铁磁流体驱油试验

Laboratory investigation of ferrofluid flooding for oil recovery

铁磁流体作为一种可控的新型功能材料,当存在外磁场时将在铁磁流体中产生磁场力并影响其在多孔介质中的流动。通过试验手段首次研究铁磁流体驱油问题。首先,结合二维单相平板试验结果验证磁场力表达式及将磁场力作为一种彻体力的形式引入运动方程的正确性;其次,制作二维非均质及裂缝性填砂平板物理模型,在此基础上分别利用铁磁流体和水作为驱替液进行驱油试验,并对比两者驱油开发效果。结果表明:利用磁铁施加外磁场可以在铁磁流体中产生磁场力,磁场力可以控制铁磁流体在多孔介质中的流动,控制并改变铁磁流体驱替路径,克服由于非均质性等因素造成的驱替波及范围小、原油动用程度低的问题,扩大波及范围,提高采收率。

In recent years,controllable ferrofluid has attracted a lot of attention in oil industry as a new function material.In this study,laboratory experiments of ferrofluid flooding for oil recovery were conducted at the first time,in which the mobilization of the ferrofluid through porous media was achieved via applying strong external magnetic fields.In modeling,the magnetic force has been introduced into the Darcy equation and a finite element method was used for the solution of the model.The effectiveness of the magnetic flow model was demonstrated by matching single-phase flow experiments.Water flooding and ferrofluid flooding in heterogeneous and fractured porous media were conducted.The results show that the flow behavior of the ferrofluid in porous media can be controlled by applying external magnetic field,so that the scope of the whole displacement can be raised,which can lead to significantly improved oil recovery superior to conventional water flooding.