Abstract:Objectives: The Upper Carboniferous Keluke Formation is an important target position of the Paleozoic stratum in the Qaidam Basin, developing several sets of clastic sandstone reservoirs. Aiming to discuss the petrophysical characteristics and the control factors, the current study focuses on clastic rocks’ vertical units and horizantal distribution of Keluke Formation. Methods:The following studies, including reservoirs’ lithology, physical property, pore throats’ characteristics, and pore types, are analyzed on the basis of investigation of outcrops, inspection data from conventional and casting thinsections, scanning electron microscopes, physical property testing and mercury pressure.Results: In this study, several sets of conglomerate and coarse sandstone formations are built in the delta front facies of 2nd Member Keluke formation(C2k2) and in the tidal flat with barrier beach facies of 3rd Member Keluke formation(C2k3), which developed abundant primary and secondary pores. The pore throats are centrally distributed and well sorted, with spacious pore throats’ tunnels. All these clastic rocks could be favorable clastic reservoirs. The compaction, recrystallization and cementation have caused damage to sandstone’s primary pore during the early stage of diagenesis in the Keluke Formation. Conclusions: However, latestage diagenetic process enhanced reservoir property by creating dissolving holes and crack—dissolving holes, which are the main reservoir property for hydrocarbon accumulation. This study provides theoretical support for potential hydrocarbon reservoir prediction in Upper Carboniferous Keluke Formation in eastern Qaidam Basin.