Research on Economic Length of the Horizontal Section of U-Shaped Geothermal Wells Based on Net Present Value

Vigorously developing non-fossil energy, including geothermal energy, will lead to carbon neutrality in the future. Based on the technological advantages of oil and gas companies, increasing investment in geothermal energy is a long-term strategy for oil and gas companies and the key to the transformation of such companies into integrated energy companies. The development and use of geothermal resources more effectively and economically require careful analysis and research. A U-shaped geothermal well is formed by joining a vertical well and a horizontal well. Based on the relevant theories of fluid mechanics, thermodynamics, heat transfer, and drilling engineering, this work establishes a mathematical model of U-shaped geothermal wells for heat extraction and uses experimental test data to verify the model. Through coupling technology and economy, this work develops an economic length model for the horizontal section of a U-shaped geothermal well based on the net present value method under multi-parameter combinations. This study provides a set of technical and economic evaluation methods for the optimization of economical and efficient heat extraction in a U-shaped geothermal well. It is of great significance to the realization of the Chinese national energy goal of carbon neutrality.