罗801区块油藏环境厌氧微生物链的形成及其对微生物驱采收率的影响

Anaerobe Chain Formation in Reservoir Environment and Its Relation to Enhancement in Oil Recovery by Cyclic Microbe Injection in Block L801

概述了油藏厌氧生境中的厌氧微生物链并给出图解式。根据胜利罗家油田罗 80 1区块微生物驱油试验中的监测数据 ,注入驱油菌BS、FM及营养物质后 ,试验区产出水中水解菌、产氢产乙酸菌、反硝化菌、产甲烷菌、同型产甲烷菌的总菌数由 10 0 ～ 10 7个 /mL增加到 10 3 ～ 10 4个 /mL ,乙酸根浓度由 2 1.8mg/L增加到 4 0 0mg/L以上。由此推断 ,注入的水解类菌BS和FM及营养物质激发了油藏中各类厌氧菌的活性 ,通过各类菌群的繁殖代谢 ,形成了新的厌氧微生物链。该微生物链的首端为注入油藏的和油藏中原有的水解菌 ,以产氢产乙酸菌、反硝化菌、同型产乙酸菌为中间阶段 ,末端为产甲烷菌 ,给出了该厌氧微生物链的图解式 ,讨论了链中一些微生物的生长代谢、相互作用及驱油作用。介绍了罗 80 1区块微生物驱油试验的结果 :产油量递减率控制在 5 %以内 ,年产油量稳定在4 .4× 10 4t以上 ,平均年增产油量 1.2 7× 10 4t ,采收率已提高 2 .11% ,预计最终可提高采收率 5 .6 6 %。图 7表 1参5。

A typical anaerobe chain commonly exited in oxygen-free reservoir environments is introduced and its schematic diagraph is presented. According to the monitoring data from the experimental area of cyclic microbe injection program in block L801 of Luojia, Shengli, the total microbial population of hydrolytic, hydrogen-producing/acetogenic, nitrate-reducing, methane-producing,and homoacetogenic bacteria in the produced water increases from 10~0-10~1 cells/mL to 10~3-10~4 cells/mL and the acetate concentration - from 21.8*'mg/L to more than 400 mg/L and it is concluded from these data that the microbes notated as BS and FM, being hydroliticus, injected into the reservoir formations together with nutrients activate various kinds of reservoir anaerobes and the growth and metaboly of all these anaerobes build up a new anaerobe chain, starting from the bacteria hydrolyticus both injected and in place through hydrogen-producing/acetogenic, sulfate-reducing, and homoacetogenic bacteria as intermediate phases and being terminated with methane-producing bacteria. The schematic diagraph of the anaerobe chain is presented and the metabolic activities, interactions and functions in oil-displacement of some bacteria in the chain are discussed. The results of cyclic bacteria injection program in block L801 are presented in terms of following data: composite decline rate of oil productivity controlled within 5%; annual oil production kept stable and acconting >4.4×10~4 tons with average increment of 1.27×10~4 tons; enhancement in oil recovery of 2.11% (OOIP) reached and of 5.66%(OOIP)at the end of the program predicted.