摘要
针对高含水中后期油藏以及注水困难的水敏油藏难以实现高效开发与持续稳产的问题,通过PVT釜高压物性实验与长细管驱替实验进行了注富气与CO_2驱提高采收率室内评价研究。实验对原油进行了PVT高压物性分析,研究了注入不同摩尔分数比例的CO_2和富气时,原油饱和压力、降黏效果和膨胀能力的变化规律,并对比分析采用连续注气与交替注气下,高含水油藏的驱油效果。长细管实验对比分析了注CO_2和富气在原油中的最小混相压力及混相驱替效率,CO_2在原油中的最小混相压力为14.27 MPa,富气在原油中的混相压力为34.74 MPa。对原油物性与驱油效率的分析表明,注富气可以较好地提高轻质油藏原油的采收率。与水驱相比,采用连续注气与交替注入,富气驱均可以提高采收率28%以上,且交替注入的效果更好。
The PVT high pressure physical properties of crude oil were tested and analyzed. When various mole fraction proportional CO2 and enriched - gas were injected, it was studied on the change rules in the oil saturation pressure, the vis- cosity - reducing effect, and the swelling capacity. And the displacement effect of high water - cut oil reservoir was compar- atively analyzed under the condition of continuous and water altering gas injections. The research results showed that under the condition of same injected gas volume, compared with CO2 injection, the enriched - gas injection increased the oil satu- ration pressure, but greatly reduce the crude oil viscosity and improve the swelling capacity. Therefore the enriched - gas injection can improve the physical properties of crude oil better. Though the long slim tube experiments, it was comparative- ly analyzed the minimum miscible pressure （MMP） and miscible flooding efficiency of injected CO2 and enriched - gas. The MMP of CO2 and enriched - gas in the crude oil are 14.27 MPa and 34.74 MPa, respectively. The analyses on the physical properties of crude oil and the oil displacement efficiency showed that the enriched - gas flooding could very well enhance oil recovery of light oil reservoir, but for different reservoir characteristics, the effect of enriched -gas flooding on the bubble point pressure should be considered in the process of enriched - gas injection. Compared with water flooding, the enriched - gas flooding can enhance the oil recovery rate of more than 28% with continuous and water altering gas in- jections, and the effect of water altering gas injection was better
出处
《复杂油气藏》
2016年第4期52-57,共6页
Complex Hydrocarbon Reservoirs
基金
中国海洋石油总公司"海上典型底水稠油油藏热采配套工艺技术研究"(CNOOC-KJ 125 2011ZX05024 NFCJF 2012-03)
国家自然科学基金项目"CO2在多孔介质中的扩散速度与前缘位置的研究"(51274217)
关键词
原油物性
CO2驱
富气驱
驱替效率
轻质油藏
physical property
CO2 flooding
enriched - gas flooding
efficiency of displacement
light oil reservoir
