裂缝性油藏弹性储容比和窜流系数变化规律研究

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

测量了基质和裂缝性岩心孔隙度和渗透率的应力敏感性,裂缝性岩心的渗透率和孔隙度应力敏感程度比基质岩心强得多,随着渗透率的增加,基质岩心的应力敏感性减弱;推导了地层压力下降过程中弹性储容比和窜流系数协同变化关系,二者在半对数坐标系中呈现明显的线性关系,随着弹性储容比的增加,窜流系数呈现减小的趋势;研究了考虑应力敏感的裂缝性油藏弹性储容比和窜流系数变化对压力及压力导数的影响,结果表明:弹性储容比和窜流系数变化影响窜流出现的时间和窜流量的大小。

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.