聚合物驱后利用微生物进一步提高采收率的可行性

Feasibility of MEOR after polymer flooding

大庆油田聚合物驱工业化推广应用取得了显著的经济效果,比水驱提高采收率10％(OOIP)以上。目前年产油量已突破千万吨,成为油田可持续发展的重大技术措施。尽管如此,聚合物驱后油层中仍剩有50％左右的原油未被采出,如何开采这部分剩余油是油田开发面临的主要问题之一。为此,针对大庆油田聚合物驱后油藏的物化环境,筛选出了以聚合物和原油为营养源的菌种,并对其性能进行了系统的评价。物理模拟驱油实验结果表明,聚合物驱后单独微生物驱可提高采收率5％,微生物与化学驱结合可提高采收率16％。

Great advancement has been achieved with polymer flooding after water flooding to enhance oil recovery in Daqing oilfield and the test scale has been changed from pilot test to industrialized application. However, there is still about 50% remaining oil kept in oil-bearing formation after polymer flooding. To do with the remaining oil, this paper gives the method of quarternary oil recovery by using MEOR succeeding a polymer flooding. In our studies, the microorganisms that can grow with partially hydrolyzed polyac-rylamide (PHPA) and crude oil as the nutritional source has been screened. These microorganisms can produce and metabolize as well as enhancing oil recovery under the special formation condition that polymer flood has been completed. This paper also gives evaluation on the physiological and bio-chemical characteristic of the screened bacterium and on the effect of oil displacement. The physical simulation of core displacement test shows that oil recovery can be improved 5% to 16% (OOIP) by using MEOR after polymer flooding.