Microbe-Enhanced Oil Recovery Technology Obtains Huge Success in Low-Permeability Reservoirs in Daqing Oilfield

Guo, Wankui (Daqing Oilfield Co. Ltd) | Shi, Chengfang (Daqing Oilfield Co. Ltd.) | Yang, Zhenyu (Daqing Oilfield Co. Ltd.) | Hou, Zhaowei (Daqing Oilfield Co. Ltd.) | Jin, Rui (Daqing Oilfield Co. Ltd.) | Wang, Ying (Daqing Oilfield Co. Ltd.) | Zhang, Jiyuan (Daqing Oilfield Company Limited) | Shan, Guanghao (Daqing Oilfield Co. Ltd.) | Wang, Zhi Yao (Daqing Oilfield Co. Ltd.) | Cao, Tie (Daqing Oilfield Co. Ltd.) | Liu, Chun Gang (Daqing Oilfield Co. Ltd.)


        Based on the MEOR mechanism study of Brevibacillus brevis and Bacillus cereus, From 2002 to 2004, the two strain and other microbes were applied in the microbial huff and puff as well as the Microbial enhanced waterflood test in Daqing excessively low permeability (1.0md-25md) reservoir. After bacteria injection, 44 among the 60 huff and puff wells shows a significant oil production response—the accumulative oil increment reaches 9175.5 tons and the input-output ratio amounts to 1: 8. The Microbial enhanced waterflood test carried out in June 2004 also provides a satisfying result. After the injection of bacteria, the pressure in the two water injectors decreased more than 2MPa, which results in an injection capacity increase. The Analyse result of production fluid indicate that the selected bacteria can adapt the stratum conditions better and can grow and reproduce . They degrade heavy hydrocarbon ,improve character of crude oil and metabolize active substances. The fluid production of  trial field increase and water cut decline . in late 2005 , 7 production wells among 10 production wells get good effect .Fluid production increased from 50.7 tons per day (before bacteria injection) to 68.3 tons per day, and the corresponding water cut declined from 46.8% to 40.3%.oil production is increased from 24.7 tons per day (before bacteria injection) to 40.8 tons per day.The accumulative oil increment more than 5800tons and the input/output ratio is 1:5.  These make MEOR a very promising and effective oil recovery method in Daqing  low permeabilityreservoirs.