Analysis of Pore Structure and Water Permeation Property of a Shale Rock by Means of X-Ray CT

In this study, pore structures and water permeation property of a shale rock are analyzed by means of X-ray CT. The target samples are produced Kushiro district in Hokkaido, Japan. Underground of this area is consisted by Cretaceous formation. Firstly, one dimensional permeation tests were performed by using core sample retrieved from Cretaceous formation, and intrinsic permeability was evaluated. Secondly, the internal structure of rock samples was observed by X-ray CT scanner, and porosity distributions were also evaluated by comparing CT image data between the dry and the water-saturated conditions. It was found that Cretaceous formation has relatively low permeability as k=10-19 ∼ 10-18 m2. It was also found that the porosity of each sample was approximately 7%∼13%, however, porosity distribution was not uniform, and was strongly influenced by density distribution in samples.