅速下降,开始迅速产水,采出程度和波及系数增幅变缓。所有流管都突破后产量和采出程度趋于平缓,注入水完全波及。同一时刻水驱前缘后从注入井端到采油井端的含水饱和度不断减小。研究结果可为低渗透油田水驱开发及动态分析提供指导。
In order to get an understanding of change rules of water drive performance in low permeability reservoirs, and to improve the theory of water drive performance of non-Darcy flow with low velocity, the triangle streamtube model of five-spot pattern was established based on the basic principle of streamtube method. With the introduction of threshold pressure gradient, a method of the reservoir engineering calculating indexes of water drive performance was established in low permeability reservoirs. Through verification by comparison, the oil production rate calculated by this method was consistent to the actual data, and its result got bigger without consideration of threshold pressure gradient, having a big error. Changing curves of dynamic indexes of resistance to flow, water saturation, oil production rate, water production rate, recovery percent of reserves and sweep efficiency were drawn and analyzed. The results show that along with the expansion of injection water from the main streamtube to the outside, the slower waterflood front advances, resistance to flow becomes bigger, so the later water break throughs in the streamtube. After the main streamtube breakthrough, oil production rate rapidly decline, water production rate rapidly rises, recovery percent of reserves and sweep efficiency increase slowly. After all the streamtube breakthrough, production rate and recovery percent of reserves levels off, the injected water completely spreads. At the same time, water saturation falls from the injection well to production after waterflood front. The results offer an effective guidance for water flooding development and dynamic management of low permeability oilfield.
出处
《水动力学研究与进展（A辑）》
CSCD
北大核心
2017年第6期704-711,共8页
Chinese Journal of Hydrodynamics
基金
黑龙江省自然科学基金资助项目(E2016015)~~
关键词
低渗透油藏
流管法
启动压力梯度
水驱动态
low permeability reservoir
streamtube method
threshold pressure gradient
water drive performance
