井-地电位成像技术及其在孤东八区剩余油分布研究中的应用

利用传输线理论讨论了套管供大电流时井眼、套管内和套管外水泥环及地层中的电流分布。介绍了井地电位测量技术的方法及原理 ,重点分析了井地电位测量数据的成像方法。利用井地电位测量技术取得了孤东油田八区 2 6 J9井区的野外实测电位数据。用数值模拟和反演成像方法对实测电位数据进行了处理 ,得到了 2 6 J9井区目的层的电阻率和剩余油饱和度分布。对本区构造、岩性及反演得到的电阻率数据分析可知 ,近南北方向有一条渗透性较好的优势通道 ,注水水洗及聚合物驱较为充分 ,剩余油饱和度相对较低 ;在高渗透带的两侧非均质性严重 ,水洗不充分 ,这是今后注聚合物封堵和调整挖潜应考虑的因素。与测试、生产动态和其他开发地质资料对比表明 ,井地电位测量资料的结果与其他监测资料吻合较好 ,剩余油平面分布和层间分布与智能测试结果一致 ,显示了井地电位测量技术的良好应用前景

Borehole-to-surface electrical imaging technique and its application to residual oil distribution analysis of the eighth section in Gudong Oilfield

The transmission-line theory was used to analyze the electric current distributions in domains of the in-borehole, casing pipe and out-of-casing cement sheath, when the casing pipe was energized by large current supply. The methodology of the borehole-to-surface electrical measurement was described. The borehole-to-surface electrical measurement imaging technique and its initial application in the eighth section of the Gudong Oilfield were discussed in detail. The data in the area of the borehole of 8-26-J9 were obtained with the borehole-to-surface electrical measurement method. The data set was numerically simulated and inverted to produce the resistivity and the residual oil saturation distributions of the target zones. The structure, lithology and resistivity of this area derived from the borehole-to-surface electrical measurement were compared with the results of the dynamic production tests and other geological data. Those results showed a sound consistency. Moreover, the residual oil saturation distributions between intervals and in lateral are in good agreement with that of the intelligent production tests.