Potential of indigenous microbial enhanced oil recovery in N3 block of Gangxi oilfield

Potential of indigenous microbial enhanced oil recovery in N3 block of Gangxi oilfield is studied through analyzing the physico - chemical conditions, microbial populations, sulfate reduction and rate of methanogenesis in formation water. N3 block of Gangxi oilfield have various microbial populations, such as hydrocarbon - oxidizing bacteria that produce surfactants, anaerobic fermentative bacteria that generate gas, acid, solvent and biopolymer and methanogens that produce methane. Infrared spec-troscopy that are performed before and after indigenousbacteria acting on crude oil show that the structures of aromatic hydrocarbons in crude oil change greatly. Based on the comprehensive study results of microbiology and re-serviring conditions, it is believed that indigenous microbial enhanced oil recovery through activating the hydrocarbon - oxidizing bacteria, anaerobic fermentative bacteria and methanogens is practical in this block.