胜利油田永8区块原油黏度高、水驱效果差,而且受该区块高温高盐油藏条件影响,常规化学驱技术难以有效提高水驱效率,针对此类问题,笔者开展内源微生物驱油技术研究.内源菌群分析表明,该区块油藏具备了产生物乳化剂、产甲烷气等几种主要功能菌群的条件.筛选并优化出能有效激活内源菌群的激活剂配方.经过激活后微生物的有效浓度达到108个/mL以上,产气压力达到0.088 MPa,最大产气速率达到0.2 L/(g·d)(以1 g激活剂计),柴油乳化指数达到100%,乳化效果48 h内稳定.室内物模驱油评价表明,注入该激活剂配方0.3 PV(孔隙体积)后可提高采收率9%以上,含水率由95.1%下降到81.4%,表现出了良好的应用潜力,为下一步在高温高盐油藏开展微生物驱提供了依据.%At present,conventional technology of chemical flooding is difficult to improve oil recovery in Yong 8 block of Shengli Oilfield because of the high viscosity of the crude oil,high temperature and high salinity of the reservoir condition.Potential application of the endogenous microbial flooding technology was thus studied.Structural analysis indicated that various functional bacteria,e.g.,emulsifier production microbes and methanogen were detected.Several nutritional formulas were then used to activate the bacteria and an optimum one was obtained.The effective concentration of the bacteria in the cultured brothreached 108 cfu/mL and the pressure in the culture bottle reached to 0.088 MPa with an average gas production rate of 0.2 L per gram per day.The activated bacteria broth showed good emulsifying ability,which could emulsify diesel completely and steadily.Core flooding tests showed that the improved oil recovery reached to 14% after 0.3 PV(pore volume) of the activator was injected,and the water cut decreased from 95.1% to 81.4%.The technology of the endogenous microbial flooding might find its application in the test block.
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