Occurrence Mechanism and Key Controlling Factors of Wufeng-Longmaxi Shale Gas, Eastern Sichuan Basin
Dai Fangyao
Hao Fang
Hu Haiyan
Lin Junfeng
Li Qi
Abstract：Shale gas is one important kind of natural resources, which occurs in reservoir by free state and absorbing state.In order to reveal its accumulation mechanism, it is significant to study and illuminate the TOC content, main controlling factors, evolution rule of shale gas.In this study, we analyze the main controlling factor of free gas and absorbed gas in reservoir comprehensively by high temperature and high pressure adsorption isothermal experiment, FE-SEM, CO2 adsorption experiment, N2 adsorption experiment and mercury injection experiment.The results show that free gas is controlled by pore types and pore structure of shale, temperature and pressure in reservoir;while absorbed gas is controlled by TOC, maturity and moisture.In different stages of hydrocarbon generation, the content of free gas and absorbed gas changes regularly.Free gas occurs in the highly mature stage, and increases the process of hydrocarbon generation and the evolution of pores.It transforms into absorbed gas in the lifting stage because of the changes of temperature and pressure, which results in free gas decrease and absorbed gas increase.
Keywords：shale gasfree gasadsorbed gasJiaoshiba areaWufeng Formation-Longmaxi Formationpetroleum geology.
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( 1185-1194 )