双河油田聚合物驱后储层参数变化规律

油田经历聚合物驱开发后,储层物性参数发生改变,对油田后期开发有重要的影响。文中利用双河油田取心井室内化验分析资料,研究了聚合物驱后储层孔隙度、渗透率以及孔隙结构变化特征,探讨了储层参数变化机理。研究结果表明:聚合物驱后由于聚合物分子在地层的吸附滞留作用,造成储层渗透率下降,后续水驱阶段渗透率有一定恢复;聚合物驱后储层非均质性进一步加剧,物性和孔隙结构好的储层孔隙度和渗透率增大,而物性差的储层渗透率下降,孔喉半径减小,部分发生了堵塞现象。黏土矿物迁徙、运移,以及岩石骨架溶蚀、碎裂、运移是聚合物驱后储层参数发生变化的主要原因。

Variation of reservoir parameters after polymer flooding in Shuanghe Oilfield

After the oilfield has undergone polymer flooding development,the physical parameters of the reservoir have changed,and changes in the reservoir parameters have an important impact on the later development of the oilfield.Using laboratory analysis data of coring wells in Shuanghe Oilfield,the characteristics of porosity permeability and pore structure of the reservoir after polymer flooding were studied,and the mechanism of change of reservoir parameters was discussed.The results show that after polymer flooding,the permeability of the reservoir decreases due to the adsorption and retention of polymer molecules in the formation,and has a certain recovery in the subsequent flooding stage.After polymer flooding,reservoir heterogeneity is further aggravated,reservoirs with good physical properties and good pore throat structures have larger pores and percolations,while reservoirs with poor physical properties have reduced permeability,reduced pore throat radius,and partially blocked.Clay minerals are scoured,migrated,and rock skeletons are disintegrated and fragmented,that were the main reasons for changes in reservoir parameters after polymer flooding.