Methane Hydrate Formation

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There are many challenges that aforementioned two extraction methods are facing, for example, the permeability of the methane hydrate formation and the ratio between energy input and output.
Depending on the location, methane hydrate formation exists in various forms. A certain formation can contain sand as host sediments with methane hydrate mixed within; similarly, the host sediment can be made of rock, clay, silt, or a mixture of each. Depending on the composition of the host sediment, the formation has different mechanical strength, porosity, permeability, degree of saturation and other parameter. Depending on the location, the permeability of the formation can vary for several degrees of magnitude. [15] When hot water, steam, or CO2 is
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As shown previously, methane hydrate contains 1 mole of methane for every 5.75 mole of water, corresponding to 13.4% methane by mass, in ideal situation. In reality, this number might be lower. Therefore, the actual energy housed within a methane hydrate formation is likely to be much lower than that of a conventional gas, coal, or oil formation with the same volume. Combining with the reality that a methane hydrate formation can exist with very low methane hydrate saturation (~5%), the energy housed within such formation will be even lower. Therefore, when extracting a methane hydrate formation, the maximum energy input for extraction is of consideration, since if the required input energy is larger than the theoretical output energy, the whole process will become commercially unfavorable. There is not enough statistical data to show the net energy output while using thermal injection method or CO2 injection method. But both of these methods are energy intensive. For thermal injection method, a constant stream of steam or hot water need to be produced and injected into the formation. While the constant production of steam or hot water is already energy intensive, the heat dissipation during injection is also considerable, since the formations are typically hundreds of meters underneath the seafloor or hundreds of meters deep in the permafrost. For CO2 injection method, the CO2
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