Experimental investigation of resonant frequency of sandstone saturated with magnetite nanofluid

Abstract

Electromagnetic wave is a viable means of introducing energy into reservoirs for the recovery of residual oil. However, previous studies have not considered the precise frequency of the electromagnetic (EM) wave. These studies focused on EM heating, not considering the efficiency dependence of EM transmitter and EM propagation on the EM properties of the medium. Thus, sandstone effective permittivity was experimentally measured, and electrical conductivity calculated for different saturation stages encountered in the nanofluid enhanced oil recovery process. The effective permittivity at the resonant frequency of the sandstone increased from 10.94 to 19.1 with a simultaneous frequency shift from 1.2 to 0.6 GHz due to the inclusion of magnetite nanofluid. This implies that the maximum transfer of EM energy for stimulation and activation of injected nanofluid can be achieved by irradiating the EM wave of this frequency within the reservoir for mobilization of the residual oil.

Unlocking Efficiency in Radio-Frequency Heating: Eigenfrequency Analysis for Resonance Identification and Propagation Enhancement in Nigerian Tar Sands

“…49 The EM response of the rock sample can be comprehensively explained using the Debye equation, a phenomenon supported by the observation of multiple relaxations within the measured frequency range. 50 This nuanced understanding of the interplay among EM waves, magnetic properties, and solvent injections not only expands our theoretical knowledge but also offers practical insights, potentially revolutionizing the way we approach EOR.…”