扶余油田注水开发过程中储层孔隙结构变化特征

Reservoir pore structure and evolution characteristics in the process of water injection development in Fuyu Oilfield

研究油田注水开发过程中储层孔隙结构及演化特征,对于制定剩余油开发方案意义重大。利用不同含水期密闭取心井的薄片、扫描电镜、压汞及物性等分析化验资料,在翔实分析储层孔隙结构特征的基础上,利用统计分析手段查明了该油田注水开发过程中储层孔隙结构演化特征。研究结果表明,扶余油田储层孔隙类型主要为粒间孔与粒间溶孔,胶结物主要为泥质;由于注入水的冲刷影响,致使孔隙中的粘土矿物分散及漂移,进而导致胶结类型由中低含水期孔隙-接触式转变为高含水期的孔隙式;注水开发对孔隙半径均值和中值的影响较小;最大、平均孔隙半径相同的情况下,渗透性随着水淹程度加大,渗透率增大,而孔隙半径中值、孔隙半径均值变化较小。

It is of great significance to make the remaining oil development plan that studies the pore structure and the evolution characteristics in the process of water injection development. Making use of testing data of thin section, scanning electron microscopy, mercury intrusion and physical property in dif- ferent water cut period of pressure coring well, the reservoir pore structure characteristics are analyzed in-depth and systematically, and the reservoir pore structure and evolution characteristics are found during the oilfield waterflood development using statistical analysis method. Research results show that the reservoir pore types in Fuyu oilfield are intergranular pore and intergranular dissolved pore, and cement is mainly argillaceous;Due to injection water scouring effect, it cause the clay content in pore to separate and drift, and result in cementation types translate pore-contact in the low and medium water cut period into pore type in high water cut period;In the process of water injection development, the influence of the water injection development on median and the mean radius is small, then on the other hand,the influence on the maximum pore and small pore is the bigger;For the same maximum and average pore radius, the permeability increases with the watered-out degree increasing, the changes of median pore radi- us and pore radius are small.