One of the banes of deepwater oil and gas recovery is the tendency of the control lines and pipelines to be plugged by an ever present material called methane hydrate. When this compound leaves the elevated temperatures of the subterranean world and encounters the cold temperatures of the sea floor at the high pressures at the wellhead, it “freezes” or forms a lattice like structure that looks like ice and is very effective at plugging flow lines. We saw that happen when the Macondo well shut in processes were in process, it was the reason that the first “top hat” recovery operation failed.
Click pic to enlarge.
Because it has this annoying characteristic, it is common to use chemical injection to prevent the methane hydrate from freezing, these chemicals range from methanol to other chemical cocktails that are injected into the well stack and allowed to mix with the outflow to prevent the freezing.
Why is this annoyance significant? Well, for four reasons.
The first reason is that methane hydrate is really just a crystalline combination of a natural gas and water (known technically as a clathrate). It looks remarkably like ice but burns if ignited, the Inuit word for it is “iġnik sikumi” or literally “fire ice”.
The second is the amount of it. According to the Department of Energy quoted in Forbes last week:
“While global estimates vary considerably, the energy content of methane occurring in hydrate form is immense, possibly exceeding the combined energy content of all other known fossil fuels.”
This stuff is truly plentiful, it lies in easily recoverable depths starting at 300 meters (as opposed to the 1600 meter depth (a mile) of the Macondo wellhead) and it permeates the seabed in depths estimated to be hundreds of meters. It is also locked in substantial quantities in the ice covered expanses at the north and south poles.
The third is that Conoco Phillips in a partnership with the Department of Energy has developed a process to recover usable methane from the clathrate and Royal Dutch Shell has a process to convert it into jet fuel and diesel that works with shale gas, too. Up until these efforts, there were no commercially viable solutions and the methane was “flared off” as it reached the topside. It just wasn’t economical to capture and process.
The fourth reason is in the detail of the process itself. The way that they recover the methane is to inject carbon dioxide to replace the methane in the ice matrix, freeing the methane and sequestering the CO2.
They’ve done it in a laboratory: Scientists have injected carbon dioxide into the kind of methane ice that underlies vast tracts of permafrost in the Arctic and lurks beneath the deep seafloor throughout the world.
In that experiment, the carbon dioxide exchanged with the methane molecules. While the CO2 was sequestered inside the ice, the scientists extracted an energy source that may exist in nature in greater volume than all other fossil fuels combined.
Now DOE’s National Energy Technology Laboratory, in partnership with Conoco Phillips, will try to repeat that success on the North Slope of Alaska.
NETL and Conoco Phillips have completed installation of a well they call “Iġnik Sikumi”— using Iñupiaq terms for “fire in the ice”—NETL announced yesterday. The well will be available for experimental operations this winter.
At that time, the scientists will begin injecting carbon dioxide into the well and capturing freed methane.
So there is a bonus for the enviro lobby, we can recover a clean form of energy while sequestering a greenhouse gas. It also has a free enterprise benefit by changing a waste stream into a revenue stream. Generators of CO2 will now have a commercial reason to capture it for sale.
Natural gas is clean to burn and it yields a waste stream that is immediately cleaner than gasoline, diesel or coal and is far easier to “scrub” before being released into the environment. Far from reaching “peak oil” or “peak energy”, there is still abundant energy available that will not require a return to the Stone Age or destroy industrialized economies. These are the types of efforts that need to be undertaken to achieve real results.