单斜稠油油藏蒸汽驱流体界面稳定性分析

ANALYSIS ON FLUID INTERFACE STABILITY OF STEAM FLOODING IN MONOCLINAL HEAVY OIL RESERVOIR

为解决蒸汽驱汽窜机理认识不深入的问题,从蒸汽驱地质物理模式出发,将制约蒸汽驱替稳定性的问题转化为汽液及液液界面稳定性问题。针对宾汉型稠油油藏,以考虑启动压力梯度的广义达西渗流理论为出发点,确定了单斜油层两类界面稳定临界压降和临界流速条件。对影响界面稳定性的诸因素进行敏感性研究。结果表明流度比、重力、热凝析带及聚集带流体启动压力梯度、井距对界面稳定性有显著影响,且对两类界面的影响程度是不同的。为矿场防止及改善汽窜已有的成功实践经验提供了理论依据。

For solving the problem that steam channeling mechanism is not understanded well,starting from geology and physics model of steam flooding,issue of steam flooding stability is converted to one of gas-liquid and liquid-liquid interface stability.Based on general Darcy's law flowing through porous media which includes the threshold pressure gradient effect,stable critical pressure drop and critical flowing velocity two kinds of interfaces are determined in monoclinal heavy oil reservoir.Furthermore,sensitive research on some factors affecting interface stability is carried out.The results show that these factors,namely,mobility ratio,gravity,threshold pressure gradient in heat condensate zone and accumulation zone,producer-injector spacing are significant effect on two kinds of interface stability.Especially,the kind of effect is different to two kinds of interfaces.This research can provide successful empiric on preventing and improving steam channeling with theory base.