应用井壁取心热解分析资料计算剩余油饱和度——以杏树岗油田为例

Estimating remaining oil saturation using sidewall coring analysis data——a case of Xing shugang Oilfield

大庆油田高含水后期剩余油在平面上和空间上分布高度零散,水淹程度评价难度加大,准确求取剩余油饱和度是水淹程度评价的关键。应用数理统计、回归方程原理和岩石热解计算饱和度方法,通过对杏树岗油田2口密闭取心井的岩心与井壁取心分析资料进行对比,介绍了应用密闭取心分析资料对井壁取心分析资料进行2步校正并求取剩余油饱和度的方法,求得了杏树岗油田有效层和表外层的剩余油饱和度计算公式。新建公式计算结果与实际生产数据吻合较好,有效层剩余油饱和度计算公式图版解释符合率达80%以上,表外层剩余油饱和度计算公式图版解释符合率达95%以上。

The distribution of remaining oil is highly dispersed both laterally and vertically at later high water cut stage in Daqing Oilfield. Evaluation of watered out degree is more difficult. It's the key of evaluating watered out degree to accurately calculate remaining oil saturation. Using the principle of data statistics and regressive formula as well as the calculating method by rock pyrolysis, the cores by sealed coring and sidewall coring in two wells are compared in Xingshugang Oilfield. The method of two-step rectifying and calculating remaining oil saturation is introduced by matching the sealed coring analysis data with sidewall coring analysis data. The formula for calculating remaining oil saturations for pay layers and external layers are obtained. The calculating result of the new formula matches well with the production data, the accuracy ratio of the draft is over 80 percent in the effective layers, and is over 95 percent in the external layers.