CHEMICAL METHODS 



953 



McDermottf reports the presence of waxes and liquids in near-surface 

 soils and finds a close relationship between these materials and petroleum 

 accumulations at depth. In profiles crossing the East Texas Field, he 

 reports the highest concentrations to be associated with the edge of the 

 producing area. 



Ransonel describes the discovery of the Hardy Oil Field, Jones County, 

 Texas, which resulted from a reconnaissance geochemical survey covering 

 most of northeast Jones County. The area surveyed included six producing 

 areas, over all but two of which 

 geochemical anomalies were 

 found. In addition, four anoma- 

 lies were found which, at the time 

 the survey was made, were not 

 associated with known petroleum 

 accumulation. One of these anom- 

 alies now has been proved to be 

 associated with the Hardy Field. 

 It is of interest to note that this 

 field is believed to be of the 

 stratigraphic trap type. 



In carrying out the geochem- 

 ical survey, soil samples were col- 

 lected at depths of 7 feet and 

 analyzed for a constituent, the 

 composition of which is not dis- 

 closed but which is considered to 

 be present in the soil as a result 

 of the upward passage of hydro- 

 carbon gases. 



The geochemical data obtained 

 around the Hardy Field, together 

 with the wells that have been 

 drilled in the area, are shown in 

 Figure 587. 



The fluorographic method, developed by Ferguson and described by 

 Campbell, § involves exposing soil samples to ultra-violet light and recording 

 the emitted light on a light-sensitive medium. The densities of the recorded 

 sample images are measured by a transmission photometer. The fluorescent 

 intensities of the samples are readily derived from the photometer readings, 

 since the densities of the images are directly proportional to the fluorescent 

 intensities of the corresponding samples. 



t Eugene McDermott, "Concentrations of Hydrocarbons in the Earth," Geophysics, Vol. 4, No. 

 3, pp. 195-209, July, 1939. 



t W. R. Ransone, "The Hardy Oil Field, Jones County, Texas," Geophysics, Vol. 12, No. 3, 

 pp. 384-392, July, 1947. 



§ Orton E. Campbell, "The Fluorographic Method of Petroleum Exploration," World Petro- 

 leum, March, 1946. 



Fig. 587. — Geochemical survey of the Hardy 

 Field. Data were originally obtained and map 

 prepared prior to drilling of discovery well. 

 (Ransone, Geophysics, July, 1947.) 



