致密油藏注CO_(2)吞吐技术研究

Study on CO_(2) huff and puff technology in tight reservoir

我国致密油储量丰富,而致密油储层油气饱和度低,孔喉窄,物性差。即使水平井压裂作业后,采收率仍然很低,必须进行地层能量补给。此外,地层能量由注水开发补充,往往会产生“注不进、采不出”与水窜等问题。如果能够将CO_(2)吞吐作为一种高效开发方式广泛应用于现场作业,一方面可以有效提高致密油采收率,解决现有开发技术上的诸多不足,实现经济效益;另一方面,在回收二氧化碳的同时,也可以缓解其大量排放造成的环境压力,符合中国可持续发展战略的要求。本文通过调查大量文献,综述了致密油藏注CO_(2)吞吐国内外研究现状,总结了CO_(2)吞吐机理,同时对吞吐效果的影响因素进行了分析,为CO_(2)吞吐研究提供理论依据与方向。

China is rich in tight oil reserves,while tight oil reservoirs have low oil saturation,narrow pore throat and poor physical properties.Even after horizontal well fracturing,the recovery is still very low,and the formation energy must be supplied.In addition,the formation energy is supplemented by water injection development,which often leads to problems such as not injecting,not producing and water channeling.If CO_(2)huff and puff can be widely used as an efficient development method in field operations,on the one hand,it can effectively improve tight oil recovery,solve many deficiencies in existing development technologies,and achieve economic benefits.On the other hand,the recovery of carbon dioxide can also alleviate the environmental pressure caused by its large emissions,in line with the requirements of China's sustainable development strategy.In this paper,through the investigation of a large number of literature,the research status of CO_(2)huff and puff in tight reservoirs at home and abroad is reviewed,the mechanism of CO_(2)huff and puff is summarized,and the influencing factors of huff and puff effect are analyzed,to provide theoretical basis and direction for CO_(2)huff and puff research.