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.