GENESIS OF LOW-PERMEABILITY TIGHT JURASSIC SANDSTONE RESERVOIRS AND POTENTIAL OF DEVELOPING GOOD-QUALITY RESERVOIRS IN HEFEI BASIN

Jurassic reservoir sand body was widely developed in Hefei Basin, But the porosity and permeability and pore structure of sandstone are all worse.The analysis on available samples reveals that the sand body mainly belongs to low-permeability tight reservoirs, and only the Upper Jurassic has moderate storage quality. In this paper,the genesis of tight Jurassic sandstone reservoirs is discussed in detail by means of section observation, cathodoluminescence test, scaning electron microscope test etc. and comprehensive analyses and investigations. Four types of reservoirs are classified based on their origin. Reservoir potential is varied with different reservoir types. Combined with Organic Geochemistry,Seismic Stratigraphy and so on,the conclusion that the Jurassic strata in Hefei Basin have the potential of developing good-quality sandstone reservoirs is obtained. The directiOn of developing good-quality reservoirs is also pointed out.