The field pilot of microbial enhanced oil recovery in a high temperature petroleum reservoir

To evaluate the technical feasibility and effectiveness of improving oil recovery by microbial enhanced water-flooding techniques in high temperature petroleum reservoirs, a field project was initiated with the nature-occurring microorganisms and nutrient injected into an integrated, close Unit with temperature of 73 °C and salinity of 16,790 mg/L in 2001 in Dagang Oilfield, PetroChina. This paper presents the field design and the results of the field pilot with a discussion on characteristics of the reservoir and the performance of the microorganisms injected. Field results show that microorganisms can thrive, proliferate and move in the high temperature reservoir matrix, the positive effect of the bio-treatment first and mainly occurs in those production wells which have good connectivity with injection wells, and the indigenous microorganisms in the petroleum reservoir may also contribute to improving oil recovery due to the injection of nutrient. Results from this project suggest that microbial enhanced water-flooding technique has significant potential for enhancement of oil recovery in high temperature petroleum reservoirs.