Terrestrial Heat Flow in the Qagan Sag, Inner Mongolia

Abstract

The Qagan sag has the largest oil and gas exploration potential in the Inggen‐Ejin Qi basin, Inner Mongolia. The terrestrial heat flow research is still blank in the Qagan sag and rest of the Inggen‐Ejin Qi basin, which seriously restricts the oil and gas resource assessment in the basin. In this work, 107 rock thermal conductivity data of 19 wells were measured and in‐situ corrected, and the rock thermal conductivities of each stratum were obtained by the union average formula. Based on the 9 wells' temperatures, combined with the above rock thermal conductivity data, the geothermal gradients and terrestrial heat flow were calculated. The results show the Qagan sag has the characteristics of the medium temperature field between tectonically stable and active regions, with an average thermal gradient of 33.6 °C/km and an average terrestrial heat flow value of 74.5 mW/m2. This work provides the geothermal data for oil and gas resource assessment of the Qagan sag and other sags of the Inggen‐Ejin Qi basin.