Simplifying reservoir models by flow regime
Author(s)
Rashid, Bilal
Type
Thesis
Abstract
This study focuses on the interaction between geological heterogeneity and the reservoir
processes which govern fluid flow in porous media. We have developed and
tested a measure of heterogeneity which uses the coefficient of variation of the vorticity
of the flow field to quantify the impact of geological uncertainty on oil recovery.
We go on to explore the vorticity formulation of the equations of motion in porous
media as a basis for understanding reservoir dynamics, particularly in the presence of
heterogeneity and density differences. We derive dimensionless numbers to quantify
the relative importance of viscosity and density differences, molecular diffusion, dispersion,
and permeability heterogeneity on reservoir flow behaviour. This approach
is used to develop an objective measure of the impact of permeability heterogeneity
on reservoir performance, which we have compared with traditional heterogeneity
indices and shown how it may be used for realistic 2D and 3D geological models.
We have used our heterogeneity index, and the dimensionless numbers to analyse
the impact of heterogeneity, buoyancy effects, mobility ratio and dispersion on breakthrough
time and recovery for first contact miscible gas injection processes using
geologically realistic reservoir models. We find that the new heterogeneity number,
in conjunction with these dimensionless numbers, provides meaningful results for
real non-linear reservoir flows.
We present phase diagrams which show how reservoir performance depends on
mobility ratio, viscous-gravity ratio, and heterogeneity. We have proposed that the
phase diagram, and a comparison of these dimensionless numbers can be used to
identify the key factors which control recovery, thus assisting the engineer in determining
appropriate enhanced oil recovery (EOR) techniques, without resort to detailed
flow simulation. This will enable a quick, and more robust, evaluation of the
impact of geological uncertainty in the field.
processes which govern fluid flow in porous media. We have developed and
tested a measure of heterogeneity which uses the coefficient of variation of the vorticity
of the flow field to quantify the impact of geological uncertainty on oil recovery.
We go on to explore the vorticity formulation of the equations of motion in porous
media as a basis for understanding reservoir dynamics, particularly in the presence of
heterogeneity and density differences. We derive dimensionless numbers to quantify
the relative importance of viscosity and density differences, molecular diffusion, dispersion,
and permeability heterogeneity on reservoir flow behaviour. This approach
is used to develop an objective measure of the impact of permeability heterogeneity
on reservoir performance, which we have compared with traditional heterogeneity
indices and shown how it may be used for realistic 2D and 3D geological models.
We have used our heterogeneity index, and the dimensionless numbers to analyse
the impact of heterogeneity, buoyancy effects, mobility ratio and dispersion on breakthrough
time and recovery for first contact miscible gas injection processes using
geologically realistic reservoir models. We find that the new heterogeneity number,
in conjunction with these dimensionless numbers, provides meaningful results for
real non-linear reservoir flows.
We present phase diagrams which show how reservoir performance depends on
mobility ratio, viscous-gravity ratio, and heterogeneity. We have proposed that the
phase diagram, and a comparison of these dimensionless numbers can be used to
identify the key factors which control recovery, thus assisting the engineer in determining
appropriate enhanced oil recovery (EOR) techniques, without resort to detailed
flow simulation. This will enable a quick, and more robust, evaluation of the
impact of geological uncertainty in the field.
Date Issued
2013
Date Awarded
2013-03
Copyright Statement
Attribution NoDerivatives 4.0 International Licence (CC BY-ND)
Advisor
Muggeridge, Ann
Publisher Department
Earth Science and Engineering
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)