油井中混合流体电导率与持水率关系研究

对于油井中的混合流体来说，在一定的温度、压力条件下，混合流体的流动状态与导电特性主要取决于油、气、水的相对比例和分布状况。目前中国油田大多数处于高含水阶段，生产测井井段的流动几乎90％都是泡状流动，其形状可分为圆球状和椭球状。发现多数情况下油、气是呈圆球状泡体向上运动的，仅在趋近于过渡带时才出现椭球状泡体。为此推导了油、气泡分别呈圊球状和椭球状泡状流动时油、气电导率与持水率的关系式，发现混合流体电导率值相差很小。认为不同持水率的电导率变化范围很大．而且生产井中的水包括原生地层水和注入水，其结果必然造成生产井中地层水的电导率大幅度变化。

Correlation between Conductivity and Water Holdup of Mixed Fluids in Oil Wells

For mixed fluids in oil wells, under the conditions of certain temperature and pressure, its conductive characteristics depends mainly on the relative proportion and distribution of oil, gas and water. While for the relative proportion of oil, gas and water in the wellbore, the distributional status of water holdup is different, for the flowing status of mixed fluid, the flow pattern is different. At present, the most of the Chinese Oilfields are at the stage of high water cut, the flow patterns in production logging sections are mostly 90% of froth flow. In the mixed fluids the shapes of oil-gas bubbles can be divided into a ball shape and an ellipsoidal shape. It is found out that at the most of times oil and gas move upward in the shape of ball bubble, and appear in ellipsoidal shape only in the situation approaching to intermediate belt, which is rarely seen in the oilfields. The relationships between conductivity and water holdup of oil and water bubbles are analyzed respectively under the conditions of ball and ellipsoidal shapes when the mixed fluid is in froth flow. It is considered that the conductivities of different water holdup varies greatly, and water in production wells includes primary formation water and injection water, by which great variation of formation water would be caused for formation water conductivity in production wells.