激发极化法探测油气田——异常成因及其与油气藏关系的探讨

根据1982年以来在华北、西南、西北、华东等地大小20余个油田上进行激电找油的研究工作,特别对西北K区等油田进行的异常成因机制的剖析工作:激电测井、井中取样分析鉴定、扫描电镜观察、物性测定、数字模拟及同位素分析等,以充分论据证实了引起激电异常的主要地质因素是油藏上方浅部地层中的次生黄铁矿化分布。论述了黄铁矿化与烃类扩迁的密切关系。并对西北K区等油藏上方地层的垂向物质变异的规律,结合实际资料,从理论上进行了分析和解释。最后提出了油藏上覆地层垂向变化的地质-地球化学-地球物理综合参考模型。

INDUCED POLARIZATION （IP） METHOD IN OIL EXPLORATION——THE CAUSE OF IP ANOMALY AND IT'S RELATION TO THE OIL RESERVOIR

Since 1982, we have taken IP research for oil exploration at more than 20 oil fields in different parts of China. This paper takes the oil field in region K at north-west of China, as a main example, to examine the mechanism of the cause of the IP anomaly over oil reservoir in detail. According to the results of many different kinds of physical and chemical determinations and analysis, we have come to the conclusion that the main geological factor which causes the IP anomaly is the pyrite mineralization distributed in the shallow layers over the oil reservoir. We infer that the pyrite mineralization relates closely to the diffusion or escape of the hydrocarbon substance from the oil reservoir. Along the vertical direction, the variation of the substance in the overburden layers has been investigated theoretically and practically. Thereby, we provide a referable geologecal-geochemical-geophysical model which refers the vertical variation of the material and of the ρs, Ms property of the overburden layers.