346
Water for Energy and Fuel Production
1. Preliminary depressurization to a point above the freezing point of the
aqueous phase opens pore space for injection of mobile fluids.
2. Kinetics of the direct exchange of hydrate formers (i.e., CO 2 with CH 4 ) are
important.
3. Cage occupancies of the sI structure are expected to have significant
impacts on the efficiency of direct gas-phase CO 2 –CH 4 exchange.
4. Controlling secondary hydrate formation is critical to prevent pore plugging.
5. Heat transfer into the production zone is not required under properly controlled production conditions.
One critical finding of the above-described Battelle’s simulation modeling work was
that the formation of secondary CO 2 hydrate has the potential to halt the production
process by inhibiting fluid migration. A complete exchange of CO 2 and CH 4 is possible without forming excessive secondary hydrate and while maintaining elevated
hydrate saturations. The pore-water salinity may play a strong role in the inhibition
of secondary hydrate formation beyond certain saturation levels, an observation in
agreement with the published experimental results [73].
12.5.7 CommerCiAl APPliCATionS
In the recent years, the above-described production methods and computer simulations have been applied to numerous practical sites [33,222,227–234]. The North
Slope of Alaska and numerous sites in that region (such as Mallik field, Milne point)
have been tested [33,222,227–229]. Nankai Trough [231] and Ulleung basin of the
Korea [233] have also been examined. Several general production strategies have
also been investigated [216,234–237]. More work on the applications (both theoretical and experimental) of various production methods to the commercial sites
(both on land and in deep water) is needed. The successful commercial operations to
recover methane from gas hydrates will significantly increase our energy resource.
Once again, water is the cause for this important energy and fuel source.
reFerenCes
1. Englezos, P., “Clathrate Hydrates,” Industrial & Engineering Chemistry Research,
32 (7), 1251–1274 (1993).
2. “What are gas hydrates?” a communication by Center for Gas hydrate Research, HeriotWatt University, Edinburgh, The Hydrate forum Org. (2012).
3. Boswell, R. and Collett, T.S., “Current perspectives on gas hydrate resources,” Energy
and Environmental Science, 4, 1206–1215 (2011).
4. Collett, T.S., Johnson, A.H., Knapp, C.C., and Boswell, R. (eds.), “Natural gas hydrates:
A review,” in Natural Gas Hydrates—Energy Resource Potential and Associated
Geologic Hazards, AAPG Memoir 89. AAPG, Tulsa, OK, 146–219 (2009).
5. McIver, R., “Gas hydrates,” in Meyer, R. and Olson, J. (eds.), Long-Term Energy
Resources. Pitman, Boston, MA, 713–726 (1981).
6. Collett, T.S. “Gas hydrates as a future energy resource,” Geotimes, 49 (11), 24–27 (2004).
7. Sloan, E.D. and Koh, C., Clathrate Hydrates of Natural Gases, 3rd ed. Taylor & Francis,
Boca Raton, FL (2008).
Water for Energy and Fuel Production
1. Preliminary depressurization to a point above the freezing point of the
aqueous phase opens pore space for injection of mobile fluids.
2. Kinetics of the direct exchange of hydrate formers (i.e., CO 2 with CH 4 ) are
important.
3. Cage occupancies of the sI structure are expected to have significant
impacts on the efficiency of direct gas-phase CO 2 –CH 4 exchange.
4. Controlling secondary hydrate formation is critical to prevent pore plugging.
5. Heat transfer into the production zone is not required under properly controlled production conditions.
One critical finding of the above-described Battelle’s simulation modeling work was
that the formation of secondary CO 2 hydrate has the potential to halt the production
process by inhibiting fluid migration. A complete exchange of CO 2 and CH 4 is possible without forming excessive secondary hydrate and while maintaining elevated
hydrate saturations. The pore-water salinity may play a strong role in the inhibition
of secondary hydrate formation beyond certain saturation levels, an observation in
agreement with the published experimental results [73].
12.5.7 CommerCiAl APPliCATionS
In the recent years, the above-described production methods and computer simulations have been applied to numerous practical sites [33,222,227–234]. The North
Slope of Alaska and numerous sites in that region (such as Mallik field, Milne point)
have been tested [33,222,227–229]. Nankai Trough [231] and Ulleung basin of the
Korea [233] have also been examined. Several general production strategies have
also been investigated [216,234–237]. More work on the applications (both theoretical and experimental) of various production methods to the commercial sites
(both on land and in deep water) is needed. The successful commercial operations to
recover methane from gas hydrates will significantly increase our energy resource.
Once again, water is the cause for this important energy and fuel source.
reFerenCes
1. Englezos, P., “Clathrate Hydrates,” Industrial & Engineering Chemistry Research,
32 (7), 1251–1274 (1993).
2. “What are gas hydrates?” a communication by Center for Gas hydrate Research, HeriotWatt University, Edinburgh, The Hydrate forum Org. (2012).
3. Boswell, R. and Collett, T.S., “Current perspectives on gas hydrate resources,” Energy
and Environmental Science, 4, 1206–1215 (2011).
4. Collett, T.S., Johnson, A.H., Knapp, C.C., and Boswell, R. (eds.), “Natural gas hydrates:
A review,” in Natural Gas Hydrates—Energy Resource Potential and Associated
Geologic Hazards, AAPG Memoir 89. AAPG, Tulsa, OK, 146–219 (2009).
5. McIver, R., “Gas hydrates,” in Meyer, R. and Olson, J. (eds.), Long-Term Energy
Resources. Pitman, Boston, MA, 713–726 (1981).
6. Collett, T.S. “Gas hydrates as a future energy resource,” Geotimes, 49 (11), 24–27 (2004).
7. Sloan, E.D. and Koh, C., Clathrate Hydrates of Natural Gases, 3rd ed. Taylor & Francis,
Boca Raton, FL (2008).