准噶尔盆地吉木萨尔凹陷页岩油藏注CO2吞吐提高采收率机理
Mechanism of CO2 EOR in shale oil reservoirs in the Jimsar Sag,the Junggar Basin
左名圣 1陈浩 1赵杰文 2刘希良 1孟展 3柏明星 4杨江 4武艺 5刘海鹏 5齐新雨 5程威铭5
作者信息
- 1. 中国石油大学(北京)安全与海洋工程学院;油气资源与工程全国重点实验室·中国石油大学(北京)
- 2. 中国石油集团测井公司新疆分公司
- 3. 西南石油大学石油与天然气工程学院
- 4. 东北石油大学石油工程学院
- 5. 中国石油大学(北京)安全与海洋工程学院
- 折叠
摘要
页岩油藏的成功开发在缓解我国能源紧缺的问题上发挥了重要作用,但衰竭式开发采收率较低,传统提高采收率的措施难以有效增产,因此明确页岩油藏注CO2 提高采收率的机理,对于探索页岩油的开发技术具有重要意义.为此,以准噶尔盆地吉木萨尔凹陷页岩油藏为例,开展了一系列注CO2 实验并结合流体注入能力和油气组分传质评价实验,揭示了注CO2 吞吐提高采收率的机理,并明确了注CO2 吞吐的埋存形式、埋存效率与其生产动态之间的耦合关系.研究结果表明:①CO2 的注入能力是水的 7.77 倍、N2的 1.18 倍;增加注入压力,促进CO2 与原油之间的相互作用,能有效提高CO2 的注入能力.②CO2 对原油物性的改善能力显著强于N2,在CO2—原油组分传质的协同作用下,注CO2 吞吐的采收率比N2 高 6.84%.③原油膨胀和黏度降低是注CO2 吞吐前期提高采收率的主要机制,而后期主要通过CO2 对原油轻质烃类组分置换、萃取进一步实现了采收率的提高,混相压力(MMP)是注CO2吞吐的阈值压力.④注CO2 吞吐过程中,埋存率从最初的 77.77%持续降低到 7.14%,不同形式CO2 的埋存比例具有动态变化的特征,但主要以游离态和溶解态埋存为主.结论认为,吉木萨尔凹陷页岩油藏注CO2 吞吐在提高采收率的同时实现了CO2 的埋存,实验结果为研究国内相似页岩油藏注CO2 吞吐提采—埋存效率提供理论支撑和经验借鉴.
Abstract
The successful development of shale oil reservoirs plays an important role in alleviating the energy shortage in China,but the depletion development can only realize lower recovery factor,and the conventional enhanced oil recovery(EOR)measures can hardly provide effective production and efficiency improvement,so clarifying the mechanisms of CO2 EOR in shale oil reservoirs is of great significance to exploring the shale oil development technologies.Focusing on the shale oil reservoirs in the Jimsar Sag of the Junggar Basin,this paper carries out a series of CO2 injection experiments.Then,combined with the assessment experiments of fluid injection capacity and oil-CO2 component mass transfer,the mechanisms of CO2 EOR are revealed,and the coupling relationships between the efficiency and form of CO2 sequestration and the production performance are illustrated.And the following research results are obtained.First,the injection capacity of CO2 is 7.77 times that of water and 1.18 times that of N2.Increasing injection pressure facilitates interactions between CO2 and oil,effectively enhancing CO2 injection capacity.Second,the ability of CO2 to improve the physical properties of oil is significantly stronger than that of N2.Under the synergistic effect of CO2-oil component mass transfer,the recovery factor by CO2 EOR is 6.84%higher than that by N2 EOR.Third,oil expansion and viscosity reduction are the main EOR mechanisms in the early stage of CO2 flooding.In the later stage,the further increase of recovery factor is realized through the replacement and extraction of light hydrocarbon components from oil by CO2.Miscible pressure(MMP)is the threshold pressure of CO2.Fourth,in the process of CO2 injection,the sequestration rate decreases continuously from the initial 77.77%to 7.14%.The proportions of different forms of CO2 sequestration change dynamically,but mainly in the form of free state and dissolved state.In conclusion,CO2 injection in the shale oil reservoir of the Jimsar Sag not only enhances the recovery factor but also facilitates CO2 sequestration.The experimental results provide theoretical support and experience insight for CO2 EOR and sequestration efficiency improvement of similar shale oil reservoirs in China.
关键词
准噶尔盆地/吉木萨尔凹陷/页岩油/提高采收率/注CO2/吞吐/CO2/埋存/注入能力/CCUSKey words
Junggar Basin/Jimsar Sag/Shale oil/Enhanced oil recovery(EOR)/CO2 huff and puff/CO2 sequestration/Injection capacity/CCUS引用本文复制引用
基金项目
国家自然科学基金面上项目(52274053)
北京市自然科学基金面上项目(3232028)
出版年
2024
国家科技期刊平台
NSTL
万方数据