邵家油田沾3 块内源微生物驱激活剂优化及现场试验

内源微生物驱是通过向油藏注入适当的激活剂,选择性地激活油藏中已有的微生物,实现微生物驱油。因此激活剂选择和优化对内源微生物驱来说至关重要。在对胜利油区沾3块油藏地质分析的基础上,分别以淀粉水解液为碳源、硝酸钠为氮源、磷酸氢二铵为磷源,以沾3-斜24井产出水作为激活对象,首先利用静态激活实验从微生物活性角度初步确定出2组激活剂配方;然后利用动态物理模拟对2组配方进行微生物群落动态变化规律及增油效果评价实验,最终优化出沾3块内源微生物驱最佳激活剂配方为0.3%淀粉水解液+0.2%(NH4)2HPO4+0.2%NaNO3,该配方物理模拟实验提高采收率平均大于6.7%。在胜利油区沾3块3口油井进行了单井吞吐现场试验,试验后单井平均日增油量为1.2t,含水率平均下降3.5%,见效周期超过3个月,截至2011年3月底累积增油量超过4000t。

Experimental study on activator optimization of indigenous microor ganisms flooding and field tests in Zhan3 block,Shaojia oilfield

Indigenous microorganism flooding means that proper inactivator is injected into the oil reservoir,and selectively activates original microorganisms in the oil reservoir in order to realize the microorganism flooding.Therefore it’s significant to choose and optimize inactivator to indigenous microorganism flooding.On the basis of the analysis on Zhan3 block reservoir status in Shen-gli oilfield,using amylolysis as carbon source,NaNO3 as nitrogen source,(NH4)2HPO4 as phosphorus source,we produce water from Zhan3-x24 well as activated object,different activator systems’ activation effect on indigenous microorganisms is studied by static experiment combined with dynamic experiment in this paper.Firstly,in terms of microbial activity,two activator systems are preliminarily ascertained by static physical model test.Then,microbial community dynamic change rule and oil incremental effect evaluation experiment are carried on this two activator systems by dynamic physical model test to optimize indigenous microorgan-isms flooding optimum activator system in Zhan3 block which is amylolysis 0.3%,(NH4) 2HPO4 0.2% ,NaN03 0.2%.Finally,the result of single well stimulation by indigenous microorganisms flooding field tests in 3 wells in Zhan3 block indicates that this new technology has been increasing oil production per well by 1.2 t/d,average water content has been decreased by 5.5% ,re-sponse cycle has exceeded 3 months,cumulative stimulation ratio has reached more than 4 000 tons at the end of March,2011.