Papers by Keyword: Indigenous Microorganism

Abstract: The residual oil in situ microbial gasification technology is a new method to extend the life of oil reservoir, which means using the microbial to transform petroleum hydrocarbons into methane under anaerobic conditions, then the oil reservoir can be exploited or stored in situ. 50ml samples were added to 120ml sterile anaerobic bottle, at the same time, residual oxygen was removed under a gentle stream of high purity nitrogen by Hungate, then the bottle was filled tightly with rubber stoppers to remain strictly anaerobic state. These samples were placed in the incubator in dark condition. 100 days later, methane was detected by gas chromatography analyzing headspace gas, so it is used as inoculum for enrichment culture. 5ml inoculum above mentioned was added to the oil reservoir conditions simulated reactors. The ones with 10ml crude oil sample is (Y), the ones without crude oil sample is (N), at the same time, 10ml inorganic salt culture medium was added to each reactor.

Abstract: In order to utilize the beneficial Indigenous Microbial in objective reservoir, active formula systems with various nutriment components were investigated^[. The results of performance evaluation showed that the activation, emulsification, viscosity break, and oil displacement performance of nutritional formula system were approved. Based on the field verification, the beneficial Indigenous Microbial in produced fluid of post treatment well array was activated, oil quality was improved, displacement efficiency was advanced, and oil production was increased.

Abstract: The molecular ecology analysis of microorganisms is important for the development of microbial enhanced oil recovery. The bacterial 16S rRNA gene clone library was constructed to detect the community diversity in injection-water and produced-water in Luliang Oil field in Xinjiang in this study. The phylogenetic analysis indecated that most of clones (76%) in injection-water were clustered in α-proteobacteria. Roseovarius sp. and Novispirillum sp. were the main bacteria accounting for 41.3% of the total of clones. And the most clones in production water were clustered in α,γ-proteobacteria with the phylotypes belonging to α-proteobacteria accounting for 61% of the clone library. Sphingomonas sp. and Pseudomonas stutzeri sp. were the dominant bacteria which constitute 26% and 22%. The variaty of functional bacteria is more in produced-water than injection-water.

Abstract: The feasibility of enhancing oil recovery in Xinjiang oilfield with heavy oil reservoir was studied. The results showed that main microbial populations in the reservoir were saprophytic, hydrocarbon-oxidizing, nitrate-reducing bacteria, sulfate-reducing bacteria, and fermentative. Given optimized carbon and nitrogen sources, the indigenous microorganisms generated gases, which mostly were CO₂, and amount of gases could reach 1.3 times volume as nutrient solution. The effect of MEOR was evaluated by a sand pack experiment, and the oil recovery was 9.5%. The test with the injection of nutrient and air was carried out. Field performance monitoring and product ion tracking results showed: 1the indigenous microorganisms were activated with the number increased 2-3, and microbial population structure changed apparently; 2The content of CO₂ and CH₄ in the gas of oil well changed slightly; 3the properties formation water were changed, the content of HCO₃^- in formation water varied greatly, and emulsion were found. 4Although Indigenous Microbial Flooding Technology may be a potential technique for the development of oilfields, that biogas generated by microbes is not the primary mechanism of Indigenous Microbial Flooding Technology is determined.

Abstract: Biotechnological nutrient flooding was applied to the North block of the Kongdian Oilfield during 2001-2005. The biotechnology involved the injection of a water-air mixture made up of mineral nitrogen and phosphorous salts with the intent of stimulating the growth of indigenous microorganisms. During monitoring of the physico-chemical, microbiological and production characteristics of the North block of the Kongdian bed, it was revealed significant changes took place in the ecosystem as a result of the technological treatment. The microbial oil transformation was accompanied by an accumulation of carbonates, lower fatty acids and biosurfactants in water formations, which is of value to enhanced oil recovery. The microbial metabolites changed the composition of the water formation, favored the diversion of the injected fluid from closed, high permeability zones to upswept zones and improved the sweep efficiency. The results of the studies demonstrated strong hydrodynamic links between the injection wells and production wells. Microbiological monitoring of the deep subsurface ecosystems and the filtration properties of the fluids are well modified, producing 40000 additional tons of oil in the test areas.

Abstract: To successfully simulate the anaerobic metabolic process of Indigenous Microbial Enhanced Oil Recovery (IMEOR) and reduce the risk of practice test, a new mathematical model was established for porous flow field-microbial field coupling in anaerobic metabolic process according to the study on anaerobic microbe chain composed of fermentative bacteria, nitrate reducing bacteria, sulfate reducing bacteria and methanogen, and the solution of this model was given. The effect of IMEOR in anaerobic metabolic process relies on the regulation of microbe community. Equations about porous flow field affected by microbe in the model not only elaborate the impacts of microbe and three primary metabolic products (bio-surfactant, bio-polymer, bio-gas) on physical parameters, but also reflect the main mechanisms (emulsification, profile modification and viscosity reduction) for microbial enhanced oil recovery. Equations in microbial field influenced by fluid flow could indicate the substance distribution decided by fluid flow and the collaborative metabolism relationship on biological chain formed by microbe community. The coupling of porous flow field and microbial field should be solved together. The model supplies theoretical basis for the study on IMEOR mathematical model software.