Sulige gasfield in Ordos Basin is a typical tight gas reservoir.According to clastic constituents

diagenetic mineral assemblage

interstitial matter

and diagenesis types

et al

we identified 6 diagenetic faceis types in the 8th member of Xiashihezi Formation(He8)reservoir of Sulige gas field

including intergranular pore+strong solutional phase of volcanic material

intercrystal pore+solutional phase of volcanic material

intercrystal pore+solutional phase of debirs

intercrystal pore+cementation phase of quartz

hydromica cementation+weak solutional phase of debris and compaction+cementation tight phase.In addition

we analyzed the impacts of different digenesis on log responses.On the basis of these studies

a method for continuously and quantitatively identifying diagenetic facies was established by using gamma ray

interval transit time

density and deep lateral resistivity log data.Logging data of Well Z65 were processed with this method

and a comparison with the thin section data and mercury injection data show that the results are accurate.Based on single well diagenetic facies identification

we defined the diagenetic face distribution in He8 reservoirs of Sulige gasfield.The central part of the gas field is dominated by intergranular pore+strong solutional phase of volcanic material and intercrystal pore+solutional phase of volcanic material

which are the favorable diagenetic faces belts.