LI Pengwei, HE Zhiliang, FENG Jianyun, ZHANG Ying, Chen Xinjun, WU Xiaoling
In recent years, with the situation of air pollution in the eastern part of China becoming a more and more serious concern, the development and the utilization of geothermal resources in this area has been put on the agenda. It is recognized that the wellhead temperatures and the water productions of geothermal wells in different areas are different, and some geothermal wells are characterized by a low temperature or water production, which seriously affects the development of geothermal industry. In order to find out the output characteristics of sedimentary geothermal reservoirs in the eastern part of China, the main sedimentary geothermal reservoirs in this area are initially investigated based on the analysis of the wellhead temperature and the single-well yields of 188 wells, which have been and are being exploited in this area. The results show that the sedimentary geothermal reservoirs in the eastern part of China are characterized by the warm-hot water and the hot water, and dominated by the mediate and high yields, with the Jixian system Wumishan formation and the Cambrian-Ordovician system Karstic and fractured reservoirs having the highest yields, and Neogene system Guantao and Minghuazhen formation sandstone reservoirs having lower yields. Among the reservoirs, the Karstic and fractured reservoirs see a wider variation in yields, suggesting a more heterogeneity. According to the results, several suggestions are made as follows:(1) diversified and stepwise utilization should be actively considered, to make a full use of the efficiency of the geothermal resources; (2) Jixian system Wumishan formation and Cambrian-Ordovician system Karstic fractured reservoirs should be preferentially considered in the geothermal exploitation and utilization, especially in the areas where the basement rocks are shallowly buried; (3) heterogeneity of the Karstic and fractured reservoirs and its relationship with the yields should be studied, in order to find reservoirs with high water production.
