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最近几年,人们提出了利用电法来寻找油气藏的可能性。如果从不同地电断面所表征的若干油田电测井资料的研究中,可以确定平均地电参数的话中,那么,利用各种电测深资料来定量解释异常是可以实现的。由深部含油层所引起的直流视电阻率异常,取决于含油层上下岩层的电阻率,以及所采用的电极装置形式。径向偶极装置将得到最大的异常值,其次才是其他电极装置,象施芦姆贝格尔装置和温纳装置。当目的层下部的电阻率比上部低的时候,就会获得最大视电阻率异常;视电阻率的相对异常总是和含油层与上覆岩层横向电阻的比值相同。当采用径向偶极装置的时候,有限延伸的含油层并不使无限延伸含油层异常值发生明显的改变,在此情况下最小极距大约为埋藏深度的4倍。在含油层附近,埋设一个供电电极就会使异常幅值增大;最大异常出现在和深度相接近的极距上。在若干油田中,只有0.1～10％的油田能够引起典型的视电阻率异常。对于较大的油田可以探测到这些异常,而对较小的油田则必须在改善电测深方法的探测能力之后,才能探测到它的异常。
In recent years, people have proposed the possibility of using electricity to find reservoirs. If it is possible to determine the average geoelectric parameters from the electrical logging data of several oil fields characterized by different geoelectric sections, then it is feasible to use a variety of electrical sounding data to quantitatively explain the anomaly. The DC apparent resistivity anomalies caused by deep reservoirs depend on the resistivity of the upper and lower strata of the oil-bearing formation and the form of electrode assembly used. Radial dipole devices will get the most outliers, followed by other electrode devices, like Schlumberger devices and Winner devices. When the resistivity of the lower part of the target layer is lower than that of the upper part, the maximum apparent resistivity anomaly is obtained. The relative abnormality of apparent resistivity is always the same as the ratio of the lateral resistance of the oil-bearing layer and the overburden. When using a radial dipole device, the limited extension of the oil-bearing layer does not significantly change the outlier of the infinitely extended oil-bearing formation, in which case the minimum pole-pitch is approximately 4 times the buried depth. In the vicinity of the oil-bearing layer, laying a power supply electrode will make the anomaly amplitude increase; the maximum anomaly appears in the polar distance close to the depth. In some fields, only 0.1 to 10% of the fields can cause typical apparent resistivity anomalies. These anomalies can be detected in larger fields, whereas in smaller fields, the anomalies must be detected before the sounding capabilities of the electrical sounding method are improved.