碳酸盐岩酸蚀裂缝渗流-传热特性

Seepage and Heat Transfer Characteristics of Acid Corroded Fractures in Carbonate Rock

充分认识流体在碳酸盐岩酸蚀裂隙面上的渗流传热特性,实现地热能的可持续开发利用是十分必要的。针对碳酸盐岩热储非均质性和缝洞发育的突出特点,采用自主研发的实时高温常规三轴试验系统,真实模拟岩石裂隙的真实对流换热过程。采用COMSOL Multiphysics软件对碳酸盐岩单裂隙渗流传热过程进行了模拟计算,开展了实际热储层环境条件下对流换热仿真分析,研究了碳酸盐岩裂缝渗流传热耦合机理。结果表明,裂缝表面进行非均匀性溶蚀,形成一条具有导流能力的人工裂缝,达到改善流体渗流条件的目的;在温度一定的条件下,对流换热系数增幅与流量、压强呈正相关。实验结果验证了数值模拟的正确性与可靠性,获得了储层温度场的演化规律。

It was necessary to fully understand the seepage and heat transfer characteristics of fluid on carbonate rock etched fracture surface and realize the sustainable development and utilization of geothermal energy.A self-developed real-time high-temperature conventional triaxial test system can truly simulate the real convective heat transfer process of rock fractures according to the outstanding characteristics of heterogeneity and fracture-cavity development of carbonate thermal reservoir.COMSOL Multiphysics software was used to simulate the seepage heat transfer process of carbonate rock single fracture,and the convection heat transfer simulation analysis under the actual thermal reservoir environment was carried out.The coupling mechanism of seepage and heat transfer in carbonate fractures was studied by means of experiment and simulation.The results show that an artificial fracture with conductivity is formed by non-uniform dissolution on the fracture surface,so as to improve the fluid seepage conditions.Under the condition of certain temperature,the increase of convective heat transfer coefficient is positively correlated with flow rate and pressure.The experimental results verify the correctness and reliability of the numerical simulation,and obtain the evolution law of reservoir temperature field.