770 



Subsurface Geologic Methods 



plus heavier hydrocarbons is generally indicative of gas-condensate accum- 

 ulations. The pentane plus heavier hydrocarbons predominate over oil 

 reservoirs. 



The hydrogen content reaches a maximum a considerable distance 

 above an accumulation. The amplitude of the hydrogen curve is highest, 

 and the verticle extent of the high values is a minimum near the central 



HIGH CONCENTRATION 

 125 a UP 



INTERMEDIATE CONCENT 

 110- 125 



LOW CONCENTRATION 

 LESS THAN 110 i 



TRACE-ELEMENT SURVEY 

 JONES CO., TEXAS 



RESEARCH INC. 

 lMM I COFFEYVILLE, KAN. 



Figure 410. Concentration distribution of a group of trace ele- 

 ments in top soil from an area in Jones County, Texas. 



part of the accumulation. Near the edge of the accumulation the hydrogen 

 values are lower, but are distributed over a much greater verticle range. 



The logs of nonproductive wells which are only a short distance lat- 

 terly removed from known fields show extremely low hydocarbon concen- 

 trations throughout the section. 



Analyses for the inorganic constituents of well cuttings have been 

 found to be most useful as an aid in lithologic correlation. Small amounts 

 of chlorides and sulfates often influence the electrical-log interpretation 

 more than their percentage composition would suggest. 



