Geomicrobiological oil prospection

Abstract

The sensitivity of hydrocarbon bacteria toward concentrations of gaseous hydrocarbons in soil atmosphere above two oil deposits was studied. Bacteria capable of oxidizing methane, ethane and propane were used. The investigation produced the following results: (1) Methane-oxidizing bacteria were found to grow in all bores tested and the degree of their multiplication differed very little (1–3 x 107). The value of multiplication of methane-oxidizing bacteria could not be used for cartographic treatment of the results. Methane was utilized at concentrations as low as 10-5 % (v/v). (2) Propane-oxidizing bacteria utilized higher gaseous hydrocarbons at a concentration of 10-5% (v/v). The differences in the intensity of their multiplication make it possible to differentiate between concentrations of higher gaseous hydrocarbons in the soil atmosphere within the range of 10-5 to-4% (v/v). (3) The results of the investigation of ethane and propane-oxidizing bacteria made it possible to map the areas with different concentrations of higher gaseous hydrocarbons. (4) Sufficient sensitivity of hydrocarbon bacteria for distinguishing between concentrations of gaseous hydrocarbons above oil deposits and outside of them was established. An informative comparison of the position of bacterial anomalies and of the position of deposits revealed essential agreement in the localization of bacterial minima above the productive area of the deposit.