Exploration of Heat Extraction Characteristics and Cost of Coaxial Casing Wells for Medium to Deep Coaxial Buried Heat Exchanger

Exploration of Heat Extraction Characteristics and Cost of Coaxial Casing Wells for Medium to Deep Coaxial Buried Heat Exchanger

With the increasing demand for energy, geothermal resources, as a clean and renewable energy source, are gradually attracting people's attention. As an important means of developing geothermal resources, the heat transfer performance of geothermal wells directly affects the utilization efficiency of geothermal energy. In mid to deep geothermal wells, coaxial sleeve buried tube heat exchangers are becoming an important choice for geothermal resource development due to their structural characteristics and advantages.

1、 Heat extraction characteristics of mid to deep coaxial sleeve buried tube heat exchanger

The coaxial sleeve buried tube heat exchanger consists of two layers of sleeves, the outer sleeve is used for heat exchange with the soil, and the inner sleeve serves as a channel for fluid to transfer heat. This structural form has the advantages of high heat transfer efficiency, small footprint, and easy installation and maintenance. In mid to deep geothermal wells, coaxial sleeve buried tube heat exchangers extract underground thermal energy through heat exchange between circulating media and underground thermal storage.

In practical applications, the heat extraction characteristics of mid to deep coaxial sleeve buried tube heat exchangers are influenced by various factors. Firstly, the thermal properties of soil, such as thermal conductivity and specific heat capacity, have a significant impact on the heat transfer efficiency of heat exchangers. The better the thermal properties of the soil, the higher the heat transfer efficiency of the heat exchanger. Secondly, the flow characteristics of fluids, such as velocity, flow rate, temperature, etc., can also affect the heat transfer efficiency of heat exchangers. Reasonable fluid flow characteristics can improve the heat transfer efficiency of heat exchangers. In addition, the structural parameters of coaxial sleeve buried tube heat exchangers, such as inner and outer diameters, length, etc., also have a significant impact on heat transfer performance. By optimizing structural parameters, the heat transfer efficiency of the heat exchanger can be further improved.

2、 Cost exploration of drilling coaxial casing wells

The cost of drilling coaxial casing wells is influenced by various factors, including geological conditions, depth of field, wellbore diameter, casing material, manufacturing process, etc. Geological conditions are one of the main factors affecting the cost of drilling wells. Under hard geological conditions, the difficulty and cost of drilling wells will correspondingly increase. Depth of field and wellbore diameter are also important factors affecting the cost of drilling wells. The deeper the depth of field and the larger the wellbore diameter, the more drilling equipment and materials are required, and the higher the cost.

The casing material is an important component of drilling coaxial casing wells, and its selection will directly affect the cost of drilling. Common casing materials include steel pipes, cast iron pipes, plastic pipes, etc. Steel pipes have high strength and durability, but their cost is also relatively high; Cast iron pipes have lower costs, but poor corrosion resistance; Plastic pipes have good corrosion resistance, but their strength and durability are relatively low. Therefore, when selecting casing materials, various factors need to be comprehensively considered to achieve cost-effectiveness.

The manufacturing process is also one of the important factors affecting the cost of drilling coaxial casing wells. The manufacturing process can improve drilling efficiency and quality, and reduce drilling costs. Meanwhile, reasonable construction organization and management can effectively reduce the cost of drilling wells.

In summary, the mid to deep coaxial sleeve buried tube heat exchanger has broad application prospects in geothermal resource development due to its structural characteristics and advantages. In practical applications, it is necessary to comprehensively consider various factors to achieve heat transfer performance. At the same time, the cost of drilling coaxial casing wells also needs to be fully considered and controlled to achieve economic and efficient development of geothermal resources.