摘要: 由于原油黏度高，边底水稠油油藏油水流度比大，单井含水上升快，导致该类油藏采出程度低。探索边底水油藏微生物复合氮气吞吐工艺，扩大微生物的作用半径，提高微生物与剩余油接触和动用效率，从而实现单井产量提高。首先建立 乳化降黏和润湿洗油的微生物复合吞吐体系，0.3%复合体系表面张力为27.5mN/m，洗油效率为91.3%，原油降黏率达83.7%；该体系与氮气复合后具有一定的泡沫性能。利用一维物理模拟实验优化微生物体系与氮气复合注入工艺，气液比为2，注入浓度为0.3%，焖井周期为10d；采用微生物氮气复合吞吐工艺在弱边底水油藏现场试验了6口井，平均含水降低10%以上，增油达8 494t，取得了良好的矿场试验效果。
关键词: 边底水；稠油；微生物；氮气；吞吐工艺

Abstract:

Due to its high viscosity, heavy oil reservoirs with edge/bottom water often have a low recovery ratio due to its high oil-to-water flow ratio and rapidly rising water cut of single wells. By exploring the microbial composite nitrogen stimulation process in heavy oil reservoirs with edge/bottom water, it aims to expand the working radius of microorganisms and improve their contact and efficiency with residual oil, so as to increase single-well production. First of all, a microbial composite stimulation system of hydrophilic emulsification viscosity reduction and wetting oil washing system is set up, with a 27.5mN/m surface tension on the 0.3% composite system, 91.3% oil washing efficiency, and 83.7% viscosity reduction rate of crude oil. This system has certain foaming property when in composite with nitrogen. The composite injection process of nitrogen into microbial system is optimized through a one-dimensional physical simulation experiment, with the gas-liquid ratio at 2, the injection concentration at 0.3%, and the period of well stewing for 10 days. After testing the microbial nitrogen composite stimulation process on six wells in a weak edge/bottom water reservoir, it’s found that the average water content is reduced by over 10%, and oil output goes up by 8,494t, achieving sound field testing effects.

Keywords: edge/bottom water; heavy oil; microorganism; nitrogen; stimulation process