FLOW MODEL OF IONIC LIQUIDS IN POROUS MEDIA UNDER COUPLED ELECTROMAGNETIC AND SEEPAGE FIELDS

Ionic liquids (ILs), as a class of green and environment-friendly materials, are adjustable and multifunctional. ILs have excellent electromagnetic field response, which hold a great promise for the adjustment of waterflooding pathway. In this paper, the electromagnetic response mechanism of ILs in capillary is firstly analyzed. Then a flow model of ILs in porous media under coupled electromagnetic and seepage fields is established. Finally, the theoretical derivation and numerical analysis results show that the capillary flow rate under coupled electromagnetic and seepage fields is mainly determined by the ratio of ILs conductivity to viscosity (internal factor), electromagnetic field strength and pressure gradient (external factors). The electromagnetic field generates an electromagnetic drive pressure on the ILs by Lorentz force, forming an electromagnetic drive equivalent pressure gradient analogous to the pressure gradient, thereby changing the flow rate of ILs. When the electromagnetic field strength is 2.0 × 104 V/m·T, the electromagnetic field can form a 10 kPa/m electromagnetic drive equivalent pressure gradient on an ILs with a conductivity of 0.5 S/m. Meantime, the flow direction of ILs in porous media can be controlled by adjusting the direction of electromagnetic field, which can solve the difficult problem of using pressure difference to control flow paths, and provides a theoretical basis for intelligent oil displacement of ILs. Furthermore, the thermal effect generated by the electromagnetic field will affect the flowing capacity of ILs and the oil displacement efficiency.