ly into the reactor jar as the volume decreased. Incubation took place at 28 to 30C 

 until the oxygen was consumed. A daily record of the gas level was kept, indica- 

 ing the rate at which oxygen was consumed by the microorganisms. These values 

 could then be plotted on a graph. The equipment used by Straviniski is shown in 

 Figure 28-6. 



Blau (1943) used a fluorgraphic technique, not as a measure of the fluores- 

 cence of the oil itself, but as a measure of hydrocarbons of high molecular 

 weight that have been formed by the action of certain organisms in the ground 

 such as Bacillus methanicus or Bacillus ethanicus. These bacteria grow pro- 

 fusely in areas of leaking hydrocarbon gases and produce what appeared to 

 Blau to be carboxyllic acids which fluoresce under ultraviolet light. 



Among the variables that affect the bacteria population are, according to 

 Soli (1954), (1) the moisture content of the soil; (2) temperature and pH; 

 and (3) depth and surface-soil type. Beerstecher (1954) gives a more detailed 

 account of the use of bacteria in prospecting for oil. 



Conclusions 



Successful geochemical prospecting for petroleum in this country must await 

 the results of a vigorous integrated program of basic geochemical and geological 

 research. The fruits of such a program would do much to re-establish this field of 

 exploration on a new but much firmer base. The petroleum industry, continually 

 faced with mounting exploration costs is reconsidering geochemical prospecting 

 as an aid to oil and gas discovery. This is evident from a study of the programs 

 of recent scientific society meetings wherein symposia entitled "Geochemistry in 

 Petroleum Exploration" are being held with increasing frequency. 



BIBLIOGRAPHY 



Beerstecher, Ernest, Jr., 1954, Petroleum microbiology: Houston, Elsevier Press Inc., 



p. 204-238. 

 Blau, W., 1943, U. S. Patent 2,337,443: Dec. 21. 



Bokova, E. N., Kuznetsov, V. A., and Kuznetsov, S. I., 1947, Oxidation of gaseous hydro- 

 carbons by bacteria as a basis of microbiological prospecting for petroleum: Akad. Nauk 



SSR Doklady, torn 56, p. 755-757. 

 Campbell, 0. E., 1946, The fluorographic method of petroleum exploration: World Petroleum, 



v. 17, no. 3, p. 54-56. 

 DeMent, J., 1947, Fluorescent techniques in petroleum exploration: Geophysics, v. 12, no. 



1, p. 72-98. 

 Horvitz, L., 1939, On geochemical prospecting: Geophysics, v. 4, no. 3, p. 210-288. 

 , 1949, Geochemical well logging: in a Symposium on Subsurface Logging 



Techniques, Norman, Oklahoma, Univ. Book Exchange. 

 ., 1954, Near-surface hydrocarbons and petroleum accumulation at depth: 



Mining Engineer, v. 6, no. 12, p. 1205-1209. 

 Kalinin, N. A., Savchenko, V. P., and Vasil'ev, V. G., 1955, Summary of conference on 



geochemical methods of prospecting for petroleum and natural gases: Neftyanoe Khoz, 



33, no. 7, p. 55-60. 



632 



