油藏中后期减氧空气驱提高采收率机理研究

尕斯库勒油田E¹₃油藏已经进入高含水时期，储采失衡加剧，综合含水率达到了80%以上，原油产量下降，经济效益变差。为了提高油藏原油采出程度、改善油藏开发效果，调研了国内外减氧空气驱的机理研究以及现场试验的资料，建立了以油藏真实孔渗饱数据为基础的一维条形地层机理模型，并选取该油藏Y12-27井组进行了减氧空气驱可行性验证。研究表明:纵向顶部减氧空气驱驱油效果优于水驱和氮气驱；驱替压力对原油采出程度影响不大；注水转注气可以提高原油采出程度；对于减氧空气驱，由于低温氧化反应的作用，氧气浓度对原油采出程度有一定影响，但比较微弱，其中，氧气浓度为10%时，驱替结束采出程度最高；尕斯库勒油田E¹₃油藏属于注水开发“双高”油藏，适用于减氧空气驱；对于该油藏Y12-27井组，顶部减氧空气驱驱油效果好于水驱和氮气驱，建议氧气浓度超过10%时采取关井等措施。

Research on mechanism of enhanced oil recovery by oxygen-reducing air flooding in middle and late stage of reservoir development

Gasi Kule E 13 Reservoir has entered the period of high water cut,the imbalance between storage and production has been aggravated,the comprehensive water cut has reached more than 80%,the crude oil output has decreased,and the economic benefit has become worse.In order to improve the degree of crude oil production and the development effect of the reservoir,the research on the mechanism of oxygen reducing air flooding at home and abroad and the data of field tests were investigated,and a one-dimensional strip formation mechanism model based on the data of true pore saturation of the reservoir was established,and the feasibility of oxygen reducing air flooding was verified by selecting the group of Wells Y12-27 in the reservoir.The results showed that the oil displacement effect of vertical top oxygen reducing air drive is better than that of water drive and nitrogen drive.The displacement pressure has little effect on the degree of oil production.The degree of oil production can be improved by injecting water into gas.For oxygen-reducing air flooding,due to the effect of low-temperature oxidation reaction,the oxygen concentration has a certain influence on the degree of oil recovery,but it is weak.Among them,when the oxygen concentration is 10%,the degree of oil recovery at the end of displacement is the highest.The Gasi Kule E 13 reservoir belongs to the"high water cut and high recovery degree of recoverable reserves"reservoir which is developed by water injection and is suitable for the deoxidized air flooding.For the group of Wells Y12-27 in this reservoir,the top oxygen-reducing air flooding has better oil displacement effect than water flooding and nitrogen flooding,and it is recommended to take shut-in measures when the oxygen concentration exceeds 10%.