羌塘盆地侏罗系白云岩储层特征研究

羌塘盆地侏罗系白云岩分布广泛,其岩石类型可分为泥晶-微晶白云岩、残余颗粒白云岩和晶粒白云岩,前两者常与石膏相邻或伴生,后者与石膏无关.在沉积期后变化中经历了多种成岩作用改造,其中影响白云岩储集性的作用主要有溶蚀作用、重结晶作用和构造应力作用.本区白云岩主要储集空间为晶间孔、晶间溶孔和构造缝,细-粗晶白云岩储集物性好,为好-较好的储层.

RESERVOIR CHARACTERISTICS OF THE JURASSIC DOLOMITE IN THE QIANGTANG BASIN

The Jurassic dolomite is widely distributed in the Qiangtang Basin. It can be divided into dolomicrite, residual-grain dolomite and crystal grain dolomite three rock types. The former two are often adjacent or asso- ciated to gypsum, and the latter one has nothing to do with gypsum. In the postsedimentary changs, many kinds of diagenetic reconstruction have taken place, Among them, those which have some influences on the accumulation features of dolomite mainly include dissolution, recrystallization and tectonic stress processes. The major accumulation spaces of dolomite in the study area are intercrystal pores, intercrystal solution openings and tectonic fissures. Fine-coarse crystallized dolomite has good accumulation petrophysical properties, and is a kind of good-well reservoir.