Recently, the Gaoxin area geothermal DZ01 well cement slurry of China Coal Science and Technology Group Xi'an Research Institute back to the ground, which marking the single well heat exchange mining of China's middle and deep geothermal energy was successfully completed, and the green development and utilization of geothermal energy technology achieved new breakthroughs.
Geothermal energy is a green, environmental and renewable clean energy source with large reserves. It has wide distribution, stable and reliable characteristics. As China's environmental protection pressures increase, the proportion of coal consumption continues to decline, and the pace of energy cleanliness is also accelerating. In January 2017, China issued the “13th Five-Year Plan for Geothermal Energy Development and Utilization” for the first time, and vigorously promoted the development and utilization of geothermal energy. At present, geothermal energy development mainly includes shallow geothermal, conventional hydrothermal geothermal and dry hot rock geothermal, and the medium and deep geothermal concentric tubular heat transfer technology developed in recent years is a kind of “heat only”. The green development method of “not taking water” compensates for the shortage of shallow geothermal (ground source heat pump) and hydrothermal geothermal.
The DZ01 well constructed by Xi'an Research Institute is designed for vertical wells. The casing type completion, the well depth is 3518m, and the well logging temperature is 129.1°C. The green development method of borehole heat transfer in the well has been used to create a medium-deep geothermal energy single well concentric tube in China. The maximum well depth of heat exchange and the bottom hole temperature are also the highest in such geothermal wells in China. At the same time, Xi'an Research Institute has continuously innovated and independently developed new technologies and equipments. The high-heat-conducting cement-based composite materials, new composite thermal insulation inner tubes, and full-well distributed optical fiber ground temperature monitoring, achieving new breakthroughs in key technologies and improving Energy efficiency, reduced cost, enhanced applicability of deep geothermal borehole heat transfer technology and increased the value of promotion.
On this basis, Xi'an Research Institute will continue to carry out technical research and complete the demonstration project of deep geothermal energy clean-up transformation of existing building heating, continuously promote the technological progress of the industry, and make greater contributions to the green development of geothermal resources in China.
