An experimental study on anisotropy of thermal conductivity in shale

Abstract

Thermal conductivity plays a crucial role in heat transfer and geothermal field distribution in the lithosphere. Understanding the anisotropy of thermal conductivity in shale and its influencing factors is significant for resource evaluation in shale oil and gas areas. In this study, the thermal conductivity of shales in the Songliao and Sichuan basins was measured by laser scanning method. The relationship between thermal conductivity and mineral composition, burial depth and stratigraphy was analyzed to investigate the anisotropy of shale thermal conductivity and its influencing factors. The results show that the thermal conductivity of shale ranges from 1.000 to 2.500 W/(m·K) at different angles. The thermal conductivity of shale is positively correlated with the content of high thermal conductivity minerals such as quartz and increases with burial depth. The anisotropy index of shale thermal conductivity ranges from 0.96 to 2.40. As heat flows through multiple laminae, the interfacial thermal resistance and the influence of the medium cause a decrease in the shale thermal conductivity as the angle between the heat flow direction and the laminae increases. The insights obtained are of reference significance for the accurate modeling of the thermal properties of shale sequences and the study of the geothermal field in shale oil and gas areas.