Investigation of Biosurfactant-Producing Indigenous Microorganisms that Enhance Residue Oil Recovery in an Oil Reservoir After Polymer Flooding

Abstract

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.

Microbial-Enhanced Heavy Oil Recovery under Laboratory Conditions by Bacillus firmus BG4 and Bacillus halodurans BG5 Isolated from Heavy Oil Fields

“…The most abundant compound present during the ninth day of incubation was hexadecanoic acid (RT 14.87) for B. firmus and dodecane (RT 12.42) for B. halodurans (Tables 2 and 3). Bacteria from the oil fields in Japan and China degrading n-alkane were reported [33,61]. B. firmus and B. halodurans in this study showed fractionation of higher n-alkanes having carbon numbers up to C 54 .…”

Richness of drilling sludge taken from an oil field quagmire: potentiality and environmental interest

“…It is known that HDB release surfactants or emulsifiers in order to facilitate assimilation of insoluble substrates such as crude oil (Bucheli-Witschel and Egli 2010); indeed, biosurfactants are structurally diverse amphiphiles that are secreted in the environment to facilitate the diffusion and uptake by microorganisms of hydrophobic substances from aqueous media (Lawniczak et al 2013). Biosurfactant-producing microbes are found in various ecosystems, especially in those polluted with hydrophobic contaminants, such as petroleum wastes which are more yielding than undisturbed environments (Belcher et al 2012;She et al 2011). The bioavailability of petroleum products to microorganisms of oil-degrading community is considerably affected by biosurfactants, which isolate individual petroleum molecules in micelles (Belcher et al 2012).…”

Research Status of Surfactant Producing Microbiology in MEOR: A Review

“…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 ranged from 4.89% to 6.96% ( She, 2011). The biosurfactant production of two surfactant producing bacteria HD-322-2 and T103 is 321mg/L, and 195mg/L, respectively.…”