Genetic analysis and resource evaluation of the Xining geothermal field in Qinghai Province

Abstract: Based on available drilling data of the Xining geothermal field and regional geothermal and geological data in combination with research results of recent exploration projects, the authors analyzed burial conditions, recharge and runoff discharge conditions, geo-temperature field and geochemical characteristics of the Xining geothermal field, and pointed out that the Xining geothermal field mainly has terrestrial heat flow as the heat source, the strata with low thermal conductivity accumulate the heat, the deep circulation gradual heating forced convection mechanism causes the water control and heat control, dominated by basin conduction type planar thermal reservoir, with some characteristics of fracture convective banded thermal reservoir. The thermal reservoir method was adopted to conduct evaluation of the geothermal resource quantity of the Xining geothermal field. The heat quantity accumulated in the thermal reservoir of the geothermal field is 9.343×1014 kJ，and the annual exploited heat quantity of the geothermal field calculated by the average well deployment method is 1.12×1012 kJ, equivalent to 3.78×104 t standard coal. According to the scale classification, the Xining geothermal field should belong to the medium type low-temperature geothermal field. The distribution regularity and resource quantity of the Xining geothermal field have been ascertained, which provides an important basis for the rational development and utilization of geothermal resources in the Xining geothermal field.