Seismic stimulation for enhanced oil recovery

Abstract

The pore-scale effects of seismic stimulation on two-phase flow are modeled numerically in random 2D grain0pack geometries. Seismic stimulation aims to enhance oil production by sending seismic waves across a reservoir to liberate immobile patches of oil. For seismic amplitudes above a welldefined ͑analytically expressed͒ dimensionless criterion, the force perturbation associated with the waves indeed can liberate oil trapped on capillary barriers and get it flowing again under the background pressure gradient. Subsequent coalescence of the freed oil droplets acts to enhance oil movement further because longer bubbles overcome capillary barriers more efficiently than shorter bubbles do. Poroelasticity theory defines the effective force that a seismic wave adds to the background fluid-pressure gradient. The lattice-Boltzmann model in two dimensions is used to perform pore-scale numerical simulations. Dimensionless numbers ͑groups of material and force parameters͒ involved in seismic stimulation are defined carefully so that numerical simulations can be applied to field-scale conditions. Using the analytical criteria defined in the paper, there is a significant range of reservoir conditions over which seismic stimulation can be expected to enhance oil production.

Viscosity effects in vibratory mobilization of residual oil

“…However, theory and numerical simulations elucidating the underlying physics responsible for the mobilizing effect of vibrations on residual hydrocarbons were not developed until the last decade ͑Graham and Higdon, 2000; Hilpert et al, 2000;Iassonov and Beresnev, 2003;Beresnev et al, 2005;Li et al, 2005;Beresnev, 2006;Iassonov and Beresnev, 2008;Pride et al, 2008͒. Considering that one of the fundamental reasons for unrecoverable oil is the entrapment of isolated blobs in pore constrictions by capillary forces, the theoretical studies have exposed the pore-scale mechanism of vibration-induced inertial forcing pushing the stuck ganglia over their capillary barriers. We define the capillary barrier here as a resistive force that a ganglion needs to overcome to pass through a constricted opening in a porous channel.…”

A framework for assessing the uncertainty in wave energy delivery to targeted subsurface formations

“…1(a)) can be used as a primary or secondary recourse for enhanced oil recovery, removal of trapped contaminant particles from aquifers, subsurface colloidal transport of contaminants at waste disposal sites, etc. (Beresnev and Johnson, 1994;Kouznetsov et al, 1998;Roberts et al, 2001;Kostrov and Wooden, 2002;Vogler and Chrysikopoulos, 2002;Iassonov and Beresnev, 2003;Pride et al, 2008;Roberts and Abdel-Fattah, 2009;Beresnev and Deng, 2010;Beresnev et al, 2011;Manga et al, 2012;Lo et al, 2012;Deng and Cardenas, 2013). The utility of the stimulation depends upon, among other factors, the magnitude of the wave motion generated in the target zone.…”

Effects of Pressure Oscillations on Drainage in an Elastic Porous Medium

“…The research has been developing in both experimental (Roberts et al 2001;Li et al 2005) and theoretical directions (Hilpert et al 2000;Iassonov and Beresnev 2003;Hilpert 2007;Pride et al 2008).…”

“…The S-wave corresponds to a shear (transverse) wave of the rock matrix. In a system with fluids and matrix of different densities, the S-wave generates body forces (Pride et al 2008). We focus on the compressional component of the seismic wave, the P-wave, and its effects on the soft inclusions in the system.…”