The volume and geochemical characteristics of desorption gases from Wufeng-Longmaxi (O3w-S1l) shale in the Xishui Area, North Guizhou, China
发布时间：2024-01-08
元数据
名 称
The volume and geochemical characteristics of desorption gases from Wufeng-Longmaxi (O3w-S1l) shale in the Xishui Area, North Guizhou, China
科技资源标识
CSTR:11738.14.NCDC.XDA14.PP4459.2024
DOI
10.3389/feart.2022.879959
数据共享方式
开放下载
摘 要
The Upper Ordovician–Lower Silurian Wufeng–Longmaxi (O3w-S1l) shale is widely distributed in the Xishui area, north Guizhou, China. However, the potential and characteristics of shale gases in the Xishui area are not well evaluated, which has limited the exploration of shale gas in this area. In this study, we collected 14 fresh core samples of Wufeng–Longmaxi Formations from Well XK-3 and conducted gas desorption experiments to evaluate the potential of shale gas resources in the Xishui area. After analyzing the chemical and isotopic composition of desorption gases, the origin and genesis of the shale gas were systematically studied. Our results show that the volume of desorption gases varies from 2.14 m3 /t to 6.01 m3 /t, with a mean value of 4.12 m3 /t, showing great potential for shale gas in this area. The positive correlation between total organic carbon (TOC) and desorption gas volume indicates that organic matter provides the main pore volume for shale gas preservation. The desorption gases are very dry, which are mainly composed of methane (99.64‰–99.74%) with a very low content of ethane, and no nitrogen, carbon dioxide, and hydrogen sulfide are detected. Based on geochemical diagrams, the desorption gases are identified as oil-associated thermogenic gases. The carbon isotopic values of methane and ethane display reversal distribution, due to the mixing of primary gases from kerogen cracking and the secondary gases from retained oil cracking and further possible cracking of heavy gaseous hydrocarbons (C3H8—C5H12) at higher thermal maturity (Ro > 2.00%). After comparing with Jiaoshiba, Changning, Weiyuan, and Dingshan areas, the carbon isotopic values of shale gases of Wufeng–Longmaxi shale also show different features at different areas, which are mainly controlled by the thermal maturity levels of the shale
Shuyong Shi. The volume and geochemical characteristics of desorption gases from Wufeng-Longmaxi (O3w-S1l) shale in the Xishui Area, North Guizhou, China. 国家冰川冻土沙漠科学数据中心(http://www.ncdc.ac.cn), 2024. https://cstr.cn/CSTR:11738.14.NCDC.XDA14.PP4459.2024.
Shuyong Shi. The volume and geochemical characteristics of desorption gases from Wufeng-Longmaxi (O3w-S1l) shale in the Xishui Area, North Guizhou, China. 国家冰川冻土沙漠科学数据中心(http://www.ncdc.ac.cn), 2024. https://www.doi.org/10.3389/feart.2022.879959.
本作品采用
知识共享署名
4.0 国际许可协议进行许可。
CSTR:11738.14.NCDC.XDA14.PP4459.2024
10.3389/feart.2022.879959