Abstract: The Jurassic formation in the area of Tai3—Bei 10 wells at cast Junggar fiasin is a reservoir of moderate storati- vity. The phenomena often occur such as poor permeablility , formation damage and serious sand production at the well bores during development. The radical reasons arc,besides abnormally high formation pressure,intertransformation of clay minerals and interstitial water release from smectite pressurization in the quartz—poor sandstone. Diagenesis of quartz—poor sandstone enlarges reduced primary pore volume. The degree of solution pore volume development is mainly a function of time and area of erosion and leach at(aiid near)the surface,with burial depth being the next important factor. Development zone of secondary pore is basically distributed in the channel sandstones under unconformily. Diagenesis has both favorable and unfavorable effects for quartz—poor sandstone of high clay mineral content.

Key words: Quartz-poor sandstone, Diagenesis, Reservoir characteristics