电场差分法理论研究

对均匀大地和二层大地的频率域电场差分法理论曲线进行的计算和研究表明,电场差分法是一种以目标地质体和围岩在电阻率和极化率方面的差异为基础,根据测量到的能明显反映激电响应与电磁耦合响应的比值随频率变化的P参数曲线在性态上的差异来圈划油气藏的一种电法勘探方法. 因为它圈划油气藏的物理基础是油气藏上方与围岩上方测量到的电磁耦合响应和激电响应的差异,所以在圈划油气藏方面,该方法与复电阻率法类似,同样具有找油气的优良性能. 此外,该方法与复电阻率法相比,具有对目标地质体和围岩的电阻率和极化率差异反映灵敏、效率高、成本低等优点,所以它是一种值得推广的找油气的电法勘探方法.

A THEORETICAL STUDY ON DIFFERENTIALLY-NORMALIZED ELECTRICAL PROSPECTING METHOD

The theoretical curves of frequency domain Differentially normalized Electrical prospecting Method for a homogneous earth and a 2 layer earth show that the method is based on the difference in resistivity and chargeability between a geological target and its country rock. This method is used to delineaste oil and gas deposits according to the behavior of measured P parameter curves which shows the variation of the ratio of IP response to EM coupling response with frequency. Since the physical basis to delineate an oil and gas deposit is the difference between EM coupling responses and IP responses measured over an oil and gas deposit and its country rock,in the field of delineation of oil and gas deposits,the method is similar to CR method and possesses the good quality of delineation of oil and gas deposits which CR method has. In addition,compared with CR method,the method has many advantages,such as sensitivity to the difference in resistivity or chargeability between a geological target and its country rock,higher efficiency and lower product cost etc. Therefore,it is a recommendable electrical prospecting method in oil and gas exploration.