Rock vibration and finite oil recovery

Abstract

Basic information concerning the possibility of mechanical stimulation of an oil reservoir is presented. The positive effect of vibration on the oil fraction in the output of flooded wells is demonstrated. The effect is attributed to the restoration of permeability for dispersed oil as a result of drop clusterization or breakdown. A mathematical model illustrating the special role of dominant vibration frequencies is proposed. This model is based on the nonlinear effects associated with internal viscoelastic resonance. The corresponding evolution equation of the seismic waves emitted by the vibrator is a generalization of the Burgers-Korteweg-de Vries equation. For this equation the existence of an asymptotic regular wave structure is proved. Taking the microparticle rotation effect into account leads to bimodal wave vibrations, and under conditions of long-short-wave resonance the nonlinear generation of high ultrasonic frequencies by seismic waves is possible. The ultrasonic vibrations created enable the oil drops to recover their mobility.