Locked under ice and permafrost in Alaska and in remote
reaches of the Arctic lie vast resources to fuel our nation's energy
future. The tremendous volume of methane gas hydrates in the permafrost
regions of the world make tapping into this unconventional resource
a critical component to add to our nation's energy portfolio.
The antithetical extremes of this resource -- the potential of
fire captured in ice crystals -- make it a compelling challenge
to turn the unconventional into the conventional. While gas hydrates
hold great potential as an "environmentally friendly" fuel for the
21st century, considerable technological challenges currently hinder
using them as a resource. Their occurrence in icy and remote areas
without an infrastructure for delivery presents a daunting challenge.
There are scientific challenges as well -- we need to more fully
understand the geologic parameters controlling the occurrence and
distribution of gas hydrates in order to put a more accurate number
on the amount of methane sequestered as gas hydrates worldwide.
Resource estimates are currently speculative and range over several
orders of magnitude, from about 100,000 to 270,000 trillion cubic
feet, according to broad extrapolations done by U.S. Geological
Survey scientists in the 1990s (figure 1).
One of the most exciting aspects of the gas hydrate quest is the
tremendous opportunity for collaboration and innovative partnerships
between industry, government and academia.
The USGS has been a partner in the consortium for the Mallik Project
in the Mackenzie Delta of the Canadian Arctic, which involves Canada,
Japan, Germany, India and the United States, and more than 100 scientists
At the Mallik site, scientists and engineers conducted the first
fully integrated field study and production testing of a natural
gas hydrate accumulation, which is showing that this resource holds
considerable potential as a fuel source.
The Mallik site was chosen because it represents one of the world's
highest concentrations of gas hydrates.
Before Mallik, little was known about the technology necessary
to produce gas hydrates, and these first successful results -- shared
at an international symposium in Japan last December -- form the
world's most detailed scientific information about the occurrence
and production characteristics of gas hydrates.
(Detailed scientific and technical results are being published
in a joint volume of the partners and will be released this fall
as a Geological Survey of Canada publication.)
What we have learned from Mallik depressurization and thermal
heating experiments is that gas can be produced from gas hydrates
with different concentrations and characteristics, exclusively through
The data support the interpretation that the gas hydrates are
much more permeable and conducive to flow from pressure stimulation
than previously thought.
In one test, the gas production rates were substantially enhanced
by artificially fracturing the reservoir. Hydrates also were produced
using thermal heating in varying amounts.
Coalbed methane represents another unconventional resource with
great potential. The large and complex internal surface area of
coal enables it to store surprisingly large volumes of methane-rich
gas -- six or seven times as much gas as a conventional natural
gas reservoir of equal rock volume.
That large potential is sparking tremendous interest in this unconventional
resource, especially in Alaska, where the USGS recently assessed
Whereas previous coal resource assessments attempted to assess
the total coal in the ground -- producing estimates that tended
to be high -- and to include coal deposits that contain beds that
are too thin and/or too deep to be economically mined, this focused
on beds currently being developed in existing mines, or in areas
that are currently leased.
The assessment shows Alaska surpassing the total coal resources
of the conterminous United States by almost 40 percent -- an estimate
of more than 5,500 billion short tons, which translates to an exceedingly
large potential for coalbed methane, as much as 1,000 trillion cubic
feet of in-place CBM resource (figure 2).
Most of those resources are found in the northern Alaska-North
Slope and southern Alaska-Cook Inlet coal provinces where in-place
and planned infrastructure (pipelines, highways, etc.) may potentially
assist in mitigating the delivery challenges in the transportation
and marketability of coalbed gas.
This could be a considerable boon to the native Alaskan people
in remote areas. The USGS is working with native Alaskan groups,
the state of Alaska and Interior's Bureau of Land Management to
identify potential coalbed gas resources and to characterize the
potential of this resource for their energy needs.
Proximity to pipelines would mean that Alaska coalbed gas could
play a role in world supply. The short distance of coal and coalbed
methane resources to countries in the western Pacific Rim makes
them potentially more marketable to that sector of the world than
to the rest of the United States.
What about conventional resources in Alaska?
The USGS 2002 re-assessment of the National Petroleum Reserve
there showed that the federal part of NPRA contains significant
volumes of technically recoverable oil and gas resources spread
over a vast area. The same conundrum exists, however, for conventional
as for unconventional resources -- they're there but how do we get
them where we need them?
The economic viability of the natural gas resources depends on
the availability of transportation to the lower 48 and no natural
gas pipeline currently exists.
The USGS and its Energy Resources Program are committed to delivering
the energy resource information needed by land and resource managers,
energy policy makers, other scientists, academia, private industry
and the public at large -- to provide science for decisions, and
science for communities.
As USGS focuses this year on our 125th anniversary, we reflect
back on how energy resource information has long been an essential
part of our mission to "classify and examine" the national domain.
In his luncheon address to the EMD at last month's AAPG annual
meeting, USGS associate director for geology Pat Leahy stressed
the need for scientific research and new technology innovation as
the nation's resource base becomes, of necessity, more dependent
on unconventional resources. And nowhere is the "fire and ice" of
that unconventional potential of higher profile and greater promise
than in Alaska.
Working with national and international partners in industry,
government and the academic community, the USGS is dedicated to
providing the science that will ensure that we have the energy resources
to fuel our economies and foster a clean and safe environment for
(Editor's note: Additional USGS energy information is at http://energy.usgs.gov.)