Abstract: The fluid properties and strata pressure have obviousely changed during the high water cut stage, which exert unfavorable influence on determining formation water resistivity based on spontaneous potential curves. From the analysis of the mechanism for forming SP, formation water resistivity is obtained with spontaneous potential curves. A variety of factors influencing the SP curves in actual production, such as hole diameter, bed thickness, mud invasion, shale content, electrofiltration potential, etc. are analyzed. Correspondent calibrating methods are proposed. Compared with well test data, the result demonstrates that the formation water resistivity can be accurately determined by the method.

Key words: high water cut stage, formation water resistivity, spontaneous potential, electrofiltration potential, correction

摘要： 针对油田高含水期地层流体性质和地层压力的变化给应用自然电位曲线求取地层水电阻率产生不利影响的实际问题，从自然电位产生的机理出发，研究了应用自然电位曲线求取地层水电阻率的方法。对影响自然电位曲线的各种因素(井径、层厚、泥浆侵入、泥质含量、过滤电位等)进行了分析，并对其影响因素提出了校正方法。应用实际测井资料解释，并与试油水分析资料对比，结果表明该方法能够提供可靠的地层水电阻率值。

关键词: 高含水期, 地层水电阻率, 自然电位, 过滤电位, 校正