Characteristics and main controlling factors of tight sandstone reservoirs in Silurian of Kongquehe slope, Tarim Basin

The sandstone reservoir characteristics such as clastic component, sedimentation, diagenesis and so on in the Silurian of Kongquehe slope were analyzed based on the data of core, casting film, electron microscope scanning and reservoir property analysis to determine the main controlling factors of reservoir quality. The research result shows that reservoir lithology is mainly lithic sandstone and feldspathic litharenite, which have medium texture maturity and lower maturity composition. Reservoir accumulation properties are worse, which belong to low-porosity and extra-low-permeability tight sandstone reservoirs. Main reservoir space is corrosion pore between grains or in grains and a few micro-fractures. The connectivity between pore space and throat is poor. Sedimentation is the fundamental factor for the development of sandstone reservoirs in Silurian. Strong compaction and widespread cementation are the dominant factors. Structure fracturing and dissolution are also important factors for the formation of secondary pores in sandstone reservoirs.