Shale gas content and geochemical characteristics of marine-continental transitional shale: A case from the Shanxi formation of Ordos basin
SUN Zepeng
WANG Yongli
WEI Zhifu
ZHANG Mingfeng
WANG Gen
WANG Zixiang
ZHUO Shengguang
XU Liang
Abstract：Lower Permian Shanxi formation marine-continental transitional shale is one of the most important shale gas exploration beds in Ordos basin.To investigate the shale gas content and its geochemical characteristics,two drilling core samples were selected for test including canister adsorption experiment,chemical components,carbon isotopic compositions and other geochemical analyses.The results show that the Shanxi formation shale has good geological conditions for shale gas generation.It is characterized by high organic content (TOC in the range of 1.73％-3.09％).The kerogen type is]Ⅲ,and is still in the evolution from maturity to over maturity.The volume fraction of methane contained in the desorbed gas ranges from 80.07％ to 96.29％,with an average of 88.79％.The carbon isotopic composition of methane and ethane varies from-49.2％ to-36.9％ and-17.1％ to-15.4％,respectively.The carbon isotope distribution pattern is positive (δ13 C1 ＜δ13 C2),indicating that the shale gas is thermogenic origin.The average content of the desorbed gas (0.38 m3/t) falls in the range of desorbed gas content of Wufeng-Longmaxi formation in Sichuan basin,which has already had the shale gas production capacity.It is demonstrated that the marine-continental transitional shale of Shanxi formation in Ordos basin has good potential for shale gas exploration.
Keywords：shale gasmarine-continental transitionalShanxi formationshale gas contentgenetic typesOrdos basin
Publication Date：2017-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：10( 859-868 )