两相流与溶液化学平衡相结合的地热井结垢模拟研究

Geothermal Well Scaling Simulation by Combining Two Phase Flow with Chemical Equilibrium

水热型地热系统和干热岩增强型地热系统在运行一段时间后都有可能出现井筒和管道设备结垢现象,困扰和阻碍着地热资源的高效低成本开发。由于温度和压力变化导致CO_(2)从地热水中逸出,进而使得CaCO_(3)析出结垢,是地热生产井堵塞的主要原因。将两相流动换热计算与水溶液物理化学模拟相结合,针对地热井内CaCO_(3)垢进行流动换热与化学组分变化的模拟和计算方法的研究,获得了特定地热条件下井筒内流动状况与化学组分变化情况的详细分析结果,可为井筒地热水流动进行结垢分析和预测。

Both hydrothermal geothermal system and hot dry rock enhancement geothermal system may experience scaling problem in the wells or facility on the ground after an operation period.Scaling problems inhibit the efficient exploitation of geothermal resources.For carbonate scale in production wells,the temperature and pressure changes in the fluid cause the release of CO2 from the geothermal solution,and lead to supersaturation of the solubility of carbonate calcium.In this paper,two-phase flow model and chemical reaction simulation were integrated together to simulate the scaling problems in production wells to reveal detail temperature and pressure of the flow states and the changes of chemical components simultaneously.The model can be used to be a scaling prediction and analytical tool for geothermal production wells.