Huff-n-puff experiments of mixed CO₂ and formation water for enhanced oil recovery of shale oil in the Subei Basin

Authors

XIAO Pufu, State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Efficient Development, Beijing 102206, China; Petroleum Exploration and Production Research Institute, SINOPEC, Beijing 102206, ChinaFollow
ZHANG Jie, State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Efficient Development, Beijing 102206, China; Petroleum Exploration and Production Research Institute, SINOPEC, Beijing 102206, China
YANG Zhengmao, East China Oil & Gas Company, SINOPEC, Nanjing 210019, China
WANG Rui, State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Efficient Development, Beijing 102206, China; Petroleum Exploration and Production Research Institute, SINOPEC, Beijing 102206, China
CUI Maolei, State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Efficient Development, Beijing 102206, China; Petroleum Exploration and Production Research Institute, SINOPEC, Beijing 102206, China
LEI Mengmeng, School of Chemistry and Chemical Engineering, Henan University of Technology, Zhengzhou 450001, China
TIAN Yunfei, State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Efficient Development, Beijing 102206, China; Petroleum Exploration and Production Research Institute, SINOPEC, Beijing 102206, ChinaFollow
ZENG Jun, East China Oil & Gas Company, SINOPEC, Nanjing 210019, China
LIU Yuwei, State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Efficient Development, Beijing 102206, China; Petroleum Exploration and Production Research Institute, SINOPEC, Beijing 102206, China

Abstract

Objective In the Subei Basin, the depletion-drive development of shale oil following reservoir volume fracturing faces challenges such as rapid production decline and low oil recovery. To address these issues, this study explored an experimental method of CO₂ + formation water (also referred to as carbonated water) huff and puff for enhanced oil recovery (EOR) by combining the felsic, clayey, and organic-rich characteristics of shale oil reservoirs in the Subei Basin, along with CO₂ high pressure quality exchange technology. Methods Through multiple physical simulation experiments in the laboratory, combined with nuclear magnetic resonance (NMR) experiment technology, this study conducted dynamic and static experiments on cores, including high-temperature and high-pressure imbibition, dissolution, and carbonated water huff and puff, to verify the feasibility of carbonated water huff and puff for shale oil recovery. Variations in 2D NMR T₁-T₂ spectra were analyzed to determine the characteristics and patterns of the production of different types of crude oil during huff and puff. Results and Conclusions By creating acidic conditions, CO₂ huff and puff following imbibition could dissolve minerals such as calcites and dolomites in shale oil reservoirs, thus improving the microscopic pore-throat structures in the reservoirs, as well as the porosity and permeability of cores. Accordingly, the late-stage shale oil recovery was enhanced. Comparison of CO₂ and carbonated water huff and puff revealed that the carbonated water huff and puff increased the injection-production pressure difference, enhancing cumulative recovery by 6.7%. In the first several rounds, CO₂ huff and puff achieved rapid and effective production of movable oil and light hydrocarbons, enhancing oil recovery more significantly. In contrast, in the late stage, the carbonated water huff and puff expanded the influence of CO₂ through dissolution and diffused CO₂ into more matrix pores. Consequently, the conversion between heavy hydrocarbons (or adsorbed oil) and light hydrocarbons was gradually achieved through mass transfer, resulting in significantly improved huff-n-puff performance. Therefore, to achieve the optimal shale oil recovery, it is advisable to adopt two rounds of CO₂ huff and puff in the early stage, followed by multiple rounds of carbonated water huff and puff in the late stage, when designing huff-n-puff schemes in the field. Overall, the results of this study reveal the mechanisms by which the carbonated water huff and puff enhance crude oil production, confirming the feasibility of this method for EOR of shale oil. This study provides a significant experimental basis and new directions for developing EOR technologies for shale oil reservoirs in the Subei Basin and even in eastern China.

Keywords

Subei Basin, shale oil, CO2, huff and puff, nuclear magnetic resonance, enhanced oil recovery (EOR)

DOI

10.12363/issn.1001-1986.25.07.0558

Recommended Citation

XIAO Pufu, ZHANG Jie, YANG Zhengmao, et al. (2026) "Huff-n-puff experiments of mixed CO₂ and formation water for enhanced oil recovery of shale oil in the Subei Basin," Coal Geology & Exploration: Vol. 54: Iss. 1, Article 14.
DOI: 10.12363/issn.1001-1986.25.07.0558
Available at: https://cge.researchcommons.org/journal/vol54/iss1/14

Reference

[1] 李阳,祝仰文,李宗阳,等. 济阳坳陷页岩油注二氧化碳开发技术[J]. 石油勘探与开发,2024,51(4):855−864

LI Yang,ZHU Yangwen,LI Zongyang,et al. Shale oil recovery by CO₂ injection in Jiyang Depression,Bohai Bay Basin,East China[J]. Petroleum Exploration and Development,2024,51(4):855−864

[2] 段毅,张胜斌,郑朝阳,等. 鄂尔多斯盆地马岭油田延安组原油成因研究[J]. 地质学报,2007,81(10):1407−1415

DUAN Yi,ZHANG Shengbin,ZHENG Zhaoyang,et al. Study on genesis of crude oil in the Yan’an Formation of the Maling Oilfield,Ordos Basin[J]. Acta Geologica Sinica,2007,81(10):1407−1415

[3] LI Guoxin,XIAN Chenggang,LIU He. A “one engine with six gears” system engineering methodology for the economic development of unconventional oil and gas in China[J]. Engineering,2022,18:105−115.

[4] 贾承造,王祖纲,姜林,等. 中国页岩油勘探开发研究进展与科学技术问题[J]. 世界石油工业,2024,31(4):1−11

JIA Chengzao,WANG Zugang,JIANG Lin,et al. Progress and key scientific and technological problems of shale oil exploration and development in China[J]. World Petroleum Industry,2024,31(4):1−11

[5] 姚红生,高玉巧,郑永旺,等. CO₂快速吞吐提高页岩油采收率现场试验[J]. 天然气工业,2024,44(3):10−19

YAO Hongsheng,GAO Yuqiao,ZHENG Yongwang,et al. Field tests and effect of CO₂ rapid huff–n–puff to enhance shale oil recovery[J]. Natural Gas Industry,2024,44(3):10−19

[6] HOFFMAN B T. Comparison of various gases for enhanced recovery from shale oil reservoirs[C]//SPE Improved Oil Recovery Symposium. Tulsa：Society of Petroleum Engineers，2012：SPE–154329–MS.

[7] GAMADI T D，SHENG J J，SOLIMAN M Y，et al. An experimental study of cyclic CO₂ injection to improve shale oil recovery[C]//SPE Improved Oil Recovery Symposium. Tulsa：Society of Petroleum Engineers，2014：SPE–169142–MS.

[8] GAMADI T D，SHENG J J，SOLIMAN M Y. An experimental study of cyclic gas injection to improve shale oil recovery[C]//SPE Annual Technical Conference and Exhibition. New Orleans：Society of Petroleum Engineers，2013：SPE–166334–MS.

[9] 赵文智,胡素云,侯连华,等. 中国陆相页岩油类型、资源潜力及与致密油的边界[J]. 石油勘探与开发,2020,47(1):1−10

ZHAO Wenzhi,HU Suyun,HOU Lianhua,et al. Types and resource potential of continental shale oil in China and its boundary with tight oil[J]. Petroleum Exploration and Development,2020,47(1):1−10

[10] 刘博峰,张庆九,陈鑫,等. 致密油储层压裂液渗吸特征及水锁损害评价[J]. 断块油气田,2021,28(3):318−322

LIU Bofeng,ZHANG Qingjiu,CHEN Xin,et al. Imbibition characteristics of fracturing fluid in the tight oil reservoir and water lock damage evaluation[J]. Fault–Block Oil & Gas Field,2021,28(3):318−322

[11] ALHARTHY N，TEKLU T W，KAZEMI H，et al. Enhanced oil recovery in liquid–rich shale reservoirs：Laboratory to field[C]//SPE Annual Technical Conference and Exhibition. Houston：Society of Petroleum Engineers，2015：SPE–175034–MS.

[12] 曹长霄,宋兆杰,师耀利,等. 吉木萨尔页岩油二氧化碳吞吐提高采收率技术研究[J]. 特种油气藏,2023,30(3):106−114

CAO Changxiao,SONG Zhaojie,SHI Yaoli,et al. Study on CO₂ huff–n–puff enhanced recovery technology for Jimsar shale oil[J]. Special Oil & Gas Reservoirs,2023,30(3):106−114

[13] 袁士义,雷征东,李军诗,等. 陆相页岩油开发技术进展及规模效益开发对策思考[J]. 中国石油大学学报(自然科学版),2023,47(5):13−24

YUAN Shiyi,LEI Zhengdong,LI Junshi,et al. Progress in technology for the development of continental shale oil and thoughts on the development of scale benefits and strategies[J]. Journal of China University of Petroleum (Edition of Natural Science),2023,47(5):13−24

[14] 张志超,李红雷,于春勇,等. CO₂开发页岩油藏研究进展[J]. 油田化学,2023,40(3):543−549

ZHANG Zhichao,LI Honglei,YU Chunyong,et al. Research progress of shale reservoir development with CO₂[J]. Oilfield Chemistry,2023,40(3):543−549

[15] WAN Tao,MU Zongjie. The use of numerical simulation to investigate the enhanced Eagle Ford shale gas condensate well recovery using cyclic CO₂ injection method with nano–pore effect[J]. Fuel,2018,233:123−132.

[16] 宋兆杰,邓森,宋宜磊,等. 大庆油田古龙页岩油–CO₂高压相态及传质规律[J]. 石油学报,2024,45(2):390−402

SONG Zhaojie,DENG Sen,SONG Yilei,et al. High–pressure phase behavior and mass transfer law of Gulong shale oil and CO₂ in Daqing Oilfield[J]. Acta Petrolei Sinica,2024,45(2):390−402

[17] 宋宜磊. 纳米限域效应作用下古龙页岩油注CO₂相变与流动机制研究[D]. 北京：中国石油大学(北京)，2023.

SONG Yilei. Phase behavior and fluid flow of CO₂ injection in Gulong shale oil under the nano–confinement effect[D]. Beijing：China University of Petroleum (Beijing)，2023.

[18] WANG Lu,ZHANG Yifan,ZOU Rui,et al. A systematic review of CO₂ injection for enhanced oil recovery and carbon storage in shale reservoirs[J]. International Journal of Hydrogen Energy,2023,48(95):37134−37165.

[19] 李凤霞,王海波,周彤,等. 页岩油储层裂缝对CO₂吞吐效果的影响及孔隙动用特征[J]. 石油钻探技术,2022,50(2):38−44

LI Fengxia,WANG Haibo,ZHOU Tong,et al. The influence of fractures in shale oil reservoirs on CO₂ huff and puff and its pore production characteristics[J]. Petroleum Drilling Techniques,2022,50(2):38−44

[20] 刘佳慧，苏玉亮，李蕾，等. 基于微流控实验的页岩油CO₂吞吐提高采收率微观机理研究[C]//2022油气田勘探与开发国际会议论文集Ⅳ. 西安，2022：IFEDC–202211893.

[21] CHAIBOU IBRAHIM M A. 页岩油藏注CO₂吞吐提高采收率评价研究[D]. 东营：中国石油大学(华东)，2019.

CHAIBOU IBRAHIM M A. Evaluation on EOR performance of gas huff–n–puff in shale oil reservoirs[D]. Dongying：China University of Petroleum (East China)，2019.

[22] 李斌会,邓森,张江,等. 古龙页岩油高温高压注CO₂驱动用效果[J]. 大庆石油地质与开发,2024,43(1):42−51

LI Binhui,DENG Sen,ZHANG Jiang,et al. Producing effect of CO₂ displacement injection at high temperature and high pressure for Gulong shale oil[J]. Petroleum Geology & Oilfield Development in Daqing,2024,43(1):42−51

[23] 刘客,张驰. 裂缝作用下CO₂吞吐动用基质页岩油特征[J]. 大庆石油地质与开发,2024,43(2):152−159

LIU Ke,ZHANG Chi. Characteristics of CO₂ huff–and–puff producing matrix shale oil effected by fractures[J]. Petroleum Geology & Oilfield Development in Daqing,2024,43(2):152−159

[24] 李邦国,侯家鵾,雷兆丰,等. 超临界CO₂萃取页岩油效果评价及影响因素分析[J]. 石油钻探技术,2024,52(4):94−103

LI Bangguo,HOU Jiakun,LEI Zhaofeng,et al. Evaluation of shale oil extraction by supercritical CO₂ and analysis of influencing factors[J]. Petroleum Drilling Techniques,2024,52(4):94−103

[25] 窦卓颖,杨正明,张亚蒲,等. 页岩油不同注气介质吞吐技术研究进展[J]. 天然气与石油,2023,41(6):73−81

DOU Zhuoying,YANG Zhengming,ZHANG Yapu,et al. Research progress on huff and puff technology of different injection gases in shale oil reservoirs[J]. Natural Gas and Oil,2023,41(6):73−81

[26] 唐维宇,黄子怡,陈超,等. 吉木萨尔页岩油CO₂吞吐方案优化及试验效果评价[J]. 特种油气藏,2022,29(3):131−137

TANG Weiyu,HUANG Ziyi,CHEN Chao,et al. Optimization of CO₂ huff and puff scheme for Jimsar shale oil and evaluation of test effect[J]. Special Oil & Gas Reservoirs,2022,29(3):131−137

[27] 曲方春,刘东旭,王青振,等. 古龙页岩油注CO₂补能提高采收率机理及参数优化[J]. 大庆石油地质与开发,2025,44(1):107−113

QU Fangchun,LIU Dongxu,WANG Qingzhen,et al. Mechanism and parameters optimization of CO₂ injection for energy complement to enhance recovery of Gulong shale oil[J]. Petroleum Geology & Oilfield Development in Daqing,2025,44(1):107−113

[28] 昝灵,白鸾羲,印燕铃,等. 苏北盆地溱潼凹陷古近系阜宁组二段页岩油基本特征及成因分析[J]. 石油实验地质,2023,45(2):356−365

ZAN Ling,BAI Luanxi,YIN Yanling,et al. Basic characteristics and genesis analysis of shale oil in the second member of Paleogene Funing Formation in Qintong Sag,Subei Basin[J]. Petroleum Geology & Experiment,2023,45(2):356−365

[29] 姚红生,云露,昝灵,等. 苏北盆地溱潼凹陷阜二段断块型页岩油定向井开发模式及实践[J]. 油气藏评价与开发,2023,13(2):141−151

YAO Hongsheng,YUN Lu,ZAN Ling,et al. Development mode and practice of fault–block oriented shale oil well in the second member of Funing Formation,Qintong Sag,Subei Basin[J]. Petroleum Reservoir Evaluation and Development,2023,13(2):141−151

[30] 杨明,薛程伟,李朝阳,等. 页岩油CO₂吞吐影响因素及微观孔隙动用特征[J]. 大庆石油地质与开发,2023,42(4):148−156

YANG Ming,XUE Chengwei,LI Chaoyang,et al. Influencing factors of CO₂ huff and puff and micro–pores producing characteristics of shale oil[J]. Petroleum Geology & Oilfield Development in Daqing,2023,42(4):148−156

[31] 张洪权. 页岩油注二氧化碳吞吐作用机制及传质规律研究[D]. 北京：中国石油大学(北京)，2022.

ZHANG Hongquan. Study on action mechanism and mass transfer law between shale oil and injected carbon dioxide huff–n–puff[D]. Beijing：China University of Petroleum (Beijing)，2022.

[32] ALAVIAN S A. Modeling CO₂ injection in fractured reservoirs using single matrix block systems[D]. Trondheim：Norwegian University of Science and Technology，2011.

[33] 周晓梅,李蕾,苏玉亮,等. 超临界CO₂/H₂O混合流体吞吐提高页岩油采收率实验研究[J]. 油气地质与采收率,2023,30(2):77−85

ZHOU Xiaomei,LI Lei,SU Yuliang,et al. Experimental study on enhancing shale oil recovery by supercritical CO₂/H₂O mixture huff and puff[J]. Petroleum Geology and Recovery Efficiency,2023,30(2):77−85

[34] 张金风,梁成钢,陈依伟,等. 表面活性剂对页岩油储层高温高压渗吸驱油效果的影响因素[J]. 大庆石油地质与开发,2023,42(3):167−174

ZHANG Jinfeng,LIANG Chenggang,CHEN Yiwei,et al. Influence factors of surfactant on high–temperature and high–pressure imbibition displacement effect of shale oil reservoir[J]. Petroleum Geology & Oilfield Development in Daqing,2023,42(3):167−174

[35] 丁帅伟，张蒙，李远铎，等. 致密油藏CO₂吞吐驱油和封存注采参数敏感性分析——以鄂尔多斯盆地延长组长7段致密油藏典型储集层为例 [J]. 新疆石油地质，2024，45 (2)：181−188.

DING Shuaiwei，ZHANG Meng，LI Yuanduo，et al. Sensitivity analysis of injection-production parameters for CO₂ huff-n-puff flooding and storage in tight oil reservoirs：A case from typical tight reservoirs of Chang 7 member，Ordos basin [J].Xinjiang Petroleum Geology，2024，45 (2)：181−188.

[36] 闫健,佀彬凡,孙晓东,等. 页岩油储层超临界CO₂吞吐用气溶性表面活性剂性能评价[J]. 断块油气田,2023,30(4):566−571

YAN Jian,SI Binfan,SUN Xiaodong,et al. Performance evaluation of gas soluble surfactants for supercritical CO₂ huff and puff in shale oil reservoirs[J]. Fault–Block Oil & Gas Field,2023,30(4):566−571

[37] 卢子建,钟陵,段晓苗,等. 二甲醚辅助CO₂驱提高页岩油采收率可行性实验:以四川盆地长宁地区奥陶系五峰组为例[J]. 大庆石油地质与开发,2024,43(1):77−85

LU Zijian,ZHONG Ling,DUAN Xiaomiao,et al. Feasibility experiment on improving shale oil recovery by DME–assisted CO₂ flooding:Taking Ordovician Wufeng Formation in Changning area in Sichuan Basin as an example[J]. Petroleum Geology & Oilfield Development in Daqing,2024,43(1):77−85