Investigation of biosurfactant-producing indigenous microorganisms that enhance residue oil recovery in an oil reservoir after polymer flooding.
Three biosurfactant-producing indigenous microorganisms (XDS1, XDS2, XDS3) were isolated from a petroleum reservoir in the Daqing Oilfield (China) after polymer flooding. Their metabolic, biochemical, and oil-degradation characteristics, as well as their oil displacement in the core were studied. These indigenous microorganisms were identified as short rod bacillus bacteria with white color, round shape, a protruding structure, and a rough surface. Strains have peritrichous flagella, are able to produce endospores, are sporangia, and are clearly swollen and terminal. Bacterial cultures show that the oil-spreading values of the fermentation fluid containing all three strains are more than 4.5 cm (diameter) with an approximate 25 mN/m surface tension. The hydrocarbon degradation rates of each of the three strains exceeded 50%, with the highest achieving 84%. Several oil recovery agents were produced following degradation. At the same time, the heavy components of crude oil were degraded into light components, and their flow characteristics were also improved. The surface tension and viscosity of the crude oil decreased after being treated by the three strains of microorganisms. The core-flooding tests showed that the incremental oil recoveries were 4.89-6.96%. Thus, XDS123 treatment may represent a viable method for microbial-enhanced oil recovery.
She
Yue-Hui
YH
College of Chemistry and Molecular Sciences, Wuhan University, China. sheyuehui@yahoo.com.cn
Zhang
Fan
F
Xia
Jing-Jing
JJ
Kong
Shu-Qiong
SQ
Wang
Zheng-Liang
ZL
Shu
Fu-Chang
FC
Hu
Ji-Ming
JM
D001407:Bacillus / Q000145:classification / Q000302:isolation & purification / Q000378:metabolism*; D001709:Biotechnology; D002681:China; D005285:Fermentation; D005407:Flagella / Q000502:physiology; D006838:Hydrocarbons / Q000378:metabolism; D010578:Petroleum / Q000382:microbiology*; D011108:Polymers / Q000737:chemistry; D058432:Sporangia / Q000502:physiology; D013500:Surface Tension; D013501:Surface-Active Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D014783:Viscosity
D006838:Hydrocarbons; D010578:Petroleum; D011108:Polymers; D013501:Surface-Active Agents