Discussion on distribution of geothermal resources and locating wells methods of geothermal exploration in Eastern Shandong Province

There are abundant geothermal resources in Eastern Shandong Province. And it’s crucial to select locating wells methods in the processes of geothermal exploration, development and utilization. On the basis of analyzing the distribution characteristics and occurrence rules of geothermal resources in Eastern Shandong Province, and with the experience of geothermal exploration and construction in the study area, the authors used different methods for different geothermal conditions to locate geothermal wells in the typical geothermal exploration areas in Eastern Shandong Province. These methods mainly include natural electric field frequency selection, transient electromagnetic method(TEM), controlled source audio magnetotelluric sounding(CSAMT), electromagnetic sounding and natural radioactivity sounding. The authors also compared the results of different methods. The results show that the geothermal resources in Eastern Shandong Province are mainly distributed near the intersection of the NE, NNE and NW faults, which are deep circulating convective ribbon geothermal resources controlled by faults. Because the thermal reservoirs distribution is mainly controlled by faults, it is appropriate to choose the intersection of two or more faults as the wells locations of geothermal exploration. Natural electric field frequency selection and transient electromagnetic method can better reflect the characteristics of shallow strata and faults. Controlled source audio magnetotelluric sounding can better reflect the development characteristics of deep faults, which is an appropriate method for geothermal exploration in Eastern Shandong Province. In order to avoid the influence of external factors in the process of geophysical exploration, more than two kinds of exploration methods should be adopted to locate geothermal wells.