高温高压条件下微生物驱油微观机理研究

Microscopic Mechanism Studies on Microbial Enhanced Oil Recovery under High Temperature High Pressure Reservoir Conditions

采用微观透明可视仿真刻蚀储层模型,研究了3株产表面活性剂较多的好氧菌W18、DM-2和SH-1,2株产生物气较多的厌氧菌L1、4F,在高温高压条件下(65℃,10 MPa)驱油时形成的残余油状态,结合大量微观照相图讨论了驱油机理。5株菌在高温高压油藏中均能存活,驱油性能较好。生物气驱机理包括:气驱,气液界面滑动,原油膨胀降黏,气泡贾敏效应扩大水驱波及体积及气体进入盲端驱油。生物表面活性剂驱油机理包括:乳化分散剩余油,降低油水界面张力,剥离油膜。微生物降解原油也是驱油机理之一。图28表1参4。

3 aerobic biosurfactant producing bacteria W18, DM-2 and SH-1 and 2 anaerobic biogas producing bacteria L1 and 4F are studied for their EOR performance in visible transparent etched reservoir-simulating micromodels under high temperature high pressure reservoir conditions, 65℃ and 10 MPa, the various states of remained oil are presented and the mechanisms involved in oil displacement are discussed with the help of lots of photographs. The 5 bacterial strains all survive in the experimental micromodels and behave rather well as EOR agents. The oil displacement mechanisms by biogases cover gas driving, oil droplet slippage along gas-liquid interfaces, dilation and viscosity reduction of oil, Jamming effect of gas bubbles enhancing volume sweeping, and gas entering and driving oil out of a dead pore end. The oil displacement mechanisms by biosurfactants cover emulsifying and dispersing remained oil, reducing oil/water interracial tension, and debonding adhered oil film. Biodegradation of crude oil by microbes is also involved in oil displacement as an important factor.