Potential Evaluation of Geothermal Resources: Exemplifying Xi'An Yanchang Petroleum Xihau Residential District As An Example

Weihe basin has a long history of geothermal development and utilization， HuaQingChi hot spring was famous all over the world as early as the Tang Dynasty (700 BC). There are some key factors that affect the evaluation of geothermal resources, such as heat sources, thermal reservoirs (sand body thickness, porosity, permeability), geothermal field, etc. This paper takes the Xi’an Sag-Yanchang Petroleum Xihua District in the Weihe Basin as an example, based on the collection of predecessor data, we analyze the geothermal field characteristics, thermal reservoir characteristics and geothermal resources by using formation temperature measurement, well logging, and core analysis data. We also use a variety of parameters to optimize the evaluation of the favorable areas of the thermal reservoir. The research results show that the geothermal gradient of Yanchang Petroleum Xihua District is 3.56℃/100m, which is a geothermal anomaly area, and the Zhangjiapo and Lantian Bahe Formations in Xihua District have developed interbeds of sand and mudstone, with sand thickness ranging from 40 to 140m, and average porosity at 15.68% ~ 30.3%, the sand thickness, formation heat, water content and total heat of the Lantian-Bahe Formation is higher than those in the Sanmen and Zhangjiapo formations, and the geothermal development conditions are the best; The Lantian Bahe Formation should be selected as the main target zone for geothermal development in Yanchang Petroleum Xihua District. It is suitable to adopt the deep-buried tube heat exchange method.