Numerical Study of Frequency-dependent Seismoelectric Coupling in Partially-saturated Porous Media

Abstract

Abstract. The seismoelectric phenomenon associated with propagation of seismic waves in fluid-saturated porous media has been studied for many decades. The method has a great potential to monitor subsurface fluid saturation changes associated with production of hydrocarbons. Frequency of the seismic source has a significant impact on measurement of the seismoelectric effects. In this paper, the effects of seismic wave frequency and water saturation on the seismoelectric response of a partially-saturated porous media is studied numerically. The conversion of seismic wave to electromagnetic wave was modelled by extending the theoretically developed seismoelectric coupling coefficient equation. We assumed constant values of pore radius and zeta-potential of 80 micrometers and 48 microvolts, respectively. Our calculations of the coupling coefficient were conducted at various water saturation values in the frequency range of 10 kHz to 150 kHz. The results show that the seismoelectric coupling is frequencydependent and decreases exponentially when frequency increases. Similar trend is seen when water saturation is varied at different frequencies. However, when water saturation is less than about 0.6, the effect of frequency is significant. On the other hand, when the water saturation is greater than 0.6, the coupling coefficient shows monotonous trend when water saturation is increased at constant frequency.

Thermo Electric Sensitivity Fractal Dimension for Characterizing Shajara Reservoirs of the Permo-Carboniferous Shajara Formation, Saudi Arabia

“…The amplitude of seismo electric signal increases with increasing permeability which means that the seismo electric effects are directly related to the permeability and can be used to study the permeability of the reservoir was illustrated by [10]. Seismo electric coupling is frequency dependent and decreases expontialy when frequency increases was demonstrated by [11]. An increase of permeability with increasing pressure head and bubble pressure fractal dimension was reported by [12,13].…”

On Similarity of Seismo Magentic Field and Pressure Head Fractal Dimension for Characterizing Shajara Reservoirs of the Permo-Carboniferous Shajara Formation, Saudi Arabia

“…The amplitude of seismo electric signal increases with increasing permeability which means that the seismo electric effects are directly related to the permeability and can be used to study the permeability of the reservoir was illustrated by [10]. Seismo electric coupling is frequency dependent and decreases expontialy when frequency increases was demonstrated by [11]. An increase of permeability with increasing seismo magnetic moment and seismo diffusion coefficient fractal dimension was reported by [12,13].…”

“…The Seismo magnetic field can be scaled as (1) Where Sw the water saturation, H the seismo magnetic field in ampere / meter, H max the maximum seismo magnetic field in ampere / meter, and Df the fractal dimension. Equation 1 can be proofed from 2Where H the seismo magnetic field in ampere / meter, SEC the seismo electric current in ampere, d the distance in meter The seismo electric current SEC can be scaled as 3Where SEC the seismo electric current in ampere, SEP the seismo electric potential in volt and R the resistance in ohm Insert equation 3 into equation 2 (4) The seismo electric potential SEP can be scaled as (5) Where SEP the seismo electric potential in volt, SEE the seismo electric energy in Joule, q the electric charge in coulomb Insert equation 5 into equation 4 (6) The seismo electric energy SEE can be scaled as (7) Where SEE the seismo electric energy in Joule, P the pressure in Pascal, and V the fluid volume in cubic meter Insert equation 7 into equation 6 (8) The Volume V can be scaled as (9) Where V the volume in cubic meter, Q the flow rate in cubic meter / second and t the time in second Insert equation 9 into equation 8 (10) The flow rate can be scaled as (11) Where Q the flow rate in cubic meter / second, r the pore radius in meter, ΔP the differentia pressure in Pascal, μ the fluid viscosity in Pascal * second, and L the capillary length in meter Insert equation 11 into equation 10 12The maximum pore radius r max can be scaled as…”

Seismic Shear Wave Velocity Fractal Dimension for Characterizing Shajara Reservoirs of the Permo-Carboniferous Shajara Formation, Saudi Arabia

“…The amplitude of seismo electric signal increases with increasing permeability which means that the seismo electric effects are directly related to the permeability and can be used to study the permeability of the reservoir was illustrated by Ping R [10]. Seismo electric coupling is frequency dependent and decreases expontialy when frequency increases was demonstrated by Djuraev U [11]. An increase of permeability with increasing pressure head and bubble pressure fractal dimension was reported by Alkhidir KEME [12,13].…”