准噶尔盆地阜东斜坡侏罗系砂岩成岩作用、孔隙演化及次生孔隙预测

DIAGENESIS, POROSITY EVOLUTION AND SECONDARY POROSITY PREDICTION OF JURASSIC SANDSTONE RESERVOIR IN FUDONG SLOPE, JUNGAR BASIN

准噶尔盆地阜东斜坡区侏罗系砂岩储层为河流环境下形成的各类细粒岩屑砂岩.岩石主要经历了压实、胶结、溶蚀和晚期自生高岭石充填等成岩作用.孔隙类型主要为长石、岩屑及碳酸盐胶结物溶蚀形成的次生孔隙;溶蚀作用发生于晚成岩"A"期的中期,对应的地质年代为晚第三纪早期.次生孔隙在现今埋深为2000～2800m的河道砂岩中最发育,其形成主要受成岩演化阶段控制,其次受沉积微相控制.

The Jurassic sandstone reservoirs in Fudong Slope, Jungar Basin, are various fine_graded lithic sandstones deposited in a fluvial environment. These sandstones have experienced mechanical compaction, various cementations, dissolutions and late authigenic kaolinite filling. Most of pores are secondary ones which mainly generated from dissolution of feldspars, lithoclasts and carbonate cements. Their dissolution took place in the middle stage of late diagenesis 'A', which corresponds to early Neogene. This secondary porosity mostly developed in the fluvial channel sand_bodies buried between 2000～2800m currently, and its distribution may be controlled mainly by diagenesis and then by microfacies.