Methane Recovery from Gas Hydrates

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Methane Recovery from Gas Hydrates
Walter G. Chapman Chemical Engineering
Dept. Rice University
US Geological Survey
www.gashydate.de/images/hand.jpg
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What are Gas Hydrates?
Self-assembled nano-structures formed by the
cooperative hydrogen bonding of water molecules
to create polyhedron cages around small
molecules. Methane trapped in a single
Pentagonal Dodecahedra Cage From US Geological
Survey.
Comparison of ice and hydrate structures. One of
the hydrate cages is shown to contain a methane
molecule. From the Naval Research Laboratory
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Motivation for Production

• Vast Energy Resource
• Increased Demand for Methane
• Fuel with Reduced CO2 Emissions
• More Efficient Power Production than from Oil or
  Coal Fired Plants
• Source for H2 for Fuel Cells
• Energy Security for Countries Lacking Energy
  Resources

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Production Technologies

• Thermal Injection
• Circulating Hot Formation Brine
• Electrical or Electromagnetic Heating
• Hot Water or Steam
• In-Situ Combustion

Produced Gas
Sea floor
Dissociated Hydrate
Hydrate Containing Sediment
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Production Technologies

• Chemical Injection
• CO2
• Hydrate Inhibitor (methanol)

Power Plant
CO2
CH4
Sea floor
Hydrate Containing Sediment
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Production Technologies

• Pressure Depletion
• Free Gas Production

Produced Gas
Sea floor
Hydrate Containing Sediment
Free Gas
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Production Response

• Possible Production from Messoyakha Field
• Possibly 36 of the production (5 billion m3)
  from hydrates (Makogan, 1981)
• Nankai Trough Southeastern Coast of Japan
• Mallik Production Test is Ongoing (Northern Coast
  of Canada)
• Hot Ice 1 North Slope of Alaska Anadarko in
  Collaboration with DOE

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Production Issues

• High Concentration of Hydrates
• Production Strategy Depends on Accumulation
  Process
• Seafloor Stability
• Reservoir Model (Accumulation and Production)
• Reservoir Heterogeneity
• Lithology and Permeability of the formation
• Brine Flux
• Heat Effects and Thermal Conductivity
• Mechanism and Rate of Dissociation

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Why are Hydrates Interesting?

• Pipeline Plugging
• Preventing Gas Hydrate formation accounts for
• 10-15 of the production costs
• 500 Million per year for inhibitors alone

www.spe.org/cda/images/ hydrate.jpg
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Why are Hydrates Interesting?

• Environmental Modeling
• Potential Release of Greenhouse Gases

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Why are Hydrates Interesting?

• Other Potential Applications
• Transport and Storage of Natural Gas
• Gas Separations and Materials Handling
• Templates for Novel Nano-Materials

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Summary

• There is twice as much carbon in hydrates than in
  all other known fossil fuel deposits
• Hydrates are a dynamical system with
  environmental implications
• Commercial production from hydrates is probably
  10-20 years away
• Expertise exists on the Rice Campus Riki
  Kobayashi, Jerry Dickens, Ed Billups, George
  Hirasaki, Walter Chapman