自支撑相变压裂技术中相变热对裂缝温度的影响  

Effects of phase-transition heat on fracture temperature in self-propping phase-transition fracturing technology

作　　者：张楠林 刘福深 姜亮亮[3] 罗志锋[2] 琚宜文 刘平礼[2] 赵立强[2] 裴宇昕 ZHANG Nanlin;LIU Fushen;JIANG Liangliang;LUO Zhifeng;JU Yiwen;LIU Pingli;ZHAO Liqiang;PEI Yuxin(Research Center of Coastal and Urban Geotechnical Engineering,Zhejiang University,Hangzhou 310058,China;National Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Southwest Petroleum University,Chengdu 610500,China;Department of Chemical and Petroleum Engineering,University of Calgary,Calgary T2N1N4,Canada;Key Laboratory of Computational Geodynamics,College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049,China;School of Petroleum and Natural Gas Engineering,Changzhou University,Changzhou 213164,China)

机构地区：[1]浙江大学滨海和城市岩土工程研究中心,杭州310058 [2]西南石油大学油气藏地质及开发工程全国重点实验室,成都610500 [3]卡尔加里大学化学与石油工程系,卡尔加里T2N1N4 [4]中国科学院大学地球与行星科学学院计算地球动力学重点实验室,北京100049 [5]常州大学石油与天然气工程学院,江苏常州213164

出　　处：《石油勘探与开发》2024年第6期1374-1383,共10页Petroleum Exploration and Development

基　　金：中国博士后科学基金“CO_(2)封存库盖层的化学-温度-应力损伤与变形破坏机制研究”(2024M752803);自然资源部深部地热资源重点实验室开放基金“深层地热储层的力学-化学损伤与变形破坏机制研究”(KLDGR2024B01);国家自然科学基金“非饱和裂隙介质水力压裂机理与内嵌不连续有限元模拟”(52179112);油气藏地质及开发工程国家重点实验室开放基金“CO_(2)力学-化学作用下砂岩储层变形破坏机制研究”(PLN2023-02)。

摘　　要：采用差示扫描量热法测试了相变流体热通量曲线,以此建立反映相变转化率与温度、时间关系的反应动力学模型,进而构建了考虑相变热的裂缝和岩体温度场模型,采用前人建立的温度场模型验证了本模型的可靠性,利用新模型研究了不同注入参数、相变压裂液性能参数对裂缝和岩体温度变化的影响规律。研究表明:缝内温度在不同位置、不同时间受注入冷流体的冷却效应和相变过程中的放热效应交替主导;压裂液注入初期,缝内温度较高、相变速度较快,相变放热对储层岩石温度影响较大;注入后期,缝内温度降低,相变放热速度减慢、压裂液对储层岩石的冷却效应增强。相变热对裂缝温度的影响较大,与不考虑相变热相比,当考虑相变热时,注液结束时缝内温度均有不同程度上升,当相变热由20J/g上升至60J/g时,缝内温度上升最大值由2.1℃升至6.2℃。相变热和相变流体(PF)体积分数与裂缝温度变化呈正相关,比热容则与温度变化呈负相关。随着注入时间的增加,缝口温度、相变速度逐渐降低,最大相变速度和最大温度差值位置逐渐从缝口转移到距缝口约10 m处。The thermal flux curve of phase-transition fluid(PF)was tested using differential scanning calorimetry,based on which a reaction kinetics model was established to reflect the relationship between phase transition conversion rate,temperature and time.A temperature field model for fractures and rock matrix considering phase transition heat was then constructed,and its reliability was verified using previously established temperature field models.Additionally,the new model was used to study the effects of different injection parameters and phase-transition fracturing performance parameters on the temperature variations in fractures and matrix.The study indicates that,at different positions and times,the cooling effect of the injected cold fluid and the exothermic effect during the phase transition alternately dominate the temperature within the fracture.At the initial stage of fracturing fluid injection,the temperature within the fracture is high,and the phase transition rate is rapid,resulting in a significant impact of exothermic phase transition on the reservoir rock temperature.In the later stage of injection,the fracture temperature decreases,the phase transition exothermic rate slows,and the cooling effect of the fracturing fluid on the reservoir rock intensifies.Phase transition heat significantly affects the temperature of the fracture.Compared to cases where phase transition heat is not considered,when it is taken into account,the temperature within the fracture increases to varying degrees at the end of fluid injection.As the phase transition heat increases from 20 J/g to 60 J/g,the maximum temperature rise in the fracture increases from 2.1℃to 6.2℃.The phase transition heat and PF volume fraction are positively correlated with fracture temperature changes,while specific heat capacity is negatively correlated with temperature changes.With increasing injection time,the temperature and phase transition rate at the fracture opening gradually decrease,and the location of the maximum phase transition rate a

关 键 词：自支撑相变压裂 原位自生支撑剂 反应动力学 相变热 相变速度 裂缝温度 

分 类 号：TE355[石油与天然气工程—油气田开发工程]