By using sedimentary facies analysis method that unifies macroscopic geologic knowledge and microcopic geologic evidences

we conduct the analysis

interpretation and correlation of logging data and observation of cores more than 400 wells.It is thought that the sedimentary facies of the Paleozoic Taiyuan Formation in the Daniudi gas field is debris coastalcarbonate platform and delta in a regional epicontinental sea setting where delta distributary channel and tidal sand bar are deposited.The sedimentary facies of the 1

st

 member of the Lower Shihezi Formation is lakebraided river delta in a paleostructuresedimentary background with high relief where distributary channel and interchannel microfacies are developed.These sedimentary facies and sand distribution features determine the worsening of reservoir quality and productivity of sandbodies in the 2

nd

 member of the Taiyuan Formation from northeast to southwest.The plays with high production potential mainly occur in the northcentral part of NNEtrending sandbody in the study area.The chance is bad for them to occur in the 1

st

 member of the Shihezi Formation in the study area.Plays with moderate production potential distribute in the northcentral part of the study area.