Increasing atmospheric concentrations of greenhouse gases are known to be causing a gradual warming of the Earth's surface and potentially disastrous changes to global climate. Since carbon dioxide is a major greenhouse gas, CO2 sequestration is being explored as one possible approach to limit the accumulation of greenhouse gases in the atmosphere. Sequestration covers technologies that capture carbon at its source (e.g., power plants, industrial processes) and directs it to non-atmospheric sinks (e.g., depleted oil and gas reservoirs, deep saline formations, deep ocean), as well as processes that increase the removal of carbon from the atmosphere by natural processes (e.g., forestation). To understand the process of gas flow in saline formations, in this study, computer simulations as well as experimental studies of multi-phase gas-liquid flows in a lattice-like flow-cell were performed. In the experiment, the displacement of a two immiscible fluids in the flow-cell was analyzed. Different orientations of the cell, as well as different liquids were tested. Flow patterns during the gas injection into the saturated cell were studied and the residual saturation of the phases and fractal dimensions of the gas-liquid interface were evaluated. Computational simulation of the flow cell is also performed using the Fluent™ code for the experiment flow-cell. Since the experimental flow-cell channels had random width and depth, a picture from the physical cell was vectorized in a CAD package that was used in the Gambit™ preprocessor and a two dimensional computational grid was developed. Residual saturation of the phases and fractal dimensions of the gas-liquid interface were evaluated from the numerical simulation and are compared with the experiment.

Flow Cell

Abstract

COMPUTATIONAL AND EXPERIMENTAL STUDY OF MULTI-PHASE FLUID FLOW THROUGH FLOW CELLS

(WITH APPLICATION TO CO2 SEQUESTRATION)

Department of Mechanical & Aeronautical Engineering

Kambiz Nazridoust, Joshua Cook and Goodarz AhmadiClarkson University, Potsdam, NY 13699-5727

http://www.clarkson.edu/fluidflow/kam/research/ Governing Equations

Conclusions

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Continuity:

Momentum:

Large Eddy:

Computational Model

Experiment Setup

Reduce CO2 Emissions By Sequestration In Deep Geological Formations

Depleted Oil and Gas Reservoirs Coal Seams Deep Brine-Fields

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ii

t

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v

11

Darcy’s Law for Two-Phase Flow:

Objectives Provide More Detailed Description of Two-Phase Flow During CO2

Sequestration Develop Better Understanding of Displacement of Oil, Gas, or Brine by CO2

Study effects of Gravity and Flow Rate on Two-Phase Flow through Porous Media Using Synthetic Porous Media (Flow cell)

100mm

100mm

• Parts similar to whole, even if approximate or statistical

• Too irregular for traditional geometrical language

• Fractional or “fractal” dimension that is a non-integer number

• Fine Structure (structure on some arbitrarily small scale)

Downward Flow, Q = 2.8 mL/min

t = 9 sec

t = 11 sec

t = 14 sec

t = 59 sec

Horizontal Flow, Q = 0.2 mL/min

t = 92 sec

t = 143 sec

t = 173 sec

t = 254 sec

Upward Flow, Q = 1.4 mL/min

t = 3 sec

t = 9 sect = 215 sec

t = 11 sec

Pressure Evolution with Time for Horizontal Flow, Q = 0.2 mL/min

Pressure Drop vs. Time

0

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1200

1400

0 50 100 150 200 250 300 350

Time (sec)

Pre

ssu

re (P

a)

Flow Enters Cell

Breakthrough

Horizontal Flow, Q = 8.0 mL/min

t = 5 sect = 3 sec

t = 4 sec t = 26 sec

Fractals

Results

<x> =∫x S(x,t)dx

∫S(x,t)dx

• <x> - average position• x - distance in flow direction• S – saturation of air

Average Position of Injected Fluid

Fractal Growth Compact Growth

<x> t<x> t 1/(Df-1)

Pressure Evolution with Time for Downward Flow, Q = 1.0 mL/min

Pressure Drop vs. Time

0

100

200

300

400

500

600

700

800

900

1000

0 10 20 30 40 50 60 70 80

Time (sec)

Pre

ssur

e (P

a)

Breakthrough

• Flow shows predicted behavior: Limiting regimes with a crossover region.

• Fractal dimension at breakthrough generally decreases as instability of the system increases.

• Maximum saturation of air ~ 38% occurs for least unstable flow configuration which is vertically downward flow and for lowest flow rate.

• Numerical results are in quantitative agreement with the experimental results.

• Simulation results show similar flow behavior to the experiment in upward flow and the effects of the gravitational force.

Results (in progress)