The occurrence pattern of natural hydrogen in the Songliao Basin, PR China: Insights on natural hydrogen exploration

The exploration of natural hydrogen offers a promising path towards achieving energy transition and environmental protection. To gain knowledge on the occurrence of natural hydrogen in the Songliao Basin, rock samples from the hydrogen-rich intervals in the Denglouku Formation and Yingcheng Formation of Well SK-2 in the Songliao Basin were analyzed using XRD, SEM, nitrogen adsorption, and high-pressure hydrogen adsorption measurements (under 25 degrees C, 0-18 MPa). The results revealed that hydrogen adsorption mainly depended on pore structure. Hydrogen predominantly existed in adsorbed form in mesoporous and microporous pores. The amount of adsorbed hydrogen in rocks decreases with elevated temperature and increases with pressure. Hydrogen migration to the for-mations primarily occurred through faults, and sandstone mainly contained free hydrogen. Understanding the occurrence and accumulation mode of natural hydrogen in Well SK-2 contributes to the development of exploration methods and utilization of this valuable resource. (c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.