Upscaling of Foam Mobility Control to Three Dimensions

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Upscaling of Foam Mobility Control to Three
Dimensions

• Busheng Li
• George Hirasaki
• Clarence Miller
• Rice University, Houston, TX

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Foam in Porous Media

• Foam in Porous Media
• Dispersion of gas in liquid
• liquid phase is continuous
• gas phase is discontinuous
• Stabilized from coalescence by the presence of
  surfactants

• Effects of Foam on Gas Flow
• Trapped foam reduces gas permeability
• Flowing bubble-trains increase effective gas
  viscosity

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Application of Foam on Gas Sparging
Without foam, gravity force dominates the gas
flow and gas sweep is poor
Foam can be used to control gas mobility and
increase gas sweep efficiency

• Problem
• Foam mobility is larger in 3-D than in 1-D
  Results from laboratory 1-D column experiments
  cannot represent foam behavior in 3-D
• Previous foam simulators which based on 1-D
  results cannot be used to design a 3-D field
  application

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Objectives

• Study 3-D foam behavior
• Build a simulation model to simulate 1-D and 3-D
  foam flow

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Layout of the 3-D Tank
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Experimental Description
Surfactant 0.05CS3300.05C13-4PO
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Foam Increases Gas Sweep Efficiency and Gas
Saturation
Homogeneous Tank Results
Air/Water
Diagonal cross section Gas fractional flow
contour plots
Poor displacement of liquid at the base of the
tank
In situ generated foam
Good displacement of liquid at the base of the
tank
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Foam Increases Gas Sweep Efficiency and Gas
Saturation
Heterogeneous Tank Results
Air/Water
Diagonal cross section Gas fractional flow
contour plots
Poor displacement of liquid at the base of
the tank
In situ generated foam
Good displacement of liquid at the base of the
tank
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Different Injection Strategies
Homogeneous Pack, Bottom sampling layer, 1 PV gas
injected
Constant injection pressure 0.8 psi
Constant Injection Rate 0.39 LPM (injection
pressure lt 0.4 psi)
Intermittent Gas injection
Continuous Gas injection

• The injection pressure should be high enough to
  generate strong foam and get better gas sweep
  efficiency.
• For a constant injection pressure, the
  intermittent injection method provides better gas
  sweep efficiency and higher total gas saturation
  than the continuous injection method.

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Comparison of Injection Rate
Experimental condition Homogeneous sand pack,
0.8 psi constant injection pressure
Air/Water Case
In foam case, at steady state, gas injection rate
is 1/30 lower than in air/water case
Foam Case
In 1-D, foam mobility is much lower
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Diagonal Cross Section Pressure Profile
heterogeneous sand pack
Injection pressure
Air/ Water
Injection pressure
In air/water case P1 gt P2 In foam case
P1 lt P2
Foam
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Foam Stability
Heterogeneous Pack, Constant injection pressure
0.8 psi 1 PV gas was injected and then gas
injection was stopped
Gas bubbles flow up
Water flows down
Heterogeneous tank with foam after 1PV gas
injection
Gas saturation in the tank is high and remains
almost the same 20 days after stopping gas flow.
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Simulation Approach
Observation Foam mobility
Larger scale 3-D field application
3-D tank experiments (Expensive, Time consuming)
1-D Experiments (Easy to perform in lab)
Obtain parameters
Simulate predict
Foam model
?
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Foam Changed Two Gas Flow Properties
Darcys law governs gas flow in porous media
No foam
Two gas properties are changed when foam is
present
Gas relative permeability
With foam
Gas apparent viscosity
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Details of the Model
Parameters
Represents difference between 1-D and 3-D
Can be determined from 1-D column experiments
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Parameter Determination from 1-D Column
Injection pressure Injection pressure ft/day
40 darcy sand column 0.2 psi/ft 0.4 2 0.2 0.8 5.60 2,700 1
40 darcy sand column 0.4 psi/ft 0.4 2 0.2 0.8 5.04 4,500 1
40 darcy sand column 0.8 psi/ft 0.4 2 0.2 0.8 5.08 8,010 1
40 darcy sand column 1.6 psi/ft 0.4 2 0.2 0.8 4.92 8,080 1

200 darcy sand column 0.2 psi/ft 0.7 6 0.4 0.84 12.10 650 1
200 darcy sand column 0.4 psi/ft 0.7 6 0.4 0.84 11.77 1,200 1
200 darcy sand column 0.8 psi/ft 0.7 6 0.4 0.84 11.65 2,140 1
200 darcy sand column 1.6 psi/ft 0.7 6 0.4 0.84 11.40 3,150 1
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Foam, 1-D Column, Simulation Results
40 darcy sand, (0.4psi/ft) Grid block20x1x1
ft/day
0.4 2 0.2 0.8 5 4,500 1
Average gas saturation after 1 PV gas injection
Exp 82 Simu 84
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Foam, 3-D tank history match simulationHomogeneou
s sand pack, (0.4 psi/ft) Grid block 9x9x9
Gas Injection Rate
Pressure Profile
Cross section gas fraction flow contour plots
Other parameters are the same as in the 1-D
simulation, except
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Comparison of 1-D and 3-D
In the homogeneous sand tank, under our
experimental condition, 3-D foam flow is about 5
times weaker than 1-D foam.
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Scaling Up Criteria for Larger Scale
Assumption The pressure drop is mainly within
the gas front
Criteria Use the overall pressure gradient
in the gas front when it reaches the edge of
a 2x2x2 ft region (NWR) as the comparison
standard to choose corresponding simulation
parameters from 1-D
i.e. Injection pressure 8 psi over hydrostatic
pressure The overall pressure gradient when gas
front reaches the NWR is 4 psi/ft Simulation
parameters will then be chosen from a
corresponding 4 psi/ft 1-D column experiments.
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Conclusions

• Foam increases lateral gas distribution and gas
  saturation in the 3-D sand tank
• To generate foam and get good sweep efficiency, a
  critical injection pressure must be exceeded.
• For the same injection pressure, the stabilized
  injection rate with foam is about 1/30 of that
  with surfactant-free water.
• The foam is stable. Most of the injected gas
  remains in the tank for more than 3 weeks.
• A foam model is proposed. Parameters can be
  determined from 1-D column experiments and
  applied to 3-D simulation. In the homogeneous
  sand tank, under our experimental condition, 3-D
  foam flow is about 5 times weaker than 1-D foam.

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