Screening Of Strains For Microbial Combination Flooding And Evaluation Of The Effect For Heavy Oil Fields

With the rapid development of national economy in our country, the demand for oil resources in the economic construction is increasing. Though the scale of the exploration is increasing, The chance to finding a large fields is smaller and smaller. Heavy oil as an important reserve resources in the21st century has an important impact on the economy. The heavy oil resources of our country is very rich. With the development of heavy oil was intensified, the study of heavy oil is increasing. The economic construction of our country depends on the development of petroleum industry, this needs to study how to develop the heavy oil resource of our country better, this has far-reaching significance in the nervous case of heavy oil reserves. MEOR technique was using microbial metabolic activities and its metabolites acted on reservoir and reservoir fluid to realize EOR, and had the features of lower cost, fine applicability, simple construction, no damage to reservoir and no environmental pollution, etc. This had already caused the petroleum engineers’attention, and was an economy effective means of exploiting low yielding and inefficient oilfield, and had given initial results in field test at home and abroad.The studied development experimental oilfield in this article had typical characteristics of heavy oil field and low recovery, so the pressing need was to seek an EOR technology with low cost, high effect. The EOR technology could realize the target of high and stable product and sustainable development of oilfield. This article based on the study of adaptability of microbial strains and oilfield environment, select microbial strains suitable for heavy oil fields, to optimize the culture medium formula and fermentation conditions, combined with the indoor physical simulation experiment to explore the suitable microbial flooding mode for heavy oil field.According to the reservoir formation condition of the test field, a primitive strain releasing bio-surfactants, a primitive strain degrading petroleum hydrocarbon and an exogenous strain releasing biopolymer were separated and screened, and the three strains were identified. Then, the article researched growth and metabolism of those three strains. The result showed that those three strains could adapt to heavy oil field. For different strains, the compatibility of nutrient medium was studied, the results proved that those three strains could grow up nomally. Through the physical simulation experiment research the influence of microbial concentration, dosage and so on. That proved that those three strains play an important synergy for improve the recovery efficiency, the effect of MEOR was obvious after water flooding.