1

Validation of Models Simulating Capillary and Dissolution Trapping During Injection and Post-Injection of CO2 in Heterogeneous Geological

Formations Using Data from Intermediate Scale Test Systems (FE0004630)

Abdullah Cihan

Lawrence Berkeley National Laboratory

U.S. Department of Energy

National Energy Technology Laboratory

Carbon Storage R&D Project Review Meeting

Developing the Technologies and Building the

Infrastructure for CO2 Storage

August 21-23, 2012

Research Team

Tissa Illangasekare, Luca Trevisan, Elif Agartan, Hiroko Mori

Colorado School of Mines

Jens Birkholzer, Quanlin Zhou and Marco Bianchi

Lawrence Berkeley National Laboratory

2

Presentation Outline

Benefit to the Program

Project Overview

Technical Status

Task 2 – Intermediate-scale laboratory testing of

capillary and solubility trapping in homogeneous and

heterogeneous systems

Task 3 – Evaluation of whether existing modeling

codes can capture the processes observed in the

laboratory, and developments of the constitutive

models based on the findings

Accomplishments to Date

Project Summary - Findings and Future Plans

Appendix

3

Benefit to the Program

Overall Project Goals

Improve/develop and validate models by using the data

generated in intermediate-scale laboratory test systems

simulating capillary and dissolution trapping under

various heterogeneous conditions.

Design injection strategies, predict storage capacities and

efficiency for field-scale geological systems by using the

improved numerical tools

The findings will meet objectives of Program research to develop

technologies to cost-effectively and safely store and monitor CO2

in geologic formations and to ensure storage permanence.

Developed approach and technologies in this project specifically

contribute to the Carbon Storage Program’s effort of supporting

industries’ ability to predict geologic storage capacity to within +/-

30 percent.

4

Knowledge gaps and

research questions

5

Heterogeneity and Capillary Trapping

In naturally heterogeneous formations, injected scCO2 will preferentially

migrate into higher permeability zones and pool under the interface of the

confining low permeability layers due to capillary barrier effects (very high

entry pressure).

Low permeability

High permeability

Pooling

Injection

Knowledge gaps exist on how the

heterogeneity influences capillary

trapping of CO2.

6

Heterogeneity and Dissolution Trapping

Dissolution of CO2 in heterogeneous systems can

be enhanced due to increases in interfacial areas

between water and supercritical CO2.

Knowledge gaps exist on how the heterogeneity

influences dissolution trapping of CO2.

7

Capillary Trapping

How do heterogeneities and connectivity (spatial continuity of

different permeability zones) affect entrapment efficiency of scCO2 in

deep geological formations?

How well the existing continuum-based models and the constitutive

models capture multiphase flow behavior of scCO2 /brine in deep

formations?

Dissolution Trapping

What are the effects of heterogeneity on dissolution and density-

driven fingers?

Can dissolution of CO2 in heterogeneous systems be enhanced due to

increases in interfacial areas between water and supercritical CO2?

Research Questions

8

Task 1 – Project Management and Planning

Task 2 – Generate data in intermediate scale test tanks

simulating capillary trapping and dissolution affected by

heterogeneity

Task 2.1 – Small tank experiments

Task 2.2 – Large tank experiments

Task 3 – Evaluate whether the existing modeling codes can

capture processes observed in the test tanks, and improve

existing models based on findings

Project Objectives and Tasks

9

x

y

0.5 1 1.5 2 2.5 3 3.5 4 4.5

0.2

0.4

0.6

0.8 0.9

0.75

0.6

0.45

0.3

0.15

Wetting FluidSaturation

Time = 1 day

A multi-scale experimental testing

and modeling

Size (cm to basin scale)

Mo

de

l D

ime

nsio

n

S

0.6

0.55

0.5

0.45

0.4

0.35

0.3

0.25

0.2

0.15

x

y

0.02 0.04

-0.04

-0.02

Exp

eri

me

nt D

ime

nsio

n

LBNL

Field

Scale

Pc (Pa)

Co

nn

ec

tiv

ity

1000 1500 2000 2500 30000

0.2

0.4

0.6

0.8

Primary Drainage

Main Wetting

Approach

Intermediate-Scale

1 to ~ 10 m

10

10 20 30 40 50 60 70

x-coordinate (cm)

0

10

20

30

40

50

z-coord

inate

(cm

)

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

interface

NA

PL s

atu

ration

Experimental Methods

Automated transient and spatially

distributed saturations using x-ray

attenuation

Aqueous sampling to determine

dissolved plume concentrations, and

core destructive sampling from

low permeability zones

Core destructive sampling to determine

final entrapment saturations.

Measurement of multiphase model parameters (capillary pressure-

saturation-relative permeability relationships)

11

Task 2 – Experimental Studies

Selection of materials and fluids

Dimensional analysis (Bo, Ca, density and viscosity ratio, Ra number)

Small test systems in fluid/fluid media and small sand tanks

(28cmx15cm)

Small tank experiments (28cmx15cm and 92cmx1.2m)

Capillary trapping in homogeneous and simple heterogeneous

packing (8 experiments completed)

Analyses of density-driven finger developments in homogeneous and

heterogeneous packing (4 experiments completed)

Capillary trapping in highly heterogeneous systems (in progress)

Capillary and dissolution trapping (homogeneous and heterogeneous

packing)

Large tank experiments (4.9mx1.2m)

Capillary trapping (in progress)

Capillary and dissolution trapping

12

Material and Fluid Selection

Laboratory investigation of scCO2 migration without high

pressure can be conducted using analogous fluids having

similar density and viscosity contrasts as scCO2 – brine

phases under sequestration conditions

Dimensionless

Numbers

scCO2-brine

@ Typical

Reservoir

Conditions

Soltrol220-

glycerol/water

@ 20C, 1 atm

Water in

Propylene

Glycol @ 20C,

1 atm

Methanol in

glycerol/water

@ 20C, 1 atm

Bond # ~ 10-7 - 10-8 ~10-6- 10-7 ~10-6- 10-7 ~10-6- 10-7

Capillary # ~ 10-5 - 10-8 ~10-6- 10-7 ~10-7- 10-8 ~10-7- 10-8

Viscosity Ratio ~ 0.05 - 0.2 ~0.074 ~0.017 ~0.07

Density Ratio ~ 0.2 – 0.8 ~0.66 ~0.9 ~0.6

nw TuCa

g kBo

nw

w

nw

w

13

Testing of the Scaling Approach

scCO2-water system

Test Fluids

Identical results can be obtained if the same

dimensionless numbers are chosen for the geometrically

similar two systems (Shook et al., 1992; Gharbi et

al.,1998).

1

10

100

1000

10000

400

600

800

1000

1200

1400

0 20 40 60 80 100

visc

osi

ty (

cP)

den

sity

(kg

/m3

)

glycerol percent by mass

density

viscosity

Glycerol/water mixture at

ambient conditions

14 74 cm

52

cm

8 cm 8 cm

gra

ve

l

Sand #30

10 cm

11 cm

8 c

m

Sand #110

Sand #205 cm

55 cm

25

cm

Mariotte bottle

(constant

pressure)

Constant head

10 cm

11 cm

2.3

cm

Small Tank Experiments For Capillary Trapping in

Homogeneous and Heterogeneous Systems

Injected fluid: Soltrol 220

Displaced fluid: Glycerol-Water mixture (80%-20% w/w)

A total of 8 small tanks experiments with both homogeneous and

heterogeneous packing completed.

Plume injection and plume configuration recorded.

Soil samples removed and the fluids extracted to determine final

entrapment saturations.

Bottom plate

15

Small Tank Experiments for Capillary

Trapping in Mildly Heterogeneous Systems

Can models that use macroscopic multiphase parameters capture the flow

and entrapment behavior ?

Are the relative permeability models generated from retention functions

adequate?

What are the effects of injection rates (entrapment zone development and

final entrapment saturations) ?

Does the final entrapment depend on rate of injection?

Heterogeneous with a continuous

high-permeability layer

T1=6hr30min

T2=72hr

0.22

0.19 0.13 0.13

T1=8hr30min

T2=90hr30min

0.180.160.13

0.200.16

Heterogeneous with a discontinuous

high-permeability layer

16

Small Tank Experiments in Highly Heterogeneous Systems (in progress)

x

y

0.2 0.4 0.6 0.8

0.05

0.1

0.15

0.2

0.25

0.3

KSX

1.1E-10

3E-11

2E-11

x

y

0.2 0.4 0.6 0.8

0.05

0.1

0.15

0.2

0.25

0.3

S0.85

0.75

0.65

0.55

0.45

0.35

0.25

0.15

0.05

A computer-generated

realistic heterogeneous aquifer

3 3 3 3 2 2 3 3 1 1 1 3 3 3

3 3 3 3 3 3 3 3 3 3 3 1 1 3

3 2 2 3 3 3 1 1 1 1 3 3 3 3

3 3 3 3 2 1 2 2 2 2 3 3 3 3

3 3 3 3 3 3 1 2 2 3 3 2 2 2

2 2 2 2 3 3 3 3 1 1 1 1 1 3

3 3 3 3 3 3 3 3 3 2 2 3 3 3

3 3 3 3 2 2 1 3 3 3 3 3 3 3

WE

LL

Simplified for packing

Very fine sand

(Cap rock)

red (#30) Coarse

green (#50) Medium

blue (#70) Fine

Repair of X-ray systems will be

completed at the end of August

For phase

saturation

measurement

17

Small-Tank Experiments: Heterogeneity effect on density-driven fingering (water/propylene glycol )

Fingering is dampened out by heterogeneity

From high permeability medium to low permeability

medium, finger flow is replaced by bulk flow

#45/#50

#50/#70

18

Problems encountered in early design of the 16ft large tank experiment were

mostly resolved

Large Tank Experiments (in progress)

Well configuration => non-wetting phase

moves upward inside the well; only top

portion of the screen injects Soltrol into

the aquifer (reduced vertical sweep)

Difficulties to avoid preferential pathway

between confining layer and gasket

# 8

#110 + #250

# 8

#50/70

Constant head B.C.

Constant head B.C.

Previous Current Setup for the Large Tank

Experiments

With groundwater flow

4.88 m

19

Task 3 – Modeling

Guiding the laboratory experiments

Injection rate and period, sampling frequency, different packing

configurations, and effect of different boundary conditions; i.e.,

constant head versus no flow.

Testing continuum models and upscaling methodologies

Verify models (numerical codes solving classical two-phase flow

equations) based on experimental measurements in homogeneous

and heterogeneous experiments

Test/develop constitutive models for accurate prediction of the CO2

entrapment

Utilize improved modeling and up-scaling tools to predict the

effective capillary and dissolution trapping at actual reservoir

conditions and large scale CO2 storage scenarios

Design injection strategies to optimize CO2 trapping.

20

Model Testing

Small tank experiment in a mildly heterogeneous domain

with a continuous high-permeability zone – During Injection

VG-Mualem & Corey Relative perm. from Previous

Results in Air-water Exp.

systems

2 hr

7.5 hr

Time

0.2 0.4 0.6 0.8

0.2 0.4 0.6 0.8

S

0.6

0.55

0.5

0.45

0.4

0.35

0.3

0.25

0.2

0.15

21

Model Testing

Small tank experiment in a mildly heterogeneous domain with a

discontinuous high-permeability zone – During Injection

1 hr

2 hr

6 hr

Time

x

y

0.2 0.4 0.6 0.8

0.2

0.4

0.6

x

y

0.2 0.4 0.6 0.8

0.2

0.4

0.6

x

y

0.2 0.4 0.6 0.8

0.2

0.4

0.6S

0.6

0.55

0.5

0.45

0.4

0.35

0.3

0.25

0.2

0.15

22

T1=6hr30min

T2=72hr

0.22

0.19 0.13 0.13

Saturation distributions at the end of the experiments

Two-phase model results with hysteresis effects

Model Testing

x

y

0.2 0.4 0.6 0.8

0.2

0.4

0.6S

0.6

0.55

0.5

0.45

0.4

0.35

0.3

0.25

0.2

0.15

0.1

0.05

T1=8hr30min

T2=90hr30min

0.180.160.13

0.200.160.13

0.18 0.16

0.16 0.20

Simple Heterogeneous Packing

S

0.6

0.55

0.5

0.45

0.4

0.35

0.3

0.25

0.2

0.15

0.1

0.05

23

Development of a Theoretical Hysteresis Model

1

, ,

1

( ) 1 ; , 1,2, ,jm m

d d

nw c m i ij ik d m c

i j i k i

S P f p p P P m n

, , , ,

1

1

Represents the fraction of pores filledwith non-wetting phase at the endofdrainage

' 1 ; , , 1, ,1

' 1

in iw w

nw c m nw c n i ij ik d m c m

i m j m k j

lnd d

i i il ik

l i k i

S P S P f p p P P m n n

f f p p

Drainage

Pc (Pa)

Co

nn

ec

tiv

ity

1000 1500 2000 2500 30000

0.2

0.4

0.6

0.8

Primary Drainage

Main Wetting

Imbibitions

1 2

1 2, , ,

n

n

r r r

f f f

Volume Fractions

Void Sizes

SW

Pc

(Pa

)

0 0.2 0.4 0.6 0.8 1

4000

6000

8000

10000

FLOW REVERSAL - 1

FLOW REVERSAL - 2

FLOW REVERSAL - 3

FLOW REVERSAL - 4

FLOW REVERSAL - 5

FLOW REVERSAL - 6

Connectivity parameters are

obtained from measured

capillary pressure-saturation

curves or computer-generated

pore network models

24

Preliminary Results Verification of the Hysteresis Model

Water Content

Pc

(Pa

)

0 0.1 0.2 0.3 0.4

3000

4500

6000

7500

Model

Experiment (Computer-generated)

Primary Drainage

Main Wetting

0.00E+00

2.00E-02

4.00E-02

6.00E-02

8.00E-02

1.00E-01

1.20E-01

1.40E-01

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

With computer-

generated data

With laboratory experiments in

LV60 sand with Octane/brine

(Pentland et al. 2010)

Model

Non-wetting phase saturation

(at the end of injection)

Re

sid

ua

l sa

tura

tio

n

25

Modeling in the Large Tank and Effect of Heterogeneity

Four-Facies Case, Sands #30, #50, #70, #110

Time (days)

Ma

ss

(kg

)

0 2 4 6 8 10 12 140

2

4

6

8

10

4 facies- R1

4 facies- R2

4 facies- R3

SOIL NUMBER

PR

OB

OF

CO

NN

EC

TIV

ITY

1 2 3 40

0.2

0.4

0.6

0.8

1

Realization-1

Realization-2

Realization-3

Control Volume

More mass retained in Realization-

2 as a result of less connectivity of

higher-permeability zones

Higher k Lower k

Large-scale capillary entrapment

affected by connectivity!

26

Model Simplification Through Upscaling

0.5 1 1.5 2 2.5 3 3.5 4 4.5

0.2

0.4

0.6

0.8

S

0.6

0.5

0.4

0.3

0.2

0.1

0.5 1 1.5 2 2.5 3 3.5 4 4.5

0.2

0.4

0.6

0.8

S

0.34

0.28

0.22

0.16

0.1

Sw

Pc

(Pa

)

0 0.2 0.4 0.6 0.8 10

5000

10000

15000

20000

25000

30000

Sw

kw

x,k

wy

,k

nx

,k

ny

0 0.2 0.4 0.6 0.8 1

10-31

10-26

10-21

10-16

10-11

kwx

kwy

knx

kny

Effective

Constitutive

Relationships

27

Accomplishments to date

Task 2 – Experiments in intermediate-scale Selected and tested surrogate fluids

Small tank experiments completed for testing capillary trapping and

density-dependent fingers in homogeneous and simple heterogeneous

systems

Initiated large tank experiments for capillary trapping

Task 3 – Modeling Developed a multiphase flow solver (based on the Finite Volume

method) for analysis of the experimental data and new constitutive

models and non-equilibrium mass transfer

Simulated the two-phase flow in small tank experiments and compared

the model results with experimental data

Developed a new code for analyzing heterogeneity: Computes

connectivity based on invasion percolation algorithm. This code also

involves algorithms to upscale two-phase flow parameters.

Developed a new hysteresis model and tested against few data sets

28

Project Summary

Findings The numerical model based on the classical two-phase flow

theory was able to capture the main features observed

during the migration of the CO2 surrogate fluid in the small

tanks

Incorporating hysteresis effects into the numerical models

required for accurate prediction of post-injection capillary

entrapment.

Intermediate-scale heterogeneity (existence of lower and

higher permeability zones) enhances the capillary

entrapment.

Density-driven convective mixing in highly heterogeneous

formations may not be important.

29

Project Summary

Future Efforts Obtain quantitative data on temporal and spatial

saturation changes using the X-ray system

Complete measurements of relative permeability of the

sands in separate homogeneous column tests

Update the model results in the small tank with measured

relative permeability curves in separate homogeneous

column tests

Intermediate-scale heterogeneous experiments and

models involving both capillary and dissolution trapping.

Improve the numerical models by incorporating the

validated constitutive models

30

Questions?

31

Appendix: Organization and Gantt Charts

32

Task 1.0 – Project Management and Planning

Illangasekare

(PI/PD)

CSM Team

(experiments)

LBNL team

(modeling)

Luca Trevisan

(PhD student)

Cihan

Birkholzer Zhou

coordination coordination

Elif Agartan

(PhD student)-

partial

Hiroko Mori

(MS student)-self

Sakaki

Bianchi

33

Updated Time Line

Task BP 1 BP 2 BP 3

Tanks assembly and setup

Experimental methods

Homogenous immiscible

Homogenous miscible

Heterogeneous

immiscible

Heterogeneous miscible

Modeling

February 2012 November 2010

34

Appendix: Bibliography

35

Backup Slides

36

Capillary

trapping

Dissolution

trapping

Mineralization

Leakage

Injection

Deep geologic formation

Goal

Maximize

Minimize/

Prevent

Maximize

Maximize

Select site with

least potential

and risk

Strategy

Use

heterogeneity

to increase total

CO2 trapping/

water interfacial

area

Design Strategy

37

Physically based theory for predicting entrapment

In conventional multiphase flow modeling approaches, residual

non-wetting phase content are either calculated based on

empirical relationships or fitted from experimental data.

There is no physically based theory predicting entrapment of CO2

in homogeneous and heterogeneous systems.

Pore scale

Water

CO2

Ca

pil

lary

Pre

ss

ure

Saturation

CO2 injection

CO2 drainage

Capillary entrapment

38

12 hours later 1 day later 5 days later 1 week later

Coarse Sand

Medium Sand

Fine Sand

Rayleigh

Number

Small Tank Experiments: Density-driven fingering and

(water/propylene glycol) in homogeneous domains

Rayleigh Number for scCO2-brine @ Typical Reservoir

Conditions ~ 6 - 103

39

Heterogeneity and Capillary Trapping

Entrapment efficiencies of CO2 (defined as the total mass trapping

per unit volume of the formation) in relatively homogeneous and

highly heterogeneous systems can be quite different. Knowledge

gaps exist on how the heterogeneity influences capillary

entrapment of CO2.

Cap rock

Injection

Homogeneous Heterogeneous

Fine soil Fine soil

Coarse soil Random

40

Small Tank Experiments for Capillary Trapping

A total of 8 small tanks experiments with

both homogeneous and heterogeneous

packing completed.

Plume injection and plume configuration

recorded.

Soil samples removed and the fluids

extracted to determine final entrapment

saturations.

Goal is to generate a data set for

validation of models to simulate

macro-scale processes of capillary

entrapment

Small tank (90 cm x 60 cm x 5.6 cm)

Mariotte bottle with Soltrol 220

on an automated balance

41

Large Tank Experiments: Design and assembly

of large tanks for confined conditions

4 ft

5 cm

X-ray attenuation

For phase saturation

measurement

Ports for aqueous

sampling

Sloping capping layer

42

Conceptual Model :

Near-Pore-Scale Macroscopic Invasion Percolation

Problem domain discretized into a grid (two- or three-dimensional) with a chosen critical

“throat” or critical “pore”, rm, values assigned to each grid block for nonwetting or

wetting fluid invasion (Glass et al., 2001, WRR)

A grid block contains a small void space characterized with a rm value.

x (m)

y(m

)

0 0.01 0.02 0.03 0.04 0.05-0.05

-0.04

-0.03

-0.02

-0.01

0

x (m)0 0.01 0.02 0.03 0.04 0.05

No Trapping

Drainage path Imbibitions path

2,

c a w

m

Young Laplace Equation P P Pr

43

Development of Constitutive Models

Using Pore Connectivity

Drainage

Assumptions:

During drainage, the largest pores drain first

During wetting, the smallest pores fill up first

2,

c a w

m

Young Laplace Equation P P Pr

1 11 1

1 2 12 11 1 22 2

1

2 1

i p f

i p p f p f

11

12 22

5 / 6

1, 54 / 60

p

p p

44

Development of A Theoretical Hysteresis Model

11

12 22

13 23 33

1 2 3

d

d d

d d d

d d d

n n n

p

p p

p p p

p p p

1 2

1 2, , ,

n

n

r r r

f f f

,

, 1 1, 1

, 2 1, 2 2, 2

,1 1,1 2,1

w

n n

w w

n n n n

w w w

n n n n n n

w w w

n n n

p

p p

p p p

p p p

Volume Fractions

Pore Sizes

Connectivity for the

Drainage Paths

Connectivity for the

Imbibitions Paths

x

y

0.02 0.04

-0.04

-0.02

x

y

0.02 0.04

-0.04

-0.02

Large Pores

Small Pores

Small Pores

Large Pores

45

0.22

0.19 0.13 0.13

With hysteresis S

0.6

0.55

0.5

0.45

0.4

0.35

0.3

0.25

0.2

0.15

No hysteresis effects

Model Testing

A Small Tank Experiment – Post-Injection

46

T1=6hr30min

T2=72hr

0.22

0.19 0.13 0.13

Saturation distributions at the end of the experiments

Two-phase model results with hysteresis effects

Model Testing

x

y

0.2 0.4 0.6 0.8

0.2

0.4

0.6S

0.6

0.55

0.5

0.45

0.4

0.35

0.3

0.25

0.2

0.15

0.1

0.05

T1=8hr30min

T2=90hr30min

0.180.160.13

0.200.160.13

0.18 0.16 0.16 0.20

Heterogeneous Packings

S

0.6

0.55

0.5

0.45

0.4

0.35

0.3

0.25

0.2

0.15

0.1

0.05

47

Near-Pore Scale Invasion Percolation (sand#30)

Dependence of Residual Saturation on

Maximum Saturation

Wetting Phase

Non-wetting Phase

Trapped Non-

wetting Phase

Smax=0.40 Sr=0.11

End of Drainage End of Imbibitions

Smax=0.84 Sr=0.17

48

Wetting Phase

Non-wetting Phase

Trapped Non-

wetting Phase

Smax=0.40 Sr=0.11

End of Drainage End of Imbibitions

Smax=0.84 Sr=0.17

Pentland et al. 2010, SPE

Results show that the residual non-wetting phase saturation is strongly function of the saturation at the end of injection

Non-wetting phase saturation

(at the end of injection)

Dependence of Residual Saturation on

Maximum Saturation R

esid

ua

l sa

tura

tio

n

Near-Pore Scale Invasion Percolation (sand#30)