Abstract:This paper is the result of geothermal survey engineering.
[Objective] The Datong Basin is a Cenozoic rifted basin with superior geothermal geological conditions. But due to the scarcity of geophysical and drilling data in the basin, the research on the basin structure, sedimentary stratigraphy distribution, geothermal geological characteristics and resource evaluation is relatively weak, which partly restricts the understanding of the potential of the geothermal resources of the Datong Basin, as well as the exploitation and utilization of the geothermal resources. [Methods] In this paper, the new 2D seismic, regional geological survey, drilling and logging wells and other oil and gas and exploration data are comprehensively applied to carry out the research on the geological structure, fracture, sedimentary stratigraphy, and geothermal geological characteristics of the northern Datong Basin, and then evaluated the potential of geothermal resources, estimated the amount of geothermal resources, and pointed out the favorable zones of geothermal resources. [Results] The Datong Basin is divided into five tectonic units:the Huairen sag, the Sanganhe sag, the Yingxian sag, the Huanghualiang low uplift and the Sanganhe low uplift. The northern part of the basin (within Datong City) is characterized by good geothermal geological conditions and resource potentials, with the development of two sets of thermal reservoirs:Neocene sandstone and Basement rock, and a thick Quaternary thermal cover, and the Cenozoic is characterized by strong tensional and volcanic activities, and is generally at the high value of geothermal heat flow. The area is in the high value of geothermal flow, and has the potential of geothermal resources of Neocene sandstone and Basement rock, with a total static resource of about 68.8×1015 kJ, which is equivalent to about 2.347 billion tons of standard coal. [Conclusions] The comprehensive evaluation concludes that the western part of Huairen sag and the northern part of Sangganhe sag in Datong Basin are hydrothermal geothermal resource first-class areas, which are favorable target areas for geothermal exploration and development, with the buried depth of thermal reservoir more than 2000 m, the predicted average water temperature greater than 60℃, and the inflow volume of a single well up to 60 m3/h. The northeastern part of Huairen sag and the southwestern part of Sangganhe sag are geothermal resource second-class areas. The geothermal resources of Huanghualiang low uplift and Sangganhe low uplift area are relatively poor.