Foam Enhancement of sweep in Fracture System
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Transcript of Foam Enhancement of sweep in Fracture System
Foam Enhancement of sweep in Fracture System
Wei YanGeorge J. HirasakiClarence A. MillerChemical Engineering Department, Rice University
Objective• Study the diversion of liquid in
heterogeneous fracture network with foam
Foam flow in fractures experiment setup
Fracture model
Syringe pump
Air mass flow controllerFoam generator
Computer for recording pressure difference
Surfactant solution
Air
Transducer
Frit
HP digital camera
Experiment conditionsSurfactant: 0.5% C13-4PO+0.5% CS330Salinity: 0.23% NaCl, 0.07% CaCl2, 0.04%
MgCl2Aperture: 0.1mm, 0.2mm, 0.1 mm/0.2 mm
(1:2), 0.05 mm/0.15 mm (1:3)Fractional gas flow: 0~0.9Bubble diameter: 0.4 mm, 0.6 mm
Mechanisms affecting apparent viscosity in fracture system
Homogeneous parallel plates model
14 inch
12 inch
8 inch6 inch
Variable thickness
Effect of flow rate and gas fractional flow on apparent viscosity aperture = 0.2 mm,mean bubble size DB= 0.6 mm
0.1
1.0
10.0
100.0
0.001 0.010 0.100 1.000
Flow velocity (m/s)
App
aren
t vis
cosi
ty (c
p)
fg=0.67fg=0.67 from theoryfg=0.5fg=0.5 from theoryfg=0.33fg=0.33 from theoryfg=0.2fg=0.2 from theoryfg=0.0fg=0.0 from theory
Re=30Re=0.5
Re=0.5 Re=30
Water front at different Reynold’s number
Effect of bubble size on apparent viscosity
0.5% C13-4PO+0.5% CS330,0.23% NaCl, 0.07% CaCl2, 0.04% MgCl2,
gas fractional f low = 0.67, aperture = 0.2 mm
0.1
1.0
10.0
100.0
0.1 1.0 10.0
Mean bubble size (mm)
Appa
rent visco
sity
(cp)
f low velocity=2.2 cm/s
flow velocity=2.2 cm/s fromtheory
Heterogeneous parallel plates model
14 inch12 inch
8 inch6 inch
Variable thickness
10 inch
0.1 mm
Foam has higher apparent viscosity at larger thickness Match of apparent viscosity from theory and measurement
aperture = 0.05mm/0.15mm,DB=0.4mm,Re = 0.22
1
10
100
0 0.2 0.4 0.6 0.8 1Gas Fractional Flow
App
aren
t vis
cosi
ty (c
p)
0.05mm aperture from measurement
0.05mm aperture from theory
0.15mm aperture from measurement
0.15mm aperture from theory
0.15 mm thickness
0.05 mm thickness
Foam improves sweep of fractured system Less liquid is needed to sweep system with foam
LPV – Liquid Pore volume
Aperture = 0.05 mm / 0.15 mm, Re = 0.22, DB = 0.4 mm
fg=0.0
0.41PV 0.82 PV 1.23PV 1.64 PV 2.05 PV 6.56 PV
fg=0.9
0.04 LPV 0.08 LPV 0.12 LPV 0.16 LPV 0.21 LPV 0.66 LPV
Surfactant solution to sweep entire heterogeneous fracture at different aperture ratio in total pore volume
DB=0.4mm, Re=0.22
0.1
1.0
10.0
0.0 0.2 0.4 0.6 0.8 1.0Gas Fractional Flow
Tota
l Por
e Vo
lum
e
1:3
1:2
Surfactant solution to sweep entire heterogeneous fracture at different aperture ratio in liquid pore volume
DB=0.4mm, Re=0.22
0.1
1.0
10.0
0.0 0.2 0.4 0.6 0.8 1.0Gas Fractional Flow
Liqu
id P
ore
Volu
me 1:3
1:2
The model to describe flow in heterogeneous parallel plates
P1
P2
P3
P4
P1=P2 P3=P4
ImpermeableDykstra-Parsons Model
DB=0.4mm, Re=0.22aperture 0.05mm/0.15mmDykstra-Parsons model
0.1
1.0
10.0
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0Gas Fractional Flow
Tota
l Por
e Vo
lum
e
0.05mm aperture from experiment
0.05mm aperture from theory
0.15mm aperture from experiment
0.15mm aperture from theory
Injection to breakthrough in wide and narrow aperture
Calculation of sweep efficiency in fracture networkFracture apertures are with log-normal
distributionNo crossflowPressure difference is equal for each
layerGas fractional flow is equal in each
layer
Calculation of foam/water sweep in heterogeneous fractures with log-normal distribution apertures
Set bubble diameter=0.1mm
Simulation of foam/water sweep in heterogeneous fractures with log-normal distribution apertures
Set bubble diameter=0.1mm
Conclusions The foam apparent viscosity in heterogeneous
fracture is from two contributions-bubble deformation and liquid slugs between bubbles. The measurement corresponds to the theory.
Gas fractional flow and fracture thickness ratio can greatly affect the sweep efficiency.
Foam can greatly improve the sweep efficiency in heterogeneous fracture.
Dykstra-Parsons model can be applied to simulate the transient state foam flow in heterogeneous fractures
Future work
Test surfactants’ ability to generate foam in alkaline-surfactant EOR process
Study the foam stability with the presence of oil