Time-stratigraphic correlation of the Spiro sandstone, Arkoma Basin, southeastern Oklahoma, by Brian W. Horn. The Pennsylvanian Wapanucka Limestone and Spiro sandstone comprise a third-order genetic sequence containing sediments and surfaces that record marine shallowing and deepening during the final stages of passive-margin deposition and the onset of foreland basin development in the Arkoma Basin. Time-stratigraphic correlation from detailed facies analyses identifies a new correlation of the Wapanucka Limestone and Spiro sandstone, creating a higher-resolution framework for prediction of reservoir presence, reservoir connectivity, and compartmentalization in developed fields, in addition to a new depositional model predicting untested exploration pathways.

Controls of shale gas enrichment and high yield in the lower Cambrian Niutitang shale of the Yichang area, southern China, by Qiyang Gou, Yuxin Hao, Shang Xu, Zhangxing Chen, Keyu Liu, Zhengbin Wu, Bo Gao, Yangbo Lu, and Qiqi Li. The overmature lower Cambrian Niutitang shale in southern China is considered a promising shale play. Drilling results have often fallen short, however, with limited industrial gas flow confined primarily to the Sichuan Basin. This study investigates the recent shale gas breakthroughs in the Yichang area, located outside the basin. Gas generation potential, storage capacity, preservation conditions, and the impact of advanced engineering techniques are comprehensively examined. This research highlights the potential for ancient shale accumulation in complex tectonic regions and provides valuable insights for developing low-pressure shale gas reservoirs.

Stratiform-dolostone flow units in the Williston Basin: Stratigraphic, porosity•permeability, and oil-producing relationships, by David M. Petty. Oil-productive stratiform-dolostone flow units in the Williston Basin occur in Mississippian, Devonian, and Ordovician formations. Sediment deposition occurred in low-energy, epeiric-shelf settings characterized by muddy carbonate and evaporite accumulations. The stratiform-dolostone flow units of this study are mappable stratigraphic units with laterally and vertically continuous porosity that parallel fourth- and fifth-order stratal surfaces and are characterized by predictable rock properties. Although oil-productive stratiform-dolostone flow units occur in strata of different ages and with different depositional styles, they share many common characteristics that suggest some common origins.

Diagenesis in the middle•upper Cambrian Xixiangchi Formation from mineralogy and fluid inclusion analysis: Insight to fluid history and basin evolution, by Xiuyan Liu, Junjia Fan, Jacques Pironon, Hua Jiang, Honghan Chen, Xuesong Lu, Thomas Gentzis, Seare Ocubalidet, and Mehdi Ostadhassan. The Anyue gas field contains deeply buried multilayer carbonate reservoirs and is a prominent natural gas producer in China. Although prior research mostly focused on the Sinian and lower Cambrian reservoirs, the middle-upper Cambrian Xixiangchi reservoir remains less explored. A comprehensive grasp of the diagenetic fluid history of the Xixiangchi Formation has yet to be achieved. This study uses a multifaceted approach, incorporating various petrographic observations, fluid inclusion microthermometry, Raman spectrometry, one-dimensional basin modeling, and fluid pressure-temperature modeling to unravel the basin evolution with a specific focus on the fluids.