Current situation and prospect of exploration and research on tar-rich coal resources

Tar-rich coal is a kind of coal-based oil and gas resource with a solid foundation for large-scale development. However, its resource exploration still faces challenges, including insufficient universality of tar yield prediction methods, low exploration degree of oil-rich coal resources, and an imperfect evaluation system for the development potential of oil-rich coal resources. In order to effectively support the development of tar-rich coal resources, the current research status of tar yield prediction and resource development potential evaluation of tar-rich coal is systematically reviewed. The results show that tar yield is the sole criterion for determining tar-rich coal. Four types of tar yield prediction methods have been initially formed, namely, experimental determination techniques such as Gekin low-temperature dry distillation, geophysical prediction techniques based on logging information such as compensated density and natural potential, prediction techniques based on coal, rock and coal quality information, and comprehensive prediction techniques based on multi-information fusion. The highest prediction accuracy can reach more than 80%. The distribution range of tar-rich coal resources in major coal seams in regions such as the Tuha Basin, Santanghu Basin, Ordos Basin, Ningxia and Huainan was predicted, the amount of oil-rich coal resources was calculated, and the prototype of the evaluation index system for resource development potential was formed. In the future, tar-rich coal resources will become an important supplement to the country’s oil and gas resources, providing a safety net for China’s energy security. The exploration of tar-rich coal resources needs to fully integrate conventional coal resource exploration techniques to enhance the degree of geological condition exploration, fully combine conventional exploration methods to improve the accuracy of tar yield prediction and the universality of technology, fully integrate modern new testing methods to enhance the identification of physical property characteristics of tar-rich coal, and fully utilize modern artificial intelligence technology and high-level computing power to construct geological models. Propose the exploration technical idea of “high-precision exploration technology to study the geological structural characteristics, multi-means to predict the tar yield, multi-method to test the physical property characteristics and multi-information fusion to construct geological model”. Build a technical system for the exploration of tar-rich coal resources, enhance the degree of exploration, and provide geological support for the green, low-carbon and sustainable development of tar-rich coal.