METABOLISM OF LOWER ALCOHOLS, ACETATE, AND BICARBONATE IN WATER-FLOODED OIL STRATA

Anaerobic methanogenic, acetogenic, sulfate-reducing bacteria were sho wn to be present in stratal waters of oil fields in Tataria having var ious salinity levels. The substrates used to reveal these bacteria wer e H-2 /CO2, methanol, or acetate for methanogens, H-2/CO2 and methanol for acetogens, and lactate and acetate for sulfate reducers. The anal ysis of C-14-bicarbonate, acetate, and methanol incorporation into bac terial biomass turned out to yield more information than the microbiol ogical analysis. As a rule, the highest incorporation rate was recorde d for bicarbonate (up to 17.2 mu g C.liter(-1).day(-1)); a lower rate was recorded for acetate (up to 12.6 mu g C.liter(-1) day(-1)) and for methanol (up to 6.2 mu g C.liter(-1).day(-1)). In the injection well near-bottom zone, acetate was incorporated at a higher rate than bicar bonate. The higher rate of acetate incorporation correlates with the p resence of sulfate- and Fe-reducing bacteria oxidizing acetate. The re asons for the increased rate of C-14-methanol incorporation into bioma ss in some samples of saline water are discussed. The rate of acetate oxidation was tenfold to a hundredfold higher than that of its incorpo ration into biomass.