Study Of Microbiology Ecology In Oil Reservoir

With the rapid technological development of Microbial Enhanced Oil Recovery (MEOR), it has demonstrated a good view and attracted more global attentions. While the advantages of this technology is still far from totally performed. One of the main reasons is the lack of knowledge on the microbial communities and their functions. The purpose of this dissertation is to determine the application range of MEOR and to supply theories for pilot test. Then, the evaluation and the molecular detection of microorganism in oil reservoirs at different temperature were carried out.The methods based on 16S rDNA, which were mainly denaturing gradinent gelelectrophoresis and Terminal-restriction fragment length polymorphism, were performed to acquire the spices and heritage diversity of reservoir microorganism.The microorganism community in 54℃, 66℃, 78℃and 85℃oil reservoirs were tested by the methods established before. The results showed that all the above reservoirs had microorganism activities. The quantitative and spice of microorganism had no direct relationship with the temperature of reservoirs. The application range of MEOR was determined on the basis of the results above-mentioned and the characteristics of reservoirs and production.The microbial ecology in oil reservoirs after polymer flooding were analyzed, and the results showed that the spices and quantitative in those reservoirs were abundant, which made MEOR possible in oil reservoirs after polymer flooding.The diversity and quantitative of microorganism in block L801 decreased and increased, respectively, after MEOR treatment, and the oil production increased apparently. It is demonstrated that the balance in reservoir was broken by man-made interference, followed by production increase. And the block Shan 12 had formed a new ecological balance after MEOR treatment by competition, inhabitation and symbiosis. A new spice, Pseudomonas sp., has became dominate in 12 months, which is capable of degrading hydrocarbon and increasing oil production.