Comparisons of Empirical Viscous-Fingering Models and Their Calibration for Heterogeneous Problems

Fayers, F.J.; Blunt, Martin J.; Christie,

doi:10.2118/22184-pa

Cited by 37 publications

(30 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The solid and dashed lines are the results of the 1-D analytical model and the 2-D numerical simulations, respectively. There is qualitative agreement between the two models as to the outer part of the solution, which is all that can be expected for a gravity unstable process [19]. The inner solution is shown in Fig.…”

Section: Resultssupporting

confidence: 67%

See 1 more Smart Citation

An empirical theory for gravitationally unstable flow in porous media

et al. 2013

View full text Add to dashboard Cite

In this paper, we follow a similar procedure as proposed by Koval (SPE J 3(2): [145][146][147][148][149][150][151][152][153][154] 1963) to analytically model CO 2 transfer between the overriding carbon dioxide layer and the brine layer below it. We show that a very thin diffusive layer on top separates the interface from a gravitationally unstable convective flow layer below it. Flow in the gravitationally unstable layer is described by the theory of Koval, a theory that is widely used and which describes miscible displacement as a pseudo two-phase flow problem. The pseudo two-phase flow problem provides the average concentration of CO 2 in the brine as a function of distance. We find that downstream of the diffusive layer, the solution of the convective part of the model, is a rarefaction solution that starts at the saturation corresponding to the highest value of the fractional-flow function. The model uses two free parameters, viz., a dilution factor and a gravity fingering index. A comparison of the Koval model with the horizontally averaged concentrations obtained from 2-D numerical simulations provides a correlation for the two parameters with the Rayleigh number. The obtained scaling relations can be used in numerical simulators to account for the density-driven natural convection, which cannot be currently captured because the grid cells are typically orders of magnitude

show abstract

Section: Resultssupporting

confidence: 67%

“…Fayers and Newley [18] and [17] introduced a three-parameter model to obtain a better description of viscous fingering with gravity effects. However, [19] pointed to the poor performance for gravity flow indicated, not only for Koval model itself but also for extensions like the [17,44] models.…”

Section: Introductionmentioning

confidence: 99%

An empirical theory for gravitationally unstable flow in porous media

et al. 2013

View full text Add to dashboard Cite

show abstract

“…15-16. An analogous formulation for the wateroil-solvent system was used by Blunt and Christie [6] and more recently by Juanes and Blunt [14] to derive an analytical solution for WAG injection, although in WAG injection the fingering takes place at the front between the solvent (gas) and the displaced oil. They found exact solutions by simultaneously solving the conservation Eqs.…”

Section: Analytical Solution With Fingeringmentioning

confidence: 99%

“…This has driven the development of empirical fingering models which capture the average behavior of a fingered front. These were originally derived for application in miscible gas injection ( [14,16,25]) but Bondor et al [7] proposed that the Todd and Longstaff model [25] could also be used to describe the fingering of water into the rear of a polymer slug. One drawback of these fingering models, however, is that the fitting parameters in their formulation may need to be calibrated by comparison with detailed simulation.…”

Section: Introductionmentioning

confidence: 99%

Analytical solution of polymer slug injection with viscous fingering

Hamid

Muggeridge

2018

Comput Geosci

View full text Add to dashboard Cite

We present an analytical solution to estimate the minimum polymer slug size needed to ensure that viscous fingering of chase water does not cause its breakdown during secondary oil recovery. Polymer flooding is typically used to improve oil recovery from more viscous oil reservoirs. The polymer is injected as a slug followed by chase water to reduce costs; however, the water is less viscous than the oil. This can result in miscible viscous fingering of the water into the polymer, breaking down the slug and reducing recovery. The solution assumes that the average effect of fingering can be represented by the empirical Todd and Longstaff model. The analytical calculation of minimum slug size is compared against numerical solutions using the Todd and Longstaff model as well as high resolution first contact miscible simulation of the fingering. The ability to rapidly determine the minimum polymer slug size is potentially very useful during enhanced oil recovery (EOR) screening studies.

show abstract

“…Microscopic displacement efficiency depends on pressure, 3,4 composition of the solvent and oil 5,6 and small (core) scale heterogeneity. 7,8 Sweep efficiency of a miscible flood depends on mobility ratio, [9][10][11][12] viscous-to-gravity ratio, [13][14][15] transverse Peclet number, 16 well configuration, and reservoir heterogeneity, [17][18] in general. The effect of reservoir heterogeneity is difficult to study at the laboratory-scale and is addressed mostly by simulation.…”

Section: Introductionmentioning

confidence: 99%

Improvement of Sweep Efficiency in Gasflooding

Mohanty¹

2008

View full text Add to dashboard Cite

Miscible and near-miscible gasflooding has proven to be one of the few cost effective enhance oil recovery techniques in the past twenty years. As the scope of gas flooding is being expanded to medium viscosity oils in shallow sands in Alaska and shallower reservoirs in the lower 48, there are questions about sweep efficiency in near- An equimolar mixture of NGL and lean gas is multicontact miscible with oil A at 1500 psi; ethane is a multicontact miscible solvent for oil B at pressures higher than 607 psi. WAG improves the microscopic displacement efficiency over continuous gas injection followed by waterflood in corefloods. WAG improves the oil recovery in the quarter 5-spot over the continuous gas injection followed by waterflood. As the WAG ratio increases from 1:2 to 2:1, the sweep efficiency in the 5-spot increases, from 39.6% to 65.9%. A decrease in the solvent amount lowers the oil recovery in WAG floods, but significantly higher amount of oil can be recovered with just 0.1 PV solvent injection over just waterflood. Use of a horizontal production well lowers the oil recovery over the vertical production well during WAG injection phase in this homogeneous 5-spot model. Estimated sweep efficiency decreases from 61.5% to 50.5%. In foam floods, as surfactant 4 to gas slug size ratio increases from 1:10 to 1:1, oil recovery increases. In continuous gasflood VAPEX processes, as the distance between the injection well and production well decreases, the oil recovery and rate decreases in continuous gasflood VAPEX processes. Gravity override is observed for gas injection simulations in vertical (X-Z) cross-sections and 3-D quarter five spot patterns. Breakthrough recovery efficiency increases with the viscous-to-gravity ratio in the range of 1-100. The speed up for the streamline calculations alone is almost linear with the number of processors. The overall speed up factor is sub-linear because of the overhead time spent on the finite-difference calculation, inter-processor communication, and non-uniform processor load. Field-scale pattern simulations showed that recovery from gas and WAG floods depends on the vertical position of high permeability regions and k v /k h ratio. As the location of high permeability region moves down and k v /k h ratio decreases, oil recovery increases. There is less gravity override. The recovery from the field model is lower than that from the lab 5-spot model, but the effect of WAG ratio is similar.5

show abstract

Comparisons of Empirical Viscous-Fingering Models and Their Calibration for Heterogeneous Problems

Cited by 37 publications

References 12 publications

An empirical theory for gravitationally unstable flow in porous media

An empirical theory for gravitationally unstable flow in porous media

Analytical solution of polymer slug injection with viscous fingering

Improvement of Sweep Efficiency in Gasflooding

Contact Info

Product

Resources

About