Frontal structure and stability in immiscible displacement

Conference · Sun Apr 01 04:00:00 EST 1984 · Soc. Pet. Eng. AIME, Pap.; (United States)

OSTI ID:6869656

Jerauld, G R; Davis, H T; Scriven, L E

A theory of the stability or instability of plane saturation fronts in immiscible displacements is presented which is more realistic than earlier theories. For given two-phase relative permeability functions, capillary pressure function, viscosity ratio, saturation ahead of the front, and allowable front-propagation speed, the displacement-front saturation profile of permanent form is calculated from Rizhik et al.'s (1961) solution by quadrature of the nonlinear convective diffusion equations for two-phase flow with significant capillary effect. Stability of the saturation profile of permanent form with respect to small disturbances in pressure and saturation (as may be caused by minor heterogeneities in a reservoir) is found by solving the generalized eigenproblem to which linear stability theory and finite differencing lead. The results show that when the front is unstable there is a fastest growing wavelength of disturbance transverse to the flow. Shorter wavelengths are slowed or stabilized by capillary-pressure-gradientdriven flow; longer wavelengths grow more slowly because the transverse pressure gradients driving them are weaker. If the displacing fluid is viscous enough the front is stable, but the larger the scale of disturbance the more nearly it is marginally stable. An earlier theory that approximates the front as a discontinuity agrees roughly but differs in important details, among them the mildly stabilizing effect associated with the saturation profile in the frontal zone.

• Research Organization: Univ. of Minnesota
• OSTI ID: 6869656
• Report Number(s): CONF-8304162-
• Conference Information: Journal Name: Soc. Pet. Eng. AIME, Pap.; (United States) Journal Volume: SPE/DOE 12691
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
CAPILLARY FLOW
DISPLACEMENT FLUIDS
FLUID FLOW
FLUID INJECTION
FLUID MECHANICS
FLUIDS
HETEROGENEOUS EFFECTS
HYDRODYNAMICS
MECHANICS
MISCIBLE-PHASE DISPLACEMENT
OIL SATURATION
OIL WELLS
PHASE STABILITY
PHASE STUDIES
PRESSURE DEPENDENCE
PRESSURE GRADIENTS
RESERVOIR FLUIDS
RESERVOIR ROCK
SATURATION
STABILITY
VISCOSITY
WAVE PROPAGATION
WELLS