USE OF GEOELECTRIC METHODS IN 
SEARCH FOR OIL! 
O. H. GISH? 
Washington, D. C. 
ABSTRACT 
Factors which have adversely influenced opinions and general impressions regard- 
ing the value of geolectric methods as aids in the search for oil are thought by the au- 
thor to be in considerable part of subjective rather than objective origin. However, 
geoelectric methods entered the field relatively late and with inadequate theoretical 
equipment for the best interpretation of results. Furthermore, sources of error which 
doubtless vitiated results have been in some cases overlooked because these did not 
come into serious account in the previous experience of exploration for ores. The prin- 
cipal sources of error for the resistivity method are pointed out. Although electro- 
magnetic and resistivity methods have shown distinct promise in this field, it is, in the 
author’s opinion, not possible-with the data now available to make a reliable compari- 
son, in terms of potential results per dollar, between these and gravimetric or seismic 
methods. 
Published pronouncements on the success of geophysical methods 
as aids to the geologist in the search for oil have been numerous and 
various. It is not intended here to add to the number and it would 
be quite impossible to add to the variety. A careful quantitative 
appraisal of any one method would require the consideration of many 
factors and would accordingly call for a statistical analysis of a great 
mass of data. If all the data now resting in the files of various organ- 
izations were pooled, they would probably be adequate for such a 
study, at least in the case of those methods which have been used 
most extensively. Unless and until such a study can be made, a con- 
siderable diversity of opinion, as to the degree of success of a given 
method under the various conditions thus far encountered, may be 
expected to continue. Such studies of individual methods would con- 
stitute an important preparation for the much more difficult task of 
evaluating the relative merits and determining the particular province 
of each of the different methods. And then there would remain for 
consideration the advantage which accrues from the joint use of two 
or more methods. 
1 Manuscript received, July 21, 1932. 
2 Department of Terrestrial Magnetism, Carnegie Institution of Washington. ihe 
troduced by F. H. Lahee. 
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