Electrical-prospecting methods may be used in an exploration program in one of three ways. (1) They may be used to determine the depth to resistant basement rock. (2) They may be used to detect directly the presence of oil. (3) They may be used to map variations in texture associated with lithologic traps.

Electrical-prospecting methods are being used extensively in some parts of the world for mapping major structural features within sedimentary basins, but in the United States seismic methods have proved to be far more effective for such studies. Electrical-prospecting methods have been used in the past to detect increases in resistivity caused by the presence of oil, but such applications have been limited to very shallow occurrences. The direct discovery of oil by electrical methods at greater depths would require great improvement in techniques. Electrical methods have been little used in the study of lithologic changes in a sedimentary column associated with oil traps. The Department of Geophysics at the Colorado School of Mines has been investigating such an application, using bot well logs and field surveys from the Denver basin.

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