|
Abstract Geothermal energy is a kind of renewable, durable and stable, green and environmentally friendly energy. The efficient exploitation and utilization of geothermal energy is an important way to promote China's energy transformation. The thermal conductivity and thermal insulation properties of geothermal well cement stone are the key factors to determine the efficiency of geothermal mining. In order to promote the progress of geothermal well cementing technology in China, the research status of high thermal conductivity materials, thermal insulation materials and their mechanisms in geothermal wells at home and abroad are reviewed. The fillers of high thermal conductivity cement in geothermal wells mainly include inorganic high thermal conductivity materials such as graphite, graphene, boron nitride and silicon carbide, and metal fillers such as copper powder, aluminum powder and iron ore powder. The fillers of geothermal well insulation cement mainly include pulverized coal ash, glass beads, rock wool, mineral wool and expanded perlite. The heat transfer efficiency of the material is reduced by creating more voids and pore structures within the material to fill with air. The characteristics of the evaluation method of cement stone thermal conductivity are summarized. Due to the characteristics of short test time, convenient sample preparation and suitable for the test of heterogeneous water-bearing materials, the transient method is more suitable for the thermal conductivity test method of geothermal well cementing cement. Improving the anti-recession, anti-corrosion and anti-permeability of cement stone in geothermal environment is an important research direction of high thermal conductivity cement stone in the future. The selection of cement foaming agent, the combination of organic thermal insulation materials and cement system, and the development of thermal insulation cement system with high strength, low density and strong thermal insulation ability are the main directions of future research.
|
|
Published: 30 December 2024
|
|
|
|
2025, Vol. 0 
