ARTICLES
Shale facies in the Mesoproterozoic Beetaloo Sub-basin, Northern Australia—Experiment-based assessment of depositional conditions for the world’s oldest gas shale, by Juergen Schieber, Sandra Menpes, and Tim J. Munson
Interpreting depositional settings of ancient shales relies on careful facies analysis, recognition of primary sedimentary structures and textures, and the “readout” they provide with regard to physical, chemical, and biological processes at the seabed. The authors link detailed core descriptions and petrography of Mesoproterozoic shales from drillholes in the Beetaloo Sub-basin of the McArthur Basin, Northern Territory, Australia, to identify likely underlying physical, chemical, and biological processes and process parameters in this very old succession where the factors controlling organic matter preservation and source rock formation might be quite different from those in Phanerozoic and younger counterparts.

Hydrocarbon accumulation processes and model controlled by overpressure evolution of the DF1-1 diapir in the Yinggehai Basin, South China Sea, by Zonglin He, Fang Hao, Jinqiang Tian, Lin Hu, Gaowei Hu, Yazhen Zhang, Lu Yang, Shang Xu, and Qingfeng Meng
Fluid diapirs are formed through the upward intrusion of fluids along fracture zones, with hydraulic fracturing and fluid charge occurring at the uplift point of the overpressure interface. The DF1-1 diapir is the most typical fluid diapir in the Yinggehai Basin, South China Sea, characterized by multilayer gas accumulation. The aim of this paper is to examine the gas charge history of the DF1-1 diapir and clarify the coupling relationship between the overpressure evolution and the gas charging processes, build the dynamic gas accumulation process, and ultimately provide an accumulation model for further exploration.

Assessing rock physics models for total organic carbon estimation in lower Goru Formation: Case study on a shale gas reservoir in Pakistan, by Ghulam Mohyuddin Sohail, Muhammad Umair, Ahsan Mehmood, and Shahid Ejaz
Total organic carbon is essential for evaluating shale gas reservoirs and estimating hydrocarbon reserves. Laboratory TOC measurements are accurate but time-consuming, costly, and often limited to specific depths. This study evaluates rock physics models for predicting TOC in the lower Goru Formation, Lower Indus Basin, Pakistan, where core samples are unavailable. The research addresses challenges in selecting input parameters for rock physics models with limited measured TOC and provides valuable insights into TOC estimation from wire-line logs, enhancing the understanding of shale gas reservoir characterization globally.

Carrier bed plays of the Cambrian Qiongzhusi Formation in the Sichuan Basin, China: Exploration practices and significance, by Tonglou Guo, Enze Wang, and Maowen Li
In conventional petroleum systems, carrier beds are traditionally regarded as pathways for petroleum migration. However, petroleum geologists are increasingly recognizing the exploration significance of carrier beds as potential reservoirs, introducing the concept of the carrier bed play. This study focuses on the silty shale of the Qiongzhusi Formation in the Jingyan-Qianwei area in the southwestern Sichuan Basin. The authors systematically characterize its geological features and, through comparison with deep-water organic-rich shale gas reservoirs combined with production dynamic data, provide new insights into the accumulation mechanisms and development characteristics of carrier bed plays.

MEMORIAL
Paul Michael Gerlach - October 20, 1952-May 15, 2026