一类驱油剂在油藏孔隙中的流变与流动特性

化学驱中的驱油剂、原油及其混合物是一类在组成结构和性质上均十分复杂的流体,这些流体在油藏中的流变性和流动特性是影响驱油效率的主要因素。介绍了化学驱中几种复杂流体力学问题及其研究成果。就其流变性而言,聚合物溶液和碱-表面活性剂-聚合物(ASP)复合体系均属粘弹性流体,但在中等剪切速率的简单剪切流动条件下,其流变性可用幂律模式描述。在驱油过程中,驱油剂的稠度系数沿渗流方向呈指数规律减小,而幂指数则以线型规律递增。粘弹性流体在结构复杂的油藏孔隙中流动时,产生的二次流利于驱替孔隙盲端和喉道中的残余油。还探讨了化学

Rheological Property and Flow Behavior of a Kind of Oil Displacement Agent in Reservoir Pores

In chemical flooding, the fluids in reservoir such as oil displacement agent, oil and their mixture are complex fluids, their rheological and flow behavior strongly affect oil displacement efficiency. Several results on complex fluid mechanics in reservior pores are presented in the paper. The compound of Alkali Surfactant Polymer (ASP) is a kind of viscoelastic fluid, its rheological behavior can be formulated by power law model in simple shear flow within medium shear rate. In chemical flooding, consistency coefficient of the oil displacement agent declines exponentially, the power law exponent increases linearly in the direction of percolation flow. The vorticity may be relatively large when viscoelastic fluid flow in complex reservoir pores, this is favourable for displacement of residual oil in dead end and pore throat. The macro percolation character is also discussed.