Calculation of fracture water pressure and contribution rate of geothermal water recharge-discharge under the action of Earth Tides

Quantitative identification of the main controlling structures of groundwater and calculation of the contribution rates of different structural fractures are important contents in the study of geothermal water circulation. It has important application value for guiding geothermal resources exploration, extraction, and recharge. This article monitors the pressure changes of deep pressurized geothermal water wells, based on the mechanism of solid tide groundwater response, extracts the pressure values of fracture water, analyzes the relationship between fracture water pressure and solid tide volume strain, establishes a mathematical model of strain and contribution rate of different structural fracture strains under the action of solid tide, and applies it to the research practice of Xiaobu geothermal water. The research shows that the fracture water pressure is monotonically linearly positively correlated with the volume strain, with a correlation coefficient of 0.9151 and an R² value of 0.8374; F1 contributes the most to the discharge of geothermal water (26.26%) and the more to the recharge (20.18%); F5 contributes the most to the recharge of geothermal water (21.11%) and the more to the discharge (19.38%); F2 contributes the more to the discharge of geothermal water (19.58%) and the least to the recharge (17.82%); F3 and F4 contribute the more to the recharge of geothermal water (20.45% and 20.43%), and the least to the discharge (17.58% and 17.20%). F1 and F5 are the main controlling structures of Xiaobu geothermal water, but the priority of recharge and discharge functions is different. F1 has the largest discharge contribution rate and the smallest variation coefficient, making it the preferred object for expanding geothermal water production; F5 has the largest recharge contribution rate and the largest variation coefficient, making it the preferred object for geothermal water recharge. The results have practical significance for the recharge and expand production of Xiaobu geothermal water.