Survey And Analysis Of Geothermal Formation Geological Conditions On The Western Margin Of Yishu Fault Zone In Central Region Of Changle County

In this paper, the main purpose of the study is to delimit the ambit of favorable geological conditions through Analysising the geothermal resources formation geological conditions in Yishu fault zone of the western margin in the central region of Changle County, and provide a basis for seeking for exploration and utilization of geothermal resources. Based on research of the geothermal geological conditions in this area, we think that it is provided with a good geothermal generation environment and occurrence conditions in this area in theory. And we also think that the geothermal formation in the area is closely related to the stratigraphic structure and the fault structure. Considering with the water abundance of Neocene basalts, paleogene Wutu group, Cretaceous system and intrusive rocks of paleoproterozoic, the uncertainty of the strata thickness and the distribution characteristics of the regional geothermal resources and the other factors, we decided to the key areas of this survey is both sides of the Tangwu-Gegou fault, especially the intersections of secondary faults with the Tangwu-Gegou fault. The two geothermal anomaly areas, Chunyu anomaly area and Liangjiazhuang anomaly area are delimited by the integrated use of geological survey, ground temperature measurement, geophysical prospecting, drilling, etc. in the favorable area selected. They are located near Liangjiazhuang Qiaoguan Town and Pangjia Chunyu. They have low resistance anomalies in depth of1400m-2000m. They are of a certain size with600m-1000m width. The two geothermal anomaly areas are considered to be the intersections of the Tangwu-Gegou fault&its branches, as well as east-west trending faults analysising geologic formations nearby. They are speculated to have certain water conductivity and water storage space, and to be geothermal resources formed the favorable position. They are classed as Banded geothermal reservoir in the geothermal reservoir structure. The geothermal reservoir is determined as Cretaceous Qingshan Group andesite. The heat water in geothermal reservoir is becoming from the shallow cool water penetrated into geothermal reservoir by way of geologic structure heated by deep geothermal. And thicker upper neocene and paleogene argillaceous rocks, sandstone and cretaceous Dasheng Group sandstone and clay stone and so on, become a good cap rock. Combined with regional geological data, it is deduced that the geothermal conceptual model of water resources is the earth’s crust deep heatingâ†'deep fracture conductivityâ†'low thermal conductivity layers trap heatâ†'lateral subsurface runoff and fault fracture zone water supplying. Geothermal reservoir types is a deep circulation convection banded geothermal reservoir.On the basis of the conceptual model of geothermal water resources, the three advantage locations of geothermal well are determined. They are Chunyu predicting area (Changrel) and Liangjiazhuang predicting area (Changre2). And2geothermal well locations are recommended in Chunyu predicting area. The geothermal well location in Liangjiazhuang predicting area is preferential recommended. It is predicted that the depth of the well is1800±200m. The tempretures of geothermal reservoir in1800m depth in Chunyu predicting area and Liangjiazhuan predicting area are predicted to be41±5℃and61±5℃. The water inflows of the predicting geothermal wells are going to be30m/h±10m3/h. The geothermal water salinity is predicted to be5g/1-10g/l. And hydrochemical type is predicted to be sodium chloride water type water or chloride sulfate type. The study has carried on the further exploration in geothermal prospecting in central region of ChangLe. Preliminarily the three proposed well locations have been determined. This provided the important basis for the exploration and development of the geothermal resources in this area.