On the Process of Gas Liberation in Porous Media

The aim of the present work is an experimental and computational analysis of the effect of gas liberation in a porous medium. The experiments are based on application of X-ray computed tomography (CT). A series of experiments on slow gas liberation was carried out. A mathematical model of the liberation process was developed based on the theory of differential depletion in the presence of a porous medium. The porous samples involved were low-permeable North Sea core plugs and artificial glass core. The results of the experiments indicate rather uniform gas production in different parts of the samples. The results of the calculations indicate noticeable, although not extreme, lowering of the bubble point pressure (0.12-0.18 MPa) and decreased production of gas, compared to the depletion carried out in a PVT cell.