低渗透裂缝性油藏微生物调驱室内研究

Laboratory study on microbial profile control for oil displacement in low-permeability fractured reservoir

低渗透油藏主要开发技术是在强化地质认识基础上,以酸化压裂、完善井网、细分开采、丛式井配套为主的水驱技术,由于天然裂缝发育,在注水开发过程中呈现出油井产水快速上升、产能下降、供液能力差、低产低效的局面。为改变这种局面,对延长油田唐80区从54井组微生物调驱进行室内评价研究。微生物采油是一种经济有效的技术,是油田开发后期一种重要的提高采收率技术。针对井组油藏的特点,根据微生物驱提高采收率技术路线,对菌种进行筛选及评价,对初步筛选的2种微生物菌种在室内进行了基本性能评价,并进行微生物菌液物理模拟实验,综合评价和研究驱油技术提高采收率的能力。实验结果表明,利用微生物对该类油藏进行调剖驱油,能明显改善注采状况,对区块起到降水增油的作用。为更好地在低渗透性油田应用微生物采油技术,提供了经验和依据。

The main technology for developing low permeability reservoir is waterflooding which involves acid fracturing, well pattern completing, subdivided producing and cluster well supporting based on enhanced geological understanding. Because of developed natural fractures, water production increases rapidly, productivity decreases, and feed flow capability is poor, showing low production and low efficiency in waterflooding process. Microbial profile control for oil displacement has been evaluated and studied in laboratory for Cong 54 well group in Tang-80 block of Yanchang Oilfield. MEOR is an effective method for the late life of oilfield development. Microbial strains are screened and evaluated according to reservoir characteristics. Two strains which are preliminarily screened are evaluated for basic performance in laboratory. Physical simulation is conducted with bacterial cultures to comprehensively evaluate and study MEOR ability. Experiment result shows that microbial profile control for oil displacement in low permeability reservoir can improve injection and production performance, reduce water production and increase oil production.