Investigation of hydraulic throttling within geothermal injection well filter using CFD simulation

Abstract

The study presented in this paper is dedicated to determining parameters that sufficiently represent fluid flow throttling of a geothermal system injection well filter affected by sediment formation. The aforementioned parameters are to be used in a custom mathematical model that includes all significant elements of a geothermal system necessary to conduct hydrodynamic studies on a macroscopic scale. The calculations were done using computational Fluid Dynamics (CFD) CFD software supplied with 3D geometry of a filter segment, consisting of a cylindrical hole obstructed by several rows of trapezoid wire, providing narrow gaps through which the geothermal fluid exits the injection well pipeline. Fluid flow was computed for 100 cases of varied inlet and outlet pressure difference and filter geometry based on proposed sediment formation model. The calculated multiple case fluid flow values were used to determine the throttling parameter array of the geothermal well filter based on fluid flow equation that is to be used in a custom model. The resulting data array covers all filter gap and pressure difference values needed for a related study with a custom model, making it possible to accurately represent small-scale processes when modelling a relatively large system.