苏丹Palogue油田CO2非混相驱室内研究

苏丹Palogue油田主要产层Samaa组为高孔高渗稠油油藏,采用高温高压物理模拟实验研究其注CO2非混相驱驱油效果。给出了非混相CO2驱开采稠油的主要机理,对连续注CO2驱替、单一CO2段塞驱替进行了试验,对CO2连续驱驱油效率、注入压力、气体消耗量、CO2回收利用进行了分析。研究表明,CO2连续驱可以取得可观的驱油效果,采收率最高达到70.2%;使用CO2单一段塞驱油的最终采收率高于连续驱,其最佳段塞大小为0.625PV,最终采收率为89.4%。综合考虑该区块适合采用CO2非混相驱替方式进行采油,单一段塞驱替效果更好,采油过程中,应该合理地控制地层压力。

Laboratory study of immiscrible CO2 drive in the Great Palogue Oilfield in Republic of Sudan

Samma formation in Great Palogue Oilfield,Block 3/7 of Republic of the Sudan was high porosity and high permeability heavy oil reservoir.The CO_2 immiscible drive mechanism,injection mode and injection volume were studied by using the high-temperature high-pressure experimental system,and the recovery efficiency,injection pressure,gas consumption and CO_2 recycling usage were analyzed.The result shows that CO_2 continuous drive can get a considerable effect with a ultimate recovery rate of 70.2%.The single CO_2 slug injection can get higher oil recovery rate than continuous injection,and the best injection volume is 0.625 PV with a recovery rate of(89.4)%.It is suitable to develop the reservoir by CO_2 immiscible drive with single slug injection.At the same time,formation pressure should be maintained rationally.