To address the decline in single-cycle recovery and the slowdown in cumulative recovery increase during the later stage of gas huff-n-puff,CO2,methane,ethane,and propane were selected to carry out extraction experiments using a high-temperature and high-pressure reactor,and gas chromatography was employed to determine the oil components extracted with different gases.Combined with the viscosity changes of the remaining oil after extraction,the molecular mass selectivity of different gases was compared.Moreover, CO2 huff-n-puff and CO2-alternating-alkane huff-n-puff experiments were conducted to evaluate the recovery enhancement effects of different injection methods.The experiments revealed that propane has the highest extraction rate,reaching 62.60% at 30 MPa,ethane andCO2 achieve 53.07% and 49.25% respectively at 30 MPa,and methane has the poorest extraction ability,only 20.47% at 30 MPa.Propane shows the most uniform molecular mass selectivity,extracting all oil components,and ethane preferentially extracts light and medium components,mainly those within C25,while CO2 and methane mainly extract light components within C15.The huff-n-puff experimental results showed that CO2-alternating-alkane huff-n-puff enhances recovery by over 10% compared to CO2-only huff-n-puff,with significant improvements in later-stage recovery per cycle.This research offers valuable insights for enhancing tight oil recovery.
LI Zhihao
,
PI Yanfu
,
LIU Li
,
YANG Jiawen
,
CAI Dongrui
. Experimental study on enhancing tight oil recovery by CO2-alternating-alkane huff-n-puff[J]. Special Oil & Gas Reservoirs, 2025
, 32(3)
: 76
-85
.
DOI: 10.3969/j.issn.1006-6535.2025.03.009
[1] 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.
[2] 金之钧,朱如凯,梁新平,等.当前陆相页岩油勘探开发值得关注的几个问题[J].石油勘探与开发,2021,48(6):1276-1287.
JIN Zhijun,ZHU Rukai,LIANG Xinping,et al.Several issues worthy of attention in current lacustrine shale oil exploration and development[J].Petroleum Exploration and Development,2021,48(6):1276-1287.
[3] 刘美成.致密储层测井评价技术及发展方向[J].特种油气藏,2022,29(4):12-20.
LIU Meicheng.Logging evaluation technology and further development of tight reservoirs[J].Special Oil & Gas Reservoirs,2022,29(4):12-20.
[4] 李斌会,苑盛旺,董大鹏,等.致密砂岩油藏能量补充方式评价及优化[J].特种油气藏,2021,28(6):91-97.
LI Binhui,YUAN Shengwang,DONG Dapeng,et al.Evaluation and optimization of energy supplement methods for tight sandstone reservoirs[J].Special Oil & Gas Reservoirs,2021,28(6):91-97.
[5] 魏兵,刘江,张翔,等.致密油藏提高采收率方法与理论研究进展[J].西南石油大学学报(自然科学版),2021,43(1):91-102.
WEI Bing,LIU Jiang,ZHANG Xiang,et al.Advances of enhanced oil recovery method and theory in tight reservoirs[J].Journal of Southwest Petroleum University(Science & Technology Edition),2021,43(1):91-102.
[6] LI Lei,ZHOU Xiaomei,SU Yuliang,et al.Influence of heterogeneity and fracture conductivity on supercritical CO2 miscible flooding enhancing oil recovery and gas channeling in tight oil reservoirs[J].Energy & Fuels,2022,36(15):8199-8209.
[7] MILAD M,JUNIN R,SIDEK A,et al.Huff-n-puff technology for enhanced oil recovery in shale/tight oil reservoirs:progress,gaps,and perspectives[J].Energy & Fuels,2021,35(21):17279-17333.
[8] 汤翔,李宜强,韩雪,等.致密油二氧化碳吞吐动态特征及影响因素[J].石油勘探与开发,2021,48(4):817-824.
TANG Xiang,LI Yiqiang,HAN Xue,et al.Dynamic characteristics and influencing factors of CO2 huff and puff in tight oil reservoirs[J].Petroleum Exploration and Development,2021,48(4):817-824.
[9] DING Mingchen,WANG Yefei,WANG Wei,et al.Variation of crude oil physical properties and oil recovery of natural gas flood under different pressures[J].Petroleum Science and Technology,2016,34(6):491-498.
[10] SIE C,NGUYEN Q P.Field gas huff-n-puff for improving oil recovery in the eagle ford shale:the effect of injection gas composition and cycle[J].Energy & Fuels,2023,37(7):5154-5164.
[11] PU Wanfen,DU Daijun,Wang Song,et al.Experimental study of CO2 huff-n-puff in a tight conglomerate reservoir using true triaxial stress cell core fracturing and displacement system:a case study[J].Journal of Petroleum Science and Engineering,2021,199(1):1-10.
[12] 师调调,杜燕,党海龙,等.志丹油区长7页岩油储层CO2吞吐室内实验[J].特种油气藏,2023,30(6):128-134.
SHI Tiaotiao,DU Yan,DANG Hailong,et al.Indoor experiment on CO2 huff-n-puff in Chang 7 shale oil reservoir in Zhidan oil region[J].Special Oil & Gas Reservoirs,2023,30(6):128-134.
[13] 马清杰,闫娥,蒲万芬,等.塔河托甫台区块注天然气与CO2提高采收率实验研究[J].科学技术与工程,2017,17(8):14-20.
MA Qingjie,YAN E,PU Wanfen,et al.Experimental study on the natural gas and CO2 injection EOR processes in Tuofutai Block of Tahe Oilfield[J].Science Technology and Engineering,2017,17(8):14-20.
[14] DING M,WANG Y,LIU D,et al.Mutual interactions of CO2/oil and natural gas/oil systems and their effects on the EOR process[J].Petroleum Science and Technology,2015,33(23/24):1890-1900.
[15] 高颖,戴连奎,朱华东,等.基于拉曼光谱的天然气主要组分定量分析[J].分析化学,2019,47(1):67-76.
GAO Ying,DAI Liankui,ZHU Huadong,et al.Quantitative analysis of main components of natural gas based on raman spectroscopy[J].Chinese Journal of Analytical Chemistry,2019,47(1):67-76.
