An Improved Approach to Estimate Three-Phase Relative Permeability Functions for Heavy-Oil Displacement Involving Instability and Compositional Effects

Simultaneous three-phase flow of gas, oil and water is a common phenomenon in enhanced oil recovery techniques such as water-alternating-gas (WAG) injection. Reliable reservoir simulations are required to predict the performance of these injections before field application. However, heavy oil displacement by gas or water can lead to viscous fingering due to the unfavorable mobility ratio between heavy oil and the displacing fluid. In addition, the injection of partially dissolvable gases such as CO2 can result in compositional effects, which can bring about a significant reduction of oil viscosity and hence can cause variations of the mobility ratio. Estimations of three-phase relative permeability under such conditions are extremely complex, and using conventional techniques for the estimation can lead to erroneous results. We used the results of four coreflood experiments, carried out on a core, to estimate two-phase and three-phase relative permeability. A new history matching methodology for laboratory experiments was used that takes into account the instability and the compositional effects in the estimation processes. The results demonstrate that a simultaneous CO2 and water injection (CO2-simultaneous water and gas (SWAG)) can be adequately matched using the relative permeabilities of a secondary gas/liquid and a tertiary oil/water. In heavy oil WAG injection, the injected water follows the CO2 path due its lower resistance as a result of the CO2 dissolution in the oil and the resultant reduction of the oil viscosity. This is contrary to WAG injection in conventional oils, where gas and water open up separate saturations paths. It is also important to include capillary pressure (Pc), even in high permeable porous media, as we observed that the inclusion of capillary pressure dampened the propagation of the viscous fingers and hence helped the front to become stabilized, leading to a more realistic simulated sweep efficiency.

[1]  Francis M. Carlson,et al.  Simulation of Relative Permeability Hysteresis to the Nonwetting Phase , 1981 .

[2]  Apostolos Kantzas,et al.  Insights Into Non-Thermal Recovery of Heavy Oil , 2009 .

[3]  G. R. Jerauld,et al.  The effect of pore-structure on hysteresis in relative permeability and capillary pressure: Pore-level modeling , 1990 .

[4]  L. F. Koederitz,et al.  Relative Permeability Of Petroleum Reservoirs , 1986 .

[5]  H. J. Welge.  Displacement of Oil from Porous Media by Water or Gas , 1949 .

[6]  U. G. Araktingi,et al.  Viscous Fingering in Heterogeneous Porous Media , 1993 .

[7]  Martin J. Blunt.  An Empirical Model for Three-Phase Relative Permeability , 2000 .

[8]  H. L. Stone.  Probability Model for Estimating Three-Phase Relative Permeability , 1970 .

[9]  L. Scriven,et al.  Frontal Structure and Stability in Immiscible Displacement , 1984 .

[10]  J. Sherwood.  Unstable fronts in a porous medium , 1987 .

[11]  A. S. Emanuel,et al.  A Laboratory Study of Heavy Oil Recovery With CO2 Injection , 1983 .

[12]  Guy Chavent,et al.  Simultaneous estimation of relative permeabilities and capillary pressure , 1992 .

[13]  S. C. Jones,et al.  Graphical Techniques for Determining Relative Permeability From Displacement Experiments , 1978 .

[14]  R. A. Morse,et al.  Simultaneous determination of capillary pressure and relative permeability by automatic history matching , 1988 .

[15]  F. J. Fayers,et al.  Extensions to Dietz theory and behavior of gravity tongues in slightly tilted reservoirs , 1990 .

[16]  Mahmoud Jamiolahmady,et al.  Mechanistic Study of Improved Heavy Oil Recovery by CO2-Foam Injection , 2011 .

[17]  T. Babadagli,et al.  Investigating Uncertainties in Relative Permeability Measurements , 2005 .

[18]  H. D. Outmans.  Nonlinear Theory for Frontal Stability and Viscous Fingering in Porous Media , 1962 .

[19]  Adrian D. Jones,et al.  Comparison between Laboratory Experiments and Detailed Simulations of Unstable Miscible Displacement Influenced by Gravity , 1990 .

[20]  E. F. Johnson,et al.  Calculation of Relative Permeability from Displacement Experiments , 1959 .

[21]  Venkateswaran Sriram Pudugramam,et al.  Novel Three-Phase Compositional Relative Permeability and Three-Phase Hysteresis Models , 2015 .

[22]  Hamdi A. Tchelepi,et al.  Linear stability analysis of immiscible two-phase flow in porous media with capillary dispersion and density variation , 2004 .

[23]  Guy Chavent,et al.  Multiscale Representation for Simultaneous Estimation of Relative Permeabilities and Capillary Pressure , 1990 .

[24]  E. M. Braun,et al.  Relative permeability hysteresis: Laboratory measurements and a conceptual model , 1995 .

[25]  G. Jerauld.  General Three-Phase Relative Permeability Model for Prudhoe Bay , 1997 .

[26]  F. M. Garcia.  A Successful Gas-Injection Project in a Heavy Oil Reservoir , 1983 .

[27]  L. Baker.  Three-Phase Relative Permeability Correlations , 1988 .

[28]  Carlon S. Land,et al.  Calculation of Imbibition Relative Permeability for Two- and Three-Phase Flow From Rock Properties , 1968 .

[29]  Jyotsna Sharma,et al.  Experiments and Analysis of Multiscale Viscous Fingering During Forced Imbibition , 2012 .

[30]  Ruben Juanes,et al.  A New Model of Trapping and Relative Permeability Hysteresis for All Wettability Characteristics , 2008 .

[31]  Arne Skauge,et al.  Methodology for Numerical Simulation With Cycle-Dependent Relative Permeabilities , 1998 .

[32]  M. Sohrabi,et al.  An improved approach for estimation of flow and hysteresis parameters applicable to WAG experiments , 2016 .

[33]  R. B. Lantz.  Quantitative Evaluation of Numerical Diffusion (Truncation Error) , 1971 .

[34]  S. A. Farzaneh,et al.  A New Methodology for Improved Estimation of Two-Phase Relative Permeability Functions for Heavy Oil Displacement Involving Compositional Effects and Instability , 2016 .

[35]  M. C. Leverett,et al.  Capillary Behavior in Porous Solids , 1941 .

[36]  W. H. Thomas,et al.  A NEW VERSATILE RELATIVE PERMEABILITY CORRELATION , 2005 .

[37]  Emil O. Frind,et al.  An overview of immiscible fingering in porous media , 1988 .

[38]  G. Kissel,et al.  Viscous Fingering Effects in Solvent Displacement of Heavy Oil , 2004 .

[39]  Mahmoud Jamiolahmady,et al.  Reducing heavy oil carbon footprint and enhancing production through CO2 injection , 2011 .

[40]  D. L. Flock,et al.  The Onset of Instability During Two-Phase Immiscible Displacement in Porous Media , 1981 .

[41]  Sebastian Geiger,et al.  Three-Phase Pore-Network Modeling for Reservoirs With Arbitrary Wettability , 2013 .

[42]  H. L. Stone.  Estimation of Three-Phase Relative Permeability And Residual Oil Data , 1973 .

[43]  Chengyao Song,et al.  Simultaneous Estimation of Relative Permeability and Capillary Pressure for Tight Formations from Displacement Experiments , 2012 .