CO_2压裂参数对井内温度和压力的影响  

Effect of CO2Fracturing Parameters on Well Temperature and Pressure

作　　者：兰建平 龚群[3] 徐治国 Lan Jianping;Gong Qun;Xu Zhiguo(Changqing Downhole Service Company,CNPC Chuanqing Drilling Engineering Company Limited;CO2 Fracturing Stimulation Laboratory of Key Laboratory of Reservoir Stimulation,CNPC;Institute of Engineering Thermophysics,Shanghai Jiaotong University)

机构地区：[1]川庆钻探工程有限公司长庆井下技术作业公司 [2]中国石油天然气集团公司油气藏改造重点实验室二氧化碳压裂增产研究室 [3]上海交通大学工程热物理研究所

出　　处：《石油机械》2018年第11期97-103,共7页China Petroleum Machinery

基　　金：上海交通大学和川庆长庆井下合作项目"CO2压裂改造过程中管道温度;压力分布理论模型建立技术服务"(cqzt-cqjx-2017-zcj-016)

摘　　要：由于超临界CO_2液体的热物理性质在流动中变化剧烈,不适用于常物性的计算方法,提出了井筒内耦合流体热物性的非稳态流动传热模型。以一个气田为实例,通过数值求解3大控制方程,获得了CO_2的温度和压力沿井深的分布及随施工时间的变化规律。数值模拟结果表明:在计算条件下随着井深增加,井筒内CO_2温度和压力均升高;摩擦阻力对井筒内温度场有显著的影响;随着低温CO_2的注入,井筒内各点温度降低而压力上升,最后都趋于稳定;距离地面越近,井筒内的温度和压力越快达到稳定。得到的井底温度和压力变化规律可以为地层裂缝的计算提供更准确的入口参数。Since the thermo physical properties of supercritical CO 2 change drastically in the flow,the calculation method of common physical properties is not suitable.Therefore,an unsteady flow heat transfer model of coupled fluid thermal properties in the wellbore is proposed.Taking a gas field for case study,the distribution of CO 2 temperature and pressure along the well depth and their variation with construction time are obtained by numerically solving three control equations.The numerical simulation results show that the CO 2 temperature and pressure in the wellbore increase with the increase of well depth under the calculation conditions.The frictional resistance has a significant effect on the temperature field in the wellbore.With the injection of low temperature CO 2,the temperature in the wellbore decreases and the pressure increases,and finally tend to be stable.The closer to the ground,the faster the temperature and pressure in the wellbore reaches stable state.The resulting bottomhole temperature and pressure could provide more accurate input parameters for the calculation of formation fractures.

关 键 词：CO2 压裂 摩擦阻力 温度 压力 

分 类 号：TE28[石油与天然气工程—油气井工程]