水敏性低渗透储层油水两相渗透率JBN计算方法的改进

水敏性低渗透砂岩在水驱油过程中由于受到黏土膨胀、颗粒运移、堵塞等水敏影响,岩石的孔隙半径缩小、渗透率降低,出现注入压力异常的现象,采用常规的JBN方法计算油水两相渗透率会出现异常的相渗曲线。在考虑水敏性低渗透砂岩水驱油过程中水敏影响的基础上,对常规JBN解释方法进行了改进,以满足正确解释水敏性低渗透砂岩油水两相渗透率的需要,实例应用证实了改进方法的正确性与实用性。

Improve JBN Calculation Method of Oil and Water Two-phase Permeability of Water Sensitive Low-permeability Reservoirs

When the water sensitive low-permeability sandstone reservoir comes under the water-flooding process, abnormal injection pressure may appear owing to water sensitive influence, such as expansion of clay, migration of particles and plugging. Therefore, adoption of conventional JBN method to calculate oil and water two-phase permeability may lead to abnormal phase permeability curve. On the condition that water-sensitive influence is taken into account in the water-flooding process of watersensitive low-permeability sandstone reservoir, improvement is made on the conventional JBN interpretation method to meet the demand for correct interpretation of oil and gas water two-phase permeability of water-sensitive low-permeability sandstone reservoir. Actual application confirms correctness and feasibility of the improved method.