April 23, 2008 | 15 Comments
Canadian and Japanese researchers have managed to efficiently produce a constant stream of natural gas from ice-like methane gas hydrates from a remote drilling rig high in the Mackenzie River Delta on Richards Island in the Northwest Territories of Canada. Called the Mallik drilling program, for the first time, Canadian and Japanese researchers have managed to efficiently produce a constant stream of natural gas that, worldwide, dwarf all known fossil fuel deposits combined.
Scott Dallimore, from the Geological Survey of Canada, researcher in charge said, “We were able to sustain flow. It worked.” Getting methane hydrate gas to flow consistently and predictably, however, has been the problem. Using heat to release the gas works, but requires too much energy to be useful. Researchers have also been trying to release the methane by reducing the pressure on it. Then last month, the Mallik team became the first to use reduced pressure to get a steady, consistent flow.
Dallimore is quoted saying, “That went really well. We definitely demonstrated that these hydrates are responsive enough that you can sustain flow. We were able to take conventional technologies, modify them, and produce. That’s a big step forward.” The Mallik well produced methane gas for six days at a rate lower than conventional gas but about equivalent to a coal bed methane well as Dallimore explained.
This experimental result proves the basic idea works. The next step is a full-scale pilot project that would anticipate what goes into a commercial production rig, including safety and environmental concerns, and answering questions regarding how much water and sediment are produced per unit of gas.
The data is available to others. Japanese researchers are planning a full-scale methane hydrate project and the U.S. Geological Survey is trying to start one with other agencies and energy companies. Brenda Pierce of the U.S. Geological Survey said, “Everybody agrees this is what we need to do. It’s just (a question of) where. We’re trying to look at doing this on the north slope of Alaska.”
What is this stuff? Methane when thawed out, is the main and cleanest part of natural gas. Methane hydrates form at low temperature and high pressure, are found in sea-floor sediments and the arctic permafrost. They can be scattered through several-hundred-meter depths and at various concentrations. The discussion is continuing on how these deposits are formed. The only certainty is they are a result of biomass accumulations that nature has reconstructed into a hydrocarbon.
How much is there? Lots. Estimates range over three orders of magnitude, with the smaller estimates offering twice the total hydrocarbons as fossil fuels. The chart above shows the distributions nicely at the low end. What is actually commercially recoverable is something very much yet to be determined.
The news is quite good when flows of freed gas can be collected and used for fueling is considered. When methane released from hydrates becomes more developed, the amounts may be quite huge. But for today the breakthrough and the congratulations for the Canadian and Japanese cooperating team is the post’s prime mission. There is sure to be more later as some Russian project managers are insisting their sources are pressure releases from land reservoirs.
Finally here is a map of where methane hydrates are located. Just keep in mind that the survey of the inventory is in the very beginning stages. There is much more to find, understand and explore.
Carbon sources are soon to be seen as not being the problem, global warming not withstanding, as carbon is a very active and dynamic part of both the ecological process of life on earth as well as the geological carbon cycle. This is another example of the wonders of nature combing a molecule of carbon with four molecules of hydrogen making a great source of energy available for mankind.