OUR PETROLEUM SUPPLY — MISER 309 



The practice of obtaining cores of oil sands and other important beds 

 in order that their character may be accurately noted is used in all 

 producing areas. The microscopic study of insoluble residues ob- 

 tained by dissolving in hydrochloric acid well cuttings of limestones 

 and dolomites was begun in 1924 by H. S. McQueen (10) . It has been 

 successfully utilized by the oil industry in the midcontinent region — 

 from Ohio and Tennessee on the east to Kansas and New Mexico on 

 the west — for the determination of underground stratigraphy and 

 structure. 



Micropaleontology, first introduced in universities and also by 

 companies to a limited extent as early as 1919, became an integral 

 part of the oil business in the United States in 1924. 



Geophysical methods, magnetic, gravimetric, electrical, and seis- 

 mic, are widely used in the United States by the oil industry as a 

 means of locating and mapping buried structural features. The 

 adoption of the seismograph followed the discovery of its applica- 

 bility during the World War for locating long-range guns. In its 

 use by the oil industry the long-range guns are replaced by explosive 

 charges in prospective oil localities. The first applications of gi*avi- 

 metric methods in the detection of anticlinal structure in this country 

 were made in 1917 and 1919 by the Coast and Geodetic Survey when 

 stations on Damon Mound, Tex., and Paleozoic folds in Maryland 

 were occupied at the request of David White of the Geological Survey 

 (22). In 1924 oil companies located three salt domes by geophysical 

 methods, the Nash dome by means of the torsion balance, the Orchard 

 dome by the seismograph, and the Long Point dome by both the 

 torsion balance and the seismograph. Since 1924 a total of about 

 100 salt domes in the Gulf Costal Plain and many other structural 

 features from New York to California have been found by means of 

 geophysical methods. 



A type of well record or log, known as an electrical log, was devel- 

 oped in 1928. This type of well record is a great aid in exploratory 

 drilling and the exploitation of oil fields. It shows the electrical 

 resistivity and the relative porosity of the beds passed through by the 

 drill. It permits the identification of oil- and water-bearing sands 

 and gives useful information concerning the character of the beds. 

 This information, in many areas, is more accurate than that provided 

 by sets of cuttings. 



PROGRESS OF PETROLEUM GEOLOGY 



The progress of the science of petroleum geology is revealed in 

 many publications, particularly those of the Federal and State Geo- 

 logical Surveys and the American Association of Petroleum Geolo- 

 gists. This Association was organized in Tulsa, Okla., in 1917 with a 

 membership of 94 and now (December 1938) has a domestic and 



