羌塘盆地侏罗系碳酸盐岩储集层特征

在野外露头资料研究的基础上,运用岩石薄片、铸体薄片、扫描电镜、常规物性、毛细管压力曲线等手段,对羌塘盆地侏罗系碳酸盐岩储集层的岩石学、孔渗性及孔隙结构等特征作了详细研究。岩石类型主要为颗粒灰岩,包括内碎屑灰岩、鲕粒灰岩和生屑灰岩。储集空间包括孔隙和裂缝两种,孔隙主要为次生溶孔,裂缝为构造缝和溶蚀缝。孔隙的微观结构较差,基本上属于低孔低渗致密储集层。强烈的机械压实作用、胶结作用是导致储集层孔隙结构变差的主要因素,后期的溶解作用对储集层物性有一定的改善。构造作用使得岩石中裂隙发育,提高了岩石孔渗性,极大地改善了岩石的储集性能。

The Carbonate Reservoir Rocks of Jurassic in Qiangtang Basin

Based on the outcrop data, using such analytical techniques as rock thin section, cast section, SEM, conventional petrophysical property and capillary pressure curve, etc., the detailed studies are made in lithology, porosity-permeability distribution and pore structure. The carbonate reservoir rocks are dominated by granule limestone, including intraclast limestone, oolith limestone and bioclast limestone. The type of reservoir space includes pore (secondary solution pore) and fracture/fissure (structural fracture and solution fissure), with poor microstructure, belonging to a dense reservoir with low porosity and low permeability. The main factors are strong compaction and cementation. The late solution acted as a certain improvement on the reservoir quality. The tectonic action creates the fractures or fissures, increases the porosity/permeability of carbonate rocks and greatly improves the reservoir capacity in Qiangtang basin.