碳酸盐岩裂缝热储回灌水渗流规律影响因素

回灌措施是解决地热水下水位下降，实现地热资源的可持续利用的重要技术措施。然而，目前碳酸盐岩裂缝热储回灌开发中存在回灌水渗流规律不明确，回灌开采模式不清晰、回灌水在碳酸盐岩热储中渗流规律复杂、回灌水如何在裂缝和溶洞中渗流及回灌水的注入方向与裂缝的发育方位之间关系认识不明确等。因此，针对目标碳酸盐岩裂缝热储储层孔隙结构特征，采用微观裂缝刻蚀模型和胶结裂缝平板模型，研究了回灌水的注入速度、注入方向和井网方式对其微观渗流规律影响。回灌微观渗流实验表明：在微观刻蚀模型中，当裂缝方位为90°、注入速度为0.04 mL/min时，回灌水的波及面积最大。提高回灌水的注入速度与增加裂缝方位角度，可以提高碳酸盐岩裂缝热储地层中的回灌水波及面积。在微观刻蚀可视化实验的基础上，利用碳酸盐岩裂缝热储胶结物理模型，研究了回灌水注入的温度场变化情况。温度场显示的波及面积与回灌水的渗流路线与微观刻蚀平板中的基本一致。

Study on the influencing factors law of reinjection water in fractured carbonate fracture thermal storage

The measure of reinjection is an important technical measure to solve the water level drop of geothermal water and realize the sustainable utilization of geothermal resources. However, at present, there are some problems in the reinjection development of carbonate fracture thermal reservoir, such as the law of reinjection seepage is not clear, and the mining mode of reinjection is not clear. The seepage law of reinjection in carbonate fracture thermal reservoir is complex, and the relationship between the seepage of reinjection in fracture and karst cave, the injection direction of reinjection and the development direction of fracture is not clear. Therefore, according to the pore structure characteristics of the target carbonate fracture thermal reservoir, micro fracture etching model and emented fracture plate model are used to study the influence of injection speed, injection direction and well pattern mode of reinjection water on the micro seepage law. In the micro etching model, when the fracture orientation is 90 ° and the injection velocity is 0.04 ml/min, the sweep area of reinjection is the largest. By increasing the injectionrate and the fracture azimuth, the reinjection water wave and area can be increased. Based on the micro etching visualization experiment, the temperature field of reinjection water injection is studied by using the physical model of carbonate fracture thermal reservoir cementation. The sweep area of the temperature field and the seepage route of the backwater are basically the same as those in the micro etching plate.