Geochemical characteristics and source analysis of natural gas in the saline lacustrine basin in the Western Qaidam basin
Title
Geochemical characteristics and source analysis of natural gas in the saline lacustrine basin in the Western Qaidam basin
Subject
Natural gas
Carbon isotope
Gas-source correlation
Genesis
Qaidam basin
Description
Abstract: This paper analyzed the geochemical characteristics and the sources of natural gas in the western Qaidam Basin based on isotopes and gas composition. The natural gas in the western Qaidam Basin is mainly comprised of hydrocarbon gases, including sapropelic, humic and mixed gas. In the southwestern Qaidam Basin, the main gas is sapropel gas, with some mixed gas and a small amount of humic gas. In contrast, the northwestern Qaidam Basin contains mainly humic gas, some mixed gas, and a small amount of sapropel gas. The dryness coefficient varies between 0.6 and 0.95. The carbon isotopes of methane, ethane, and propane are distributed between −32.9‰ ~ −51.4‰, −34.2‰ ~ −22.4‰, −30‰ ~ −17.4‰, respectively. The calculated Ro value of the natural gas is between 0.5% and 1.87%. In general, the natural gas shows the characteristics of high dryness coefficient, heavy carbon isotopes, and high thermal maturity. The gas-source correlation makes it clear that the main hydrocarbon source rocks in the western Qaidam Basin are the lower Ganchaigou (E3), the upper Ganchaigou (N1) and the lower Youshashan formations (N21). The gas-producing layers in the northwestern Qaidam Basin are primarily from the lower Ganchaigou (E3), the lower Youshashan (N21), and the upper Youshashan formations (N22). The primary gas source rocks are the lower Ganchaigou (E3), the upper Ganchaigou (N1), and the lower Youshashan formations (N21). The main gas-producing layers in the southwestern Qaidam Basin are the lower Ganchaigou (E3), the upper Ganchaigou (N1), the lower Youshashan (N21) and the upper Youshashan formations (N22), with the main gas source rocks being the lower Ganchaigou Formation (E3).
Publisher
Journal of Petroleum Science and Engineering
Date
2021-01-16
Contributor
Jian, Li
Jixian, Tian
Chenglin, Liu
Dehao, Feng
Xu, Zeng
Mai, Zhang
Zeqing, Guo
Hua, Kong
Awan, Rizwan Sarwar
Zhijie, Li
Sai, Yang
Type
journalArticle
Identifier
5BNR5IB3
0920-4105
10.1016/j.petrol.2021.108363
Collection
Citation
“Geochemical characteristics and source analysis of natural gas in the saline lacustrine basin in the Western Qaidam basin,” Lamar University Midstream Center Research, accessed May 4, 2024, https://lumc.omeka.net/items/show/2214.