摘要
吉木萨尔凹陷芦草沟组页岩油具有原始渗透率极低,原油黏度高等特点,自然条件下无经济产能。通过现场实践,证明密切割+高强度体积压裂,是实现页岩油规模开发的最有效手段之一,但现阶段如何延缓油井递减率,提高单井采收率仍是亟待解决的问题。2019—2022年,在吉木萨尔页岩油区块,开展了CO_(2)前置压裂辅助提产技术研究和现场试验,系统地研究分析CO_(2)前置蓄能压裂和CO_(2)吞吐在吉木萨尔页岩油区块的应用效果。结果表明,超临界态CO_(2)具有混相增能、溶蚀改善储层条件、提高渗吸置换效率、提高缝网复杂程度等作用,并明确最优注入量、注入速度、注入方式等关键工艺参数,初步形成了一套页岩油藏CO_(2)前置压裂的工艺技术体系。根据生产数据预测,CO_(2)前置压裂工艺可将最终采收率提升20%左右,对实现页岩油效益开发,为其他类型页岩油藏提高开发效果提供参考。
The shale oil of Lucaogou Formation in Jimsar Sag has the characteristics of extremely low original permeability and high viscosity of crude oil,making it uneconomical to produce under natural conditions.Field practices have demonstrated that dense drilling combined with high-intensity volume fracturing is one of the most effective means to achieve large-scale development of shale oil.However,how to slow down the decline rate of oil wells and improve the recovery rate per well remains a pressing issue to be addressed.From 2019 to 2022,the researches and field tests of CO_(2) pre-fracturing assisted production technology were carried out in Jimsar shale oil block.The application effect of CO_(2) pre-storage fracturing and CO_(2) huff and puff in Jimsar shale oil block was systematically studied and analyzed.The results indicate that supercritical CO_(2) has the effects of miscible energy increase,dissolution to improve reservoir conditions,improve imbibition replacement efficiency,and increase the complexity of fracture network.The optimal injection volume,injection speed,and injection methods were determined,and a preliminary technological system for CO_(2) pre-fracturing in shale oil reservoirs was established.According to the prediction of production data,the CO_(2) prefracturing process can increase the final recovery rate by about 20%,which provides a reference for realizing the benefit development of shale oil and improving the development effect of other types of shale reservoirs.
作者
赵坤
李泽阳
刘娟丽
胡可
江冉冉
王伟祥
刘秀珍
ZHAO Kun;LI Zeyang;LIU Juanli;HU Ke;JIANG Ranran;WANG Weixiang;LIU Xiuzhen(Jiqing Oilfield Area,PetroChina Xinjiang Oilfield Company,Jimsar,Xinjiang 831700,China;Zhundong Oil Production Plant,PetroChina Xinjiang Oilfield Company,Fukang,Xinjiang 831511,China)
出处
《油气藏评价与开发》
CSCD
北大核心
2024年第1期83-90,共8页
Petroleum Reservoir Evaluation and Development
基金
中国石油重大科技专项“陆相页岩油规模增储上产与勘探开发技术研究”(2023ZZ15)。
关键词
CO_(2)前置
储层改造
裂缝扩展规律
参数优化
吉木萨尔页岩油
CO_(2)pre-energizing fracturing
reservoir modification
crack propagation law
parameter optimization
Jimsar shale oil
