关键词: 塔里木盆地, 志留系, 沥青砂岩, 储层物性, 孔隙结构, 表征方法

Abstract: The Silurian bitumen sandstone in Tarim Basin is spread in the bulk-like,layer-like and heterogeneous spot-like styles in macroscopic scale,while different types of bitumen are filled in the pores and cementations with the filling-type and surrounding-type in microscopic scale.The experimental results show that the traditional analysis on physical properties of sandstone cannot describe the reservoir characteristics and porous structures of different sandstones filled with different types of bitumen.The quantitative measurements were made,and a new method for describing the reservoir characteristics by the use of residual porosity and resdidual permeability was proposed.The further experiment shows that the low-viscosity oil can fill the bitumen sandstone with the residual porosity higher than 4% and dissolve the organic matters,which greatly increase the residual porosity and residual permeability of bitumen sandstone.This kind of sandstone becomes the effective reservoir.

Key words: Tarim Basin, Silurian, bitumen sandstone, reservoir characteristics, porous structure, characterization method