The imbibition of fracturing fluid can alter the original gas-water occurrence in reservoirs,thereby affect-ing the production behavior of shale gas wells.However,through dynamic displacement and nuclear magnetic reso-nance experiments,combined with previous research results,we analysis of the original gas-water distribution in pores,the effects of fracturing fluid imbibition on gas occurrence in through-pores and blind-pores,and the rela-tionship between gas well production behavior and fracturing fluid imbibition were carried out.The study reveals that the occurrence of original gas and water in pores is related to mineral types,fracture apertures,and reservoir humidi-ty.There is bound water in small pores and pore corners.The adsorption area of methane in large pores decreases with increasing reservoir humidity,and the amount of adsorbed gas is influenced by the proportion of organic matter pores and maturity.A zone affected by imbibition exists near fractures,where fracturing fluid imbibition can promote desorption of adsorbed gas,displace free gas in non-equilibrium imbibition through-pores,and compress free gas in equilibrium imbibition through-pores and blind-pores.The gas displaced from non-equilibrium imbibition through-pores is one of the main sources of free gas in hydraulic fractures.Only when the fracturing fluid retained in the wellbore,fracture and influence area is discharged,was gas be produced from various areas,resulting in the phenom-enon that the gas production curve lags behind the water production curve,and the fracture drainage resistance is much smaller than that of the matrix pore,which is the main reason for the"L"type decline of gas production and water production curve.The research findings focus on the impact of fracturing fluid imbibition on the occurrence and production of gas,contributing to the enrichment of shale gas reservoir protection theories.This has guiding sig-nificance for the efficient development of gas wells.
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