淡化系数方程在稠油水淹层测井评价中的应用

Application of Freshening Factor Equation to Calculating Residual Oil Saturation in Steam Soak Reservoir

孙德明等：淡化系数方程在稠油水淹层测井评价中的应用，测井技术，１９９６（５）２０，３４１～３４４。稠油水淹层为蒸汽吞吐开采，地层压力下降，地层水因蒸汽注入而淡化。由于稠油在井下保持凝固状态，用常规产水率来判别水淹层的方法在稠油层无法使用。本文用淡化系数方程求剩余油饱和度，用建立的过滤电位方程对ＳＰ曲线进行校正，然后利用校正的数据计算地层混合液电阻率。该模型共处理几十口井，水淹层解释符合率达８４．６％，填补了稠油层的水淹测井解释在国内的空白。

Steam soak is adopted for heavy oil water flooded reservoir in Liaohe Oil Field. There are two characteristics which affect log interpretation for steam soak reservoir:(1) Formation pressure declines greatly, which makes the effect of streaming potential on SP serious, and the salinity of connate water is freshened gradually; (2) The traditional equation for R w is not suitable for heavy oil reservoir, because the heavy oil is not movable under reservoir conditions without injection of steam. Therefore, it is hard to make log interpretation for steam soak reservoirs. Considering the above mentioned problems, a new equation for streaming potential is established to eliminate its effect on SP. Then the corrected SP is used to determine the formation water resistivity in steam soak formation. After the R w is calculated, the equation of freshening factor is used to determine the residual oil saturation. Logging data from more than 20 wells are processed with the above technique and 84 6% of the interpreted results coincides with the test results.