Abstract: The Su?5 block is located at the central part of the Sulige gasfield and characterized by high water cut and complicated gas?water relationship. Based on the existing geological and production performance data, this paper presents the correlation of reservoir features and studies the favorable prospecting area distribution. The results show that the lithology of reservoir is dominated by debris quartz sandstone with coarse grain and less difference of porosity; the difference of pore?throat texture determines the size of reservoir permeability, and influences the oil?bearing property of the reservoir; the main factors influencing the pore?throat texture are the secondary pores formed by dissolution in diagenesis and the intergranular micro?fissures formed by rupturing; the organic acidic liquid generated by diagenesis of the lower source rocks into the upper reservoir is the main reason for the dissolution; the high quality reservoir mainly distributed in He?8 member,could be the favorable target for ol?gas exploration in this area