PBS菌的趋化性与提高原油采收率机理  

Chemotaxis and Mechamisms in Microbial Enhanced Oil Recovery by Using Bacteria PBS

作　　者：吴柏志[1] 李宜强[2] 张琪[3] 张艳君[4] 

机构地区：[1]中国石化胜利油田公司井下作业三公司,山东东营257237 [2]大庆石油学院石油工程学院,黑龙江大庆163318 [3]石油大学华东石油工程学院,山东东营257061 [4]中国石化胜利油田公司桩西采油厂,山东东营257237

出　　处：《油田化学》2004年第4期372-375,390,共5页Oilfield Chemistry

基　　金：中国石油股份有限公司重点科技攻关项目"微生物采油技术研究"(030121 1)资助。

摘　　要：实验验证了PBS菌的趋化性,在物理模型上考察了PBS菌的驱油机理和效果。PBS菌为假单胞杆菌属,兼性厌氧,可利用原油为碳源生长,代谢产物主要为化学结构已确认的一种鼠李糖脂,以及少量脂肪酸、有机醇、气体等。菌液中PBS菌数105～106个/mL,培养温度51℃,实验原油51℃下粘度35 2mPa·s,驱替水矿化度3 7g/L。在显微镜载玻片上培养0 5天后,距油水界面10μm以内的水相(菌液+营养液)中菌数达108个/mL,2天后更达109个/mL,而在10μm以外的水相中仅为103个/mL。在玻璃盒内培养0 5天后,靠近油水界面处水相中菌数为109个/mL,pH值4 4,鼠李糖脂浓度2 87g/dL,距油水界面10、20、30mm处水相中,菌数分别为107、106、105～104个/mL,形成细菌浓度分布梯度。以上实验结果用细菌的趋化性解释。在仿真网络模型上,水驱油后注入1PV菌液+营养液,51℃培养10天后再水驱,观察并记录了以下驱油机理:①乳化携带,启动剩余油;②剥离油膜或油团;③堵塞大孔道,液流转向。在渗透率1μm2的板状填砂模型上水驱油采收率为48%,注入1PV菌液+营养液,在51℃培养10天后再水驱,提高采收率13 6%。图12参6。The chemotaxis of bacteria PBS is experimentally evidenced and the mechanisms involved and the results of MEOR by using bacteria PBS are studied on physical models. PBS of Pseudmonas spp. are facultative, can utilize crude oils as carbon source and metabolize mainly a rhamnolipid of identified chemical structure and a little amount of fatty acids, alcohols, and gaseous products,etc. The concentration of the bacterial culture 10~5-10~6 cells/mL; the temperature of cultivation 51℃, the viscosity of the crude oil used 35.2 mPa·s(51℃) and the total salinity of the water used in core flow experiments 3.7 g/L. Being cultivated on a sample glass for microscope, the population of PBS in aqueous phase (bacterial culture+nutrients) in the zones within 10 μm apart from the O/W interface reaches 10~8 cells/mL in 0.5 day and 10~9 cells/mL in 2 days while the PBS population in other zones is of 10~3 cells/mL only. Being cultivated in a glass box in 0.5 day, PBS population in aqueous phase 10~9 cells/mL, pH value 4.4 and rhamnolipid concentration 2.87 g/dL are observed in zones near the O/W interface and PBS population in the zones 10,20,and 30 mm apart from the O/W interface is of 10~7,10~6, and 10~5-10~4 cells/mL, respectively, that is, a gradient of bacterial population appears. The phenomena are explained in terms of the chemotaxis of bacteria. On a microscopic two-dimensional porous medium model following oil-displacing mechanisms are observed after water flood, injection of 1 PV of bacterial culture+nutrients and cultivation at 51℃ in 10 days in the course of successive water flood: ① emulsifying, carrying and starting-up of immobile residual oil; ② stripping of oil film or cluster; and ③ plugging of big channellings and fluid diverting. On a plate-like sand pack of permeability 1 μm^2 48% oil recovery is obtained by water flood and an enhancement in oil recovery 13.6% is obtained by injection of 1 PV bacterial culture+nutrients and cultivation at 51℃ in 10 days followed by water flood.

关 键 词：提高原油采收率 PBS 趋化性 油水界面 驱油机理 鼠李糖脂 假单胞杆菌 营养液 物理模型 兼性厌氧 化学结构 代谢产物 培养温度 水矿化度 浓度分布 网络模型 水驱油 菌数 菌液 水相 实验 脂肪酸 有机醇 显微镜 pH值 剩余油 

分 类 号：TE357.46[石油与天然气工程—油气田开发工程] TP301.6[自动化与计算机技术—计算机系统结构]