大港孔店油田1区块本源微生物驱油潜力分析

通过分析大港孔店油田1区块油藏物理化学条件,注入水、地层水中微生物种群的组成及硫酸盐还原作用和产甲烷作用的速率来研究该区块进行本源微生物驱油的潜力。利用最大或然法(MPN)对注入水和地层水中的嗜热好氧腐生菌、烃氧化菌、厌氧发酵菌、硫酸盐还原菌和产甲烷菌的数量进行了测定。用放射性同位素方法对硫酸盐还原作用和产甲烷速率进行了分析。结果表明,孔店油田1区块含有多种微生物群落,注入水中嗜热好氧腐生菌105个/mL、烃氧化菌103个/mL、厌氧发酵菌107个/mL、硫酸盐还原菌102个/mL、产甲烷菌1~10个/mL,上述5种微生物数量在生产井中也较高。综合微生物学、油藏条件研究结果,通过激活地层烃氧化菌、发酵菌和产甲烷菌的本源微生物驱提高原油采收率技术在该区块是可行的。

Analysis on Potentiality of Indigenous Microbial Enhancement of Oil Recovery in Block 1 of Dagang Kongdian Oilfield

To investigate physical chemical condition, composition of microbial population, rates of sulfate reduction and methanogenesis in formation water of the block 1 of Kongdian Oilfield to study potential of microbial enhanced oil recovery. The amount of thermophilic aerobic saprotrophs,hydrocarbon-oxidizing bacteria ,anaerobic fermentative bacteria, sulfate-reducing and methanogenic bacteria in injection and formation water were determined by most-probable-number(MPN) method. the sulfate reduction and the rate of methanogenesis processes were analyzed by radioisotopic method. The results show vary microflora inhabited in the block 1 of Kongdian Oilfield. The numbers of thermophilic aerobic saprotrophs and hydrocarbon-oxidizing bacteria in the injection water reached to 10~5 cells/mL and 10~3 cells/mL respectively. The population density of anaerobic fermentative bacteria in the injection water reached to 10~7 cells/mL, and sulfate-reducing bacteria reached to 10~2 cells/mL Methanogenic bacteria were range from 1 to 10 cell/mL. Five kinds of bacteria above were also presented in production wells. So it is possible to enhance oil recovery by activating indigenous microbial of hydrocarbon oxidizing, fermentative bacteria and methanogenic bacteria in this area.