Origin of Deep Oil and Gas Phase State Diversity and Evaluation of Secondary Geochemical Intensity:A Case Study of Marine Oil and Gas in Tarim Basin
Zhu Guangyou
Li Jingfei
Zhang Zhiyao
Abstract：The geochemical properties and phase types of marine oil and gas in Tarim basin are complex and diverse.Heavy oil,normal oil,condensate and natural gas coexist from a reservoir profile.By comprehensively applying various geochemical analysis methods,the information of phase types,components and stable isotopes of deep-seated Marine oil and gas in Tarim basin is obtained,and the geochemical characteristics of different phase types of oil and gas are compared,and demonstrate a variety of secondary geochemical mechanisms and processes such as biodegradation,gas invasion and fractionation,thermochemical sulfate reduction(TSR),and thermal cracking of marine oil and gas;And further the quantitative evaluation parameters formulae for the strength of secondary transformation based on the products of secondary geochemistry such as thiadiamondoids and ethanodiamondoids were established respectively,can be effectively used in the qualitative prediction of the spatial distribution of oil and gas properties and phase behavior,the diversity of deep oil and gas phase formation mechanism and distribution of prediction before drilling and has certain theory and guiding significance.
Keywords：biodegradationgas invasion fractionationTSR(sulfate thermochemical reduction)thermal crackingultra-deep oil reservoirTarim basinpetroleum geology
Publication Date：2025-06-30
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：16( 2163-2178 )