低渗透稠油油藏注气驱室内评价研究

Laboratory evaluation of gas injection flooding in low permeability heavy oil reservoir

某一陆普通稠油油藏因储层渗透率低,常规的化学驱难以实施。针对这一问题,以该油藏条件为基础,通过开展天然气与原油的物性评价实验以及物理模拟实验,研究了注天然气在普通低渗透稠油油藏中的适应性,天然气对原油降黏效果、膨胀性能以及饱和压力的影响,并对驱油效果进行了分析。结果表明:当天然气在原油溶解量为40%左右时,原油黏度由原来的95.18mPa·s降到了53.88mPa·s,同时其体积膨胀了21.2%,极大改善了原油的物性。通过长细管驱油实验,在目标油藏条件下,天然气混相驱时,最终采收率达到90.12%。原油物性与驱油效率的分析结果表明,对于低渗透的普通稠油油藏,注天然气具有很好的应用前景。

It was difficult to carry out the physical and chemical flooding experiment of a heavy oil reservoir with the low permeability.To solve the problem, based on the reservoir conditions, the adaptability of natural gas injection in ordinary low permeability heavy oil reservoir was studied through the physical property evaluation experiment and physical simulation experiment of natural gas and crude oil.The effects of natural gas on the viscosity reduction effect, expansion performance and saturation pressure of crude oil were experimentally studied, and the oil displacement effect was analyzed.The results showed that when the dissolved amount of natural gas in crude oil was about 40%,the viscosity of crude oil decreased from 95.18 MPa·s to 53.88 MPa·s, and its volume expanded by 21.2%.The physical properties of crude oil were greatly improved.Through the long thin tube oil displacement experiment, under the condition of target reservoir, the final recovery rate of natural gas miscible displacement was 90.12%.The analysis of crude oil physical properties and oil displacement efficiency showed that natural gas injection has a good application prospect for low-permeability ordinary heavy oil reservoirs.