针对考虑滤失效应的CO2压裂液在裂缝对流换热过程中关键施工参数对压裂效果影响不明确的问题,通过数值模拟方法研究了液态CO2压裂液在页岩储层中的传热传质过程,以裂缝温度场、压力场和密度场为研究重点,分析了CO2压裂液在页岩裂缝中对流换热的影响因素。研究表明:CO2压裂液注入后,沿裂缝延伸方向,CO2压裂液温度逐步升高,达到峰值后略有下降,最终趋于稳定;CO2压裂液压力逐渐降低,初期下降率较缓,后期急剧下降,最终趋于稳定;CO2压裂液密度逐步减小,达到最低点后略有上升,最终趋于稳定;随注入排量增大,CO2压裂液的最高温度降低,总滤失量增大;随注入温度升高,裂缝中CO2压裂液温度升高,对应位置距裂缝入口处更远,总滤失量更大;随注入压力升高,裂缝中CO2压裂液温度升高,对应位置距裂缝入口处更近,总滤失量减小。该研究结果可为页岩储层CO2压裂设计提供理论借鉴。
To clarify the effects of key operational parameters on fracturing performance during convective heat transfer of CO2 fracturing fluid in fractures(taking into account of filtration loss),numerical simulations were made on the heat and mass transfer of liquid CO2 fracturing fluid in shale reservoir fractures.Focusing on fracture temperature,pressure and density fields,analysis centered on the influencing factors of CO2 convection.The results show that after CO2 injection,along the fracture length,the CO2 fracturing fluid temperature gradually rose to a peak,then slightly decreased before stabilizing;the CO2 pressure decreased gradually with a slow decline initially and a rapid decline later,eventually stabilizing; the CO2 density decreased to a minimum then slightly rises before stabilizing.As the injection rate increases, the maximum temperature of the CO2 fracturing fluid decreases and the total filtration loss increases.Raising the injection temperature increased CO2 temperatures deeper in the fracture(farther from the inlet)and also raised total loss.Increasing the injection pressure raised the CO2 temperature nearer the fracture inlet and reduced total loss.These findings can provide a theoretical reference for designing CO2 fracturing operations in shale reservoirs.
[1] WU Lin,HOU Zhengmeng,LUO Zhifeng,et al.Numerical simulations of supercritical carbon dioxide fracturing:a review[J].Journal of Rock Mechanics and Geotechnical Engineering,2023,15(7):1895-1910.
[2] 郑焰,白小丹,罗于建,等.非常规油气二氧化碳压裂技术研究进展[J].中国石油和化工标准与质量,2019,39(17):221-224,226.
ZHENG Yan,BAI Xiaodan,LUO Yujian,et al.Research progress of CO2 fracturing technology for unconventional oil and gas reservoirs[J].China Petroleum and Chemical Standard and Quality,2019,39(17):221-224,226.
[3] 孙景行, 孙晓冬, 郭东明, 等. 不同渗透率储层超临界CO2改造模拟研究[J]. 工程地质学报, 2024, 32(4): 1334-1346.
SUN Jingxing,SUN Xiaodong,GUO Dongming,et al.Modeling study on the S-CO2 fracturing of reservoirs with different rock matrix permeability[J].Journal of Engineering Geology,2024, 32(4): 1334-1346.
[4] 古发刚,任书泉.多种因素下的滤失速度计算模型[J].西南石油学院学报,1991,13(2):63-71.
GU Fagang,REN Shuquan.Model for calculating fluid-loss velocity under conditions of many factors[J].Journal of Southwest Petroleum Institute,1991,13(2):63-71.
[5] KING S R.Liquid CO2 for the stimulation of low-permeability reservoirs[C].SPE11616-MS,1983:145-148.
[6] MEIER P,IVORY J,DE Rocco M, et al.Field and laboratory measurements of leak off parameters for liquid CO2 and liquid CO2/N2 fracturing[C].PETSOC-97-105,1997:1-6.
[7] SETTARI A,BACHMAN R C,MORRISON D C.Numerical simulation of liquid CO2 hydraulic fracturing[C].PETSOC-86-37-67,1986:399-418.
[8] 孙小辉,孙宝江,王志远.超临界CO2压裂裂缝温度场模型[J].石油学报,2015,36(12):1586-1592.
SUN Xiaohui,SUN Baojiang,WANG Zhiyuan.Fissure temperature field model of supercritical CO2 fracturing[J].Acta Petrolei Sinica,2015,36(12):1586-1592.
[9] 刘真光,邱正松,钟汉毅,等.页岩储层超临界CO2压裂液滤失规律实验研究[J].钻井液与完井液,2016,33(1):113-117.
LIU Zhenguang,QIU Zhengsong,ZHONG Hanyi,et al.Study on filtration property of hypercritical CO2 fracturing fluid for shale reservoirs[J].Drilling Fluid & Completion Fluid,2016,33(1):113-117.
[10] LI Binfei,ZHENG Chao,XU Jianguo,et al.Experimental study on dynamic filtration behavior of liquid CO2 in tight sandstone[J].Fuel,2018,226:10-17.
[11] LI Xiaojiang,LI Gensheng,YU Wei, et al.Thermal effects of liquid/supercritical carbon dioxide arising from fluid expansion in fracturing[J].SPE Journal,2018,23(6):2026-2040.
[12] 郑超.基于相态变化的液态CO2压裂液滤失机制研究[D].青岛:中国石油大学(华东),2021.
ZHENG Chao.Study on filtration mechanism of liquid CO2 fracturing fluid based on phase change[D].Qingdao:China University of Petroleum(East China),2021.
[13] 赵康.页岩储层CO2干法压裂缝内流动传热耦合特性研究[D].大庆:东北石油大学,2024.
ZHAO Kang.Research on coupled characteristics of flow and heat transfer in CO2 dry fracturing of shale reservoirs[D].Daqing:Northeast Petroleum University,2024.
[14] 徐波,王振华,宋婷,等.致密砂岩储层可压裂性的测井评价方法[J].油气地质与采收率,2024,31(6):57-64.
XU Bo,WANG Zhenhua,SONG Ting,et al.Logging evaluation method of fracturability of tight sandstone reservoirs[J].Petroleum Geology and Recovery Efficiency,2024,31(6):57-64.
[15] 蒲春生,康少飞,谷潇雨,等.致密油水平井压裂段剩余油潜力定量研究方法及应用——以鄂尔多斯盆地FX区块为例[J].油气地质与采收率,2023,30(4):147-155.
PU Chunsheng,KANG Shaofei,GU Xiaoyu,et al.Quantitative study method for remaining oil potential in fractured sections of horizontal wells in tight oil reservoirs and itsapplication:a case of Block FX in Ordos Basin[J].Petroleum Geology and Recovery Efficiency,2023,30(4):147-155.
[16] SONG Xianzhi,SHI Yu,LI Gensheng,et al.Numerical simulation of heat extraction performance in enhanced geothermal system with multilateral wells[J].Applied Energy,2018,218:325-337.
[17] 陈欢庆.CO2驱油与埋存技术新进展[J].油气地质与采收率,2023,30(2):18-26.
CHEN Huanqing. New progress of CO2 flooding and storage technology[J].Petroleum Geology and Recovery Efficiency,2023,30(2):18-26.
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