The effect of pressure and temperature on sulphate-reducing bacteria and the action of biocides in oilfield water injection systems

Abstract

The effects of elevated pressures and temperatures on the growth, morphology and metabolic activity of sulphate-reducing bacteria, isolated from the North Sea, are described. Pressure/temperature profiles, growth curves and sulphate reduction rates are presented for several isolates. The maximum pressure and temperature that supported growth were 65 000 KPa and 45°C respectively. The results are discussed in connection with water injection into oil-bearing reservoirs where there is a concern that generation of hydrogen sulphide by sulphate-reducing bacteria may lead to increased hydrogen sulphide levels (souring) in oil and gas, and to corrosion problems in production facilities. The bacteriostatic effects of a number of commercial biocides were enhanced at elevated hydrostatic pressures and temperatures.