塔里木盆地志留系沥青砂岩储集性非常规评价

塔里木盆地志留系沥青砂岩在宏观上以块状、顺层状、不均匀斑块状分布;在微观上,不同性质的沥青以充填状、侵染状充填于孔隙及胶结物中.实验表明,常规物性分析不能客观地表征被不同性质沥青充填的砂岩的储层物性及孔隙结构,因此在定量测算的基础上,提出了用残余孔隙度和残余渗透率来客观表征沥青砂岩储层物性及孔隙结构的方法.进一步的实验研究表明,低粘度原油可以再次充注残余孔隙度大于4%的沥青砂岩并溶解其中的有机质,使其残余孔隙度和残余渗透率大幅度提高,从而成为有效储层.

Non-traditional method for evaluating physical property of Silurian bitumen sandstone reservoirs in Tarim Basin

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.