Fluid–space–solid three-terminal thermal storage classification

Abstract

Thermal storage has not yet been classified in a unified way. By analyzing the factors of thermal storage and the interactions of fluids, spaces, and solids, this study proposes a three-level classification scheme based on fluid–space–solid thermal storage and dissects the main thermal storage types in the Eryuan, Midu, and Lancang areas of Yunnan Province. The results show that the hydrothermal-karst-carbonate reservoirs of the lower Devonian Kanglang Formation, Carboniferous, and Lower Permian are the main reservoirs in the Eryuan area, the hydrothermal-fracture-carbonate reservoirs are Carboniferous and Lower Permian in the Midu area, and the hydrothermal-fracture-metamorphic reservoirs of the Manlai and Huimin formations are the main reservoirs in the Lancang area. These reservoirs are characterized by high porosity and permeability, high thermal conductivity, high thermal diffusivity, and high specific heat capacity. The classification scheme is systematic, comprehensive, and unified, is capable of conveying multiple information points, and provides a new method for geological exploration personnel to analyze the thermal storage characteristics.