Canada Hydrates Get Close Study

The recent discovery by geophysicists from the University of Victoria of a spectacular gas hydrate glacier outcropping on the sea floor of Canada's Pacific margin has focused attention on this most unconventional energy resource.

There's a lot at stake: About 50 percent of Canada's landmass is underlain by permafrost, and trapped below the terrestrial permafrost layers are massive volumes of gas hydrates – locked in sedimentary rocks – that may contain enough energy to dwarf Canada's conventional gas reserves.

The key to establishing gas hydrates as a significant energy resource for Canada, however, is whether the methane gas that is frozen within a lattice of water molecules can ever be produced economically and safely.

During the winter of 2002, working in subzero temperatures and under cover of darkness in the Canadian Arctic, an international consortium led by the Natural Resources Canada's Geological Survey of Canada (GSC) and the Japan National Oil Corp. spent C$25 million to evaluate gas hydrates as a potential energy source. Gas flares from the world's first production tests of gas hydrates lit up the Arctic sky at the Mallik 5L-38 well, situated on Richards Island in the Mackenzie Delta and adjacent to the Beaufort Sea.

Mallik represents one of the world's most concentrated gas hydrate fields. Discovered by Imperial Oil in 1971-72 with the Mallik L-38 exploration well, gas hydrate saturations in the field average more than 60 percent and, in some cases, exceed 90 percent of the pore volume. Porosities in the poorly consolidated reservoir average about 40 percent.

In 1998, the GSC was involved in the drilling of Mallik 2L-38, a research well that identified at least 10 discrete gas hydrate intervals, exceeding 110 meters in total thickness.

"We recognized that the natural laboratory was correct," said David Boerner, an executive director of the GSC. "The consortium was built around the basic idea that we had fairly easy access to a large, known occurrence of gas hydrates."

Easy access for oil and gas exploration in Canada's Northwest Territories means barging the drilling equipment 1,500 kilometers up the Mackenzie River during the summer to a staging ground in the Mackenzie Delta.

It also means constructing 200 kilometers of ice roads to transport the drilling equipment and camp to the Mallik drill site.

Scott Dallimore is a research scientist with the Terrain Sciences Division of the GSC, and the scientific coordinator of the 2002 Mallik research well project.

"Gas hydrates are amazing deposits that only exist at atmospheric pressures for fleeting moments," Dallimore said.