Geothermal Energy Exploration By Use Of Geophysical Methods In Taoshan Area Of Heilongjiang Province

Taoshan area is at southeast in Tieli city of Heilongjiang province. Because Tieli city is located in northern Latitude47degrees, the period of keeping warm with coal is as long as6months. Keeping warm with coal not only consumes a lot of coal, but also pollutes atmosphere environment. Therefore, the government of Taoshan town pays more attention to local geothermal energy resources. The aim is to decrease the coal consumption, reduce the emissions of harmful air like CO2and SO2and develop a place economy.Taoshan area also has the good potential of geothermal energy resources..In2001, Tao one well with the depth of1907meters had been finished in the south of Taoshan town and at the north shore of Hulan river. During drilling of Tao one well, groundwater overflew from the mouth of well. After precipitating of drilling mud, groundwater flew with5m3/h from the mouth of well. Water temperature at the mouth of well was39℃. After washing well, the yield of water was300m3/d and water temperature was60℃.The type of water chemistry was HCO3-Ca·Na. The total dissoloved solid was1.1g/1. In order to make well use of local geothermal energy resources, the government of Taoshan town trusted exploration of geothermal energy resources by use of gravity magnetic electric integrated geophysical methods to ECE. So, gravity magnetic electric six surveying lines of the total length of31.81kilometers had been arranged in the research area of46square kilometers.Based on the data of geology, drilling well, logging, physical property and gravity magnetic electric in the research work and its surrounding areas, geological conditions of geothermal energy resources in the area of Taoshan have been researched. The achieved results are as follows:1、 There are two faults in the research work. One is named Taodong fault(F1), the other is named Taoxi fault(F2). F1is a chief fault with the NNE trend. F2is a secondary fault with NNW trend. Strata of Jurassic and Cretaceous develop in the west of F1. Granite and Paleozoic metamorphic rocks develop in the east of F1.2、 The carrier of geothermal energy is groundwater in the research work. There are two types of heat reservoir beds, fracture zone, sandstone and siltstone. Heat reservoir bed of fracture zone exists in the granite and in the contact strip. Heat reservoir bed of sandstone and siltstone exists in Quantou Formation. Reservoir conditions of Quantou Formation are better. The total depth of Quantou Formation’s heat reservoir is about100meters. There are two geothermal energy prospect areas in the research work, I grade prospect area in the southern depression and Ⅱ grade prospect area in the northern depression.3、The average ground temperature gradient is25℃along the Logging section of200-1880meters in the research work. The ground temperature gradient is also higher. The ground temperature gradient increases in low granite section obviously. These phenomena mentioned above prove conditions of ground temperature better in Taoshan area. Because the depth of geothermal energy resources is less than2000meters, the cost of exploitation is low. Taoshan area is a prospect area of low temperature geothermal energy resources. The geothermal energy resources can be made well use to service production and living.4、Three drilling wells have been designed in research work. The well depth is also1800meters. The suggestion is that TR3well is drilled first. The geothermal energy of TR3well will be better than that of Tao one well.