柳东地区岩石电阻率实验及数值模拟研究

在石油勘探与开发过程中，油气层的划分主要依靠电测井资料。然而在注水开发油区或地层水多变油区，地层电阻率的大小不仅受到地层含油性的影响，同时也受到地层混合液电阻率的影响，从而给油气层识别造成困难。依据实验室模拟油田水淹过程的岩电关系，结合计算机数值模拟，得出淡水水淹的减饱和油过程的岩心电性变化规律。研究结果表明，水淹过程中岩石电阻率与含水饱和度之间的关系曲线基本为“Ｓ”型，目前国内外常见的“Ｕ”型曲线仅是“Ｓ”型曲线的一种特例。分析了曲线形态的影响因素，为正确评价地层的含油性提供了较可靠的理论依据。

EXPERIMENTAL STUDY ON ROCK RESISTIVITY OF LIUDONG OILFIELD AND DIGITAL ANALOGY

In oil exploration and development, hydrocarbon zone marking mainly depends on resistivity logs. Formation water in waterflood area is changeable. So not only hydrocarbon saturation but also formation water resistivity affects formation resistivity. On the basis of displacement measurements of waterflood simulation in laboratory and digital analogy, this paper provides the pattern of electric properties of core in the process of decreasing oil saturation of fresh water injection. It shows that the relation curves between waterflooded rock resistivity and water saturation are sigmoid, and U type curve is only a special case of sigmoidal curves. Some factors influencing curve type are analyzed, which provides a reliable theory for formation evaluation.