Article
Energy & Fuels
Dongjun Song, Chenjun Wu, Jincai Tuo, Xiaoqi Wang, Mingfeng Zhang, Wei He, Zunqing Ma, Long Su, Xu Jin
Summary: The study found that carbon isotope anomalies in shale gas exhibit different characteristics at different stages of thermal maturation, with partial carbon isotopic reversions produced in laboratory simulations but complete reversions not reproduced. These findings differ slightly from the natural conditions where shale gas typically exhibits full carbon isotope reversal.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2021)
Article
Geosciences, Multidisciplinary
Xing Wang, Hui Tian, Haifeng Gai, Zijin Wu, Qin Zhou, Sui Ji, Tengfei Li, Xianming Xiao
Summary: This study investigates the gas generation potential, chemical signatures, and carbon isotopic compositions of natural gas derived from solid bitumen in an overmature hydrocarbon system. The results indicate that methane primarily originates from secondary cracking of wet gas and has lighter carbon isotopes. Furthermore, there are significant differences in the generated gas between closed and semi-open systems.
MARINE AND PETROLEUM GEOLOGY
(2022)
Article
Energy & Fuels
Jingkui Mi, Wei Wu, Di Zhu, Ziqi Feng
Summary: The geochemical statistics suggest that the wetness of over-mature shale gas is related to carbon isotope reversal, and the substantial cracking of CH4 plays a crucial role in this process. The experimental results also show that temperature affects the delta C-13(1)-delta C-13(2) values. Furthermore, two geochemical indices have been proposed to indicate CH4 substantial cracking based on the study of over-mature shale gas in the Sichuan Basin.
Article
Geochemistry & Geophysics
Domokos Gyore, Magali Pujol, Stuart M. V. Gilfillan, Finlay M. Stuart
Summary: Unconventional hydrocarbon resources, such as shale oil/gas and coal-bed methane, have become increasingly important over the past decade. The Vaca Muerta Shale in Argentina contains a significant amount of shale gas, but its exploitation is complicated by elevated CO2 concentrations. Isotopic analysis of CO2-rich gases in the region suggests that CO2 may have originated from magmatic activity and mixing with crustal hydrocarbon-rich gases. Additionally, gases below the shale show evidence of mixing with groundwater-derived noble gases prior to entering the shale formation.
Article
Geosciences, Multidisciplinary
Yunyan Ni, Dazhong Dong, Limiao Yao, Jianping Chen, Xing Liang, Fei Liu, Jian Li, Jinhao Guo, Jinliang Gao
Summary: This study analyzed gases from shale gas fields in the southern Sichuan Basin to investigate their geochemical characteristics and origins. The gases belonged to shale gas from the Upper Ordovician-Lower Silurian shale and were dominated by methane. The isotopic compositions of carbon indicated high thermal maturity and contributions from organic matter. The study found a complete carbon isotopic reversal trend and highlighted the importance of understanding the geochemical characteristics of shale gases for future exploration.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Geosciences, Multidisciplinary
Xuewen Shi, Shujuan Kang, Chao Luo, Wei Wu, Shengxian Zhao, Di Zhu, Huanxu Zhang, Yang Yang, Zhenglu Xiao, Yong Li
Summary: This paper presents a study on the Longmaxi Formation in the Sichuan Basin, which is a significant shale gas producing formation in China. The research provides carbon isotopic data that suggest better shale gas exploration potential at the bottom of the Longmaxi Formation. The study also compares the exploration prospects in different areas and recommends further drilling based on the presence of oil cracking gas resources and better reservoir conditions.
JOURNAL OF ASIAN EARTH SCIENCES
(2022)
Article
Geosciences, Multidisciplinary
Shaojie Li, Xiaowen Guo, LunJu Zheng
Summary: Hydrous pyrolysis experiments were conducted to study the carbon-hydrogen isotopic systematics of hydrocarbon gas. The presence of formation water affected the isotopic ratios of methane, ethane, and propane in the gas. The isotopic ratios increased with thermal maturity and showed quadratic correlations with vitrinite reflectance values. Supercritical water did not significantly affect the isotopic partitioning behavior. Partial isotopic reversals were observed during the oil and gas generation stages, likely due to gas mixing.
MARINE AND PETROLEUM GEOLOGY
(2022)
Article
Geochemistry & Geophysics
Xiaoqiang Li, Juske Horita
Summary: The phenomenon of laboratory pyrolysis experiments producing wetter gases than those in natural reservoirs has long been recognized and debated in the investigation of natural gases in sedimentary basins. This study compares the pyrolysis of Woodford Shale with previous results from the Arkoma Basin to explore the discrepancy. The analysis of gas and isotopic compositions suggests that the generation of light hydrocarbons involves uni-directional cracking reactions, exchange reactions with water, and reversible reactions among light hydrocarbons and other H-containing volatiles. The findings highlight the importance of compound-specific and position-specific isotope analysis in understanding geological and biodegradation processes.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2022)
Article
Energy & Fuels
Wenbiao Li, Junqian Li, Shuangfang Lu, Guohui Chen, Xiaoting Pang, Pengfei Zhang, Taohua He
Summary: Gas-in-place content and gas-adsorbed ratio are crucial parameters for resource potential assessment and production strategy optimization in unconventional gas resources. The carbon isotope fractionation model provides a powerful tool in evaluating the mechanism of isotopic fractionation during natural gas transport. The study in the Jiaoshiba area of China showed a positive correlation between methane degassing volume and TOC content, and an underestimation of shale gas resources by the traditional USBM method.
INTERNATIONAL JOURNAL OF COAL GEOLOGY
(2022)
Article
Geochemistry & Geophysics
Bojiang Fan, Liang Shi, Xia Wang, Chi Wang, Yating Li, Feifei Huang
Summary: This study focuses on the Chang-7 shale in the Ordos Basin and aims to understand the distribution characteristics and migration ability of gas components. The research confirms that shale gas in different locations has unique gas components due to gas migration.
Article
Geosciences, Multidisciplinary
Haikuan Nie, Chuanxiang Sun, Pei Li, Zhijun Jin, Quanyou Liu, Hanyong Bao, Baojian Shen, Wei Dang
Summary: A study on high-maturity shale from the Wufeng and Longmaxi Formations in the Sichuan Basin reveals the relationship between the degree of carbon isotope inversion and gas well production capacity (EUR), and indicates the preservation conditions of shale gas reservoirs. Carbon isotope inversion is a good indicator of shale gas preservation condition and EUR of shale gas wells.
GEOSCIENCE FRONTIERS
(2023)
Editorial Material
Environmental Sciences
Jasmin Cooper, Adam Hawkes
Summary: Phasing out carbon-intensive energy sources is crucial for meeting climate targets, but the role of natural gas is increasingly uncertain. All countries in the natural gas electricity value chain must make efforts to reduce emissions in order to achieve net-zero trajectory for natural gas electricity.
NATURE CLIMATE CHANGE
(2022)
Article
Energy & Fuels
Bo Zeng, Hui Li
Summary: This study constructs a dynamic adaptive four-parameter discrete grey forecasting model suitable for forecasting CBM production, which is then applied to simulate China's CBM ground production. The model achieves a comprehensive mean relative percentage error of 0.4765% and a grade I simulation accuracy, indicating superior performance compared to other mainstream grey forecasting models.
Article
Geochemistry & Geophysics
Yanhua Shuai, Yongqiang Xiong, Jian Li, Wei Wu, Guoyi Hu
Summary: Abiotically synthesized hydrocarbons have significant implications in various fields, but identifying them in common sediments is challenging. This study found distinct isotopic depletion in the central carbon of propane, indicating the occurrence of surface catalyzed polymerization reactions of methane in commercial gas reservoirs.
ORGANIC GEOCHEMISTRY
(2023)
Article
Geosciences, Multidisciplinary
Yongbo Wei, Shuangfang Lu, Junqian Li, Rongze Yu, Wenbiao Li, Feng Cheng, Chunbo Fu, Tianlong Zhao, Wenjun Feng, Zhaojing Song
Summary: The study investigates methane carbon isotope fractionation during shale gas desorption, revealing the impact of various factors on the process and providing insights into evaluating gas content and production status in shale gas wells.
MARINE AND PETROLEUM GEOLOGY
(2021)
Article
Geochemistry & Geophysics
Zhen-Min Ge, Xiao-Long Huang, Wei Xie, Tobias W. Hofig, Fan Yang, Yang Yu, S. Khogenkumar Singh
Summary: The mantle source composition of the nascent oceanic crust in the central part of the Gulf of California has been investigated using basaltic glass samples. These samples show trace element patterns similar to enriched mid-ocean ridge basalts, suggesting that the nascent oceanic crust in the Guaymas Basin might be generated through partial melting of a depleted mantle source metasomatized by subducted slab materials.
Article
Geochemistry & Geophysics
Jean-Michel Brazier, Katja E. Goetschl, Martin Dietzel, Vasileios Mavromatis
Summary: This study estimated the distribution coefficient of Zn2+ between calcite/aragonite and reactive fluids and found that the growth rate strongly influences D-Zn(2+) in both minerals. Additionally, a linear correlation was found between D-Zn(2+) and the saturation degree of the reactive fluid.
Article
Geochemistry & Geophysics
Ming Lei, Michele Lustrino, Jifeng Xu, Zhiqiang Kang, Zhengfu Guo, Jianlin Chen
Summary: This study presents a comprehensive geochronological, mineralogical, and geochemical analysis of olivine leucitites in the Maiga area of southern Tibet, suggesting that these rocks originate from a carbonated peridotite mantle source and highlighting the possibility of carbonates being recycled deep into the mantle during continental subduction.
Article
Geochemistry & Geophysics
Yuntao Ye, Xiaomei Wang, Huajian Wang, Haifeng Fan, Zhigang Chen, Qingjun Guo, Ziteng Wang, Chaodong Wu, Donald E. Canfield, Shuichang Zhang
Summary: Phosphorus is an essential element for life and its cycle in the ocean is closely connected with the carbon and oxygen cycles. The study of phosphate oxygen isotopes can provide insights into various reactions related to phosphorus. By analyzing carbonate fluorapatite samples from the Mesoproterozoic Era in North China, it was found that the oxygen isotope values were lower compared to modern samples, indicating a warmer climate during that time period and a potential reason for the scarcity of phosphorite.
Article
Geochemistry & Geophysics
Vincent Busigny, Oanez Lebeau, Didier Jezeduel, Carine Chaduteau, Sean Crowe, Magali Ader
Summary: This study conducted high-precision Mo isotope research on hydrothermal metal sulfides from a porphyry copper deposit in Southwest China and found that different stages of mineralization have distinct Mo isotope compositions, providing valuable insights into the behavior of Mo isotopes in magmatic-hydrothermal systems.
Article
Geochemistry & Geophysics
Min Ji, Xiao-Ying Gao, Yong-Fei Zheng, Bing Gong
Summary: The study examines the anatectic mechanisms in the Himalayan orogen, finding that pressure and temperature control the reaction, while water content mainly affects the solid-phase composition. Dehydration and hydration melting likely occur at different depths in the crust. This research provides important insights into the melting processes in collisional orogens.
