THE VARIATION LAW OF STORATIVITY RATIO AND INTERPOROSITY TRANSFER COEFFICIENT IN FRACTURED RESERVOIRS

The experiment on stress-dependent porosity and permeability of matrix cores and fractured cores shows that the stress sensitivity of the fractured cores is much stronger than that of the matrix cores. As the permeability increases, the stress sensitivity of the matrix cores decreases. The formulas of the synchronal alternation between the storativity ratio and the interporosity transfer coefficient during the reservoir pressure dropping have been derived, and the two factors are found to have a linear relationship in the semi-log coordinate, and the interporosity transfer coefficient declines with the storativity ratio increasing. The effect of synchronal variation between the storativity ratio and the interporosity transfer coefficient to the change of pressure and its derivative in the stress-sensitive and fractured reservoir has also been studied. The result shows that the variation of the storativity ratio and the interporosity transfer coefficient affects the crossflow occurring time and transfer rate of fluid from matrix to fracture.