GEOLOGIC NOTE
Hydrocarbon basins offshore China under multiplate interactions, by Weilin Zhu and Yuhong Xie
Chinese offshore basins produced more than 1.6 million bbl of oil equivalent per day in 2024. They represent one of the largest offshore oil and gas production bases in the world and are a significant contributor to provide energy to fuel China’s economic growth. This study synthesizes decades of exploration achievements to elucidate genetic links and interactions leading to the development of continental rifts, back-arc, and strike-slip basins. Understanding the geological evolution history has been pivotal to the success of hydrocarbon discoveries and development in these basins and can hopefully provide some lessons for oil and gas exploration and exploitation for other offshore basins around the world.

ARTICLES
Western offshore Myanmar: New insights on the Ayeyarwady River as the fairway for Pliocene-Pleistocene sandstone, by Kyaw Zin Oo, Ko Ko, Kyaw Soe Win, Aung Zayar Myint, Zaw Win Aung, Su Mon Aye, Thant Zin Aung, Kyaw Naing Oo, Tin Tin Naing, and Eloi Dolivo
Until 2012, the western Myanmar waters area was deemed unattractive for hydrocarbon exploration due to the apparent absence of a nearby large river system; hence, there was a perceived low chance of finding reservoirs. This paradigm underwent a transformative shift during the last decade, with successful hydrocarbon exploration in offshore block A-6. The authors integrated interpretation of two- and three-dimensional seismic data, well logs, petrography, heavy-mineral analysis, U-Pb zircon age dating, and regional geologic context indicates that a Pliocene-Pleistocene fan system received sediment from the proto-Ayeyarwady-Chindwin river, which flowed east to west through a wide breach in the unstable continental slope of block A-6 during the Late Miocene.

Quantifying sources of gas hydrate through diagenetic modeling, by Zichen Wang, Xinyu Ming, Zhaohui Xu, and Lei Jiang
Determining the sources of methane for hydrate formation is critical to hydrate exploration and to understanding its implications for the global carbon cycle, climate change, ocean chemistry, and biosphere throughout Earth’s history. However, quantifying the gas sources for ancient hydrate records presents a considerable challenge due to the absence of direct evidence. In this study, the authors simulate the variations in authigenic carbonates precipitation associated with anaerobic oxidation of methane under different rates and specific methane source scenarios. Their findings suggest that the observed changes are best explained by varying ratios of biogenic methane versus thermogenic methane and differences in anaerobic oxidation of methane rates.

Fault seal behavior in porous sandstones: A case study from the Bozhong subbasin, Bohai Bay Basin, China, by Xianqiang Song, Zhida Liu, Xiaofei Fu, Haixue Wang, and Peng Xu
Faults in porous sandstone were previously considered ill-suited for sealing hydrocarbons, which resulted in many promising fault-related hydrocarbon exploration targets being overlooked. This paper investigates the sealing properties of faults within porous sandstone in the Bozhong subbasin using well drilling data and repeat formation test pressure measurements from both sides of the faults. The findings highlight the importance of considering stress effects, in addition to clay content, when evaluating the sealing capacity of faults in sand–mudstone sequences. Neglecting the role of stress may lead to underestimation of the fault sealing potential, particularly for faults in porous sandstones.