The United States Geological Survey announced on Thursday that there may
be 3.0-4.3 billion barrels of "
undiscovered, technically
recoverable oil" in the Bakken shale formation,
discussed briefly here at How the World Works yesterday. The USGS said
it was the largest "continuous oil accumulation" it had ever assessed. For
comparison purposes, the Alberta oil sands are thought to have 175 billion
to 300 billion barrels of recoverable oil, and Saudi Arabia claims upward
of 260 billion. So while 4.3 billion might seem like a big number, it's
not quite the big leagues.
According to the USGS press release announcing the results of
the assessment, "a 'continuous' oil accumulation means that the oil
resource is dispersed throughout a geologic formation rather than existing
as discrete, localized occurrences."
Translation: technically recoverable, but it ain't gonna be easy.
Here's how the
Associated Press characterized the task ahead:
About two-thirds of the acreage is in western North Dakota, where the
oil is trapped in a thin layer of dense rock nearly two miles beneath
the surface. Companies use pressurized fluid and sand to break pores in
the rock and prop them open to recover the oil ...
Oil companies began sharing technology about two years ago on how to
recover the oil. The technology involves drilling vertically to about
10,000 feet, then "kicking out" for as many feet horizontally, while
fracturing the rock to release the oil trapped in microscopic pores in
the area known as the "middle" Bakken.
This process, known as "horizontal drilling" may not involve the same
kind of wholesale rock pulverization usually associated with shale oil
recovery, but it still sounds like a hugely energy-intensive, expensive
mess.
― Andrew Leonard
U.S. Geological Survey
reports that there could be a few billion barrels of oil underneath the
Dakotas. But knowing it's there and getting it out are two very
different things. Andrew Leonard
[2008-04-10]
Typical of news reporters who know nothing of technology but have an
opinion about it, I live in an oil rich area of Alberta, conventional
oil and not the oil sands further north. I am not involved in any way
with any of it and admit to not being too happy with the energy sector's
often lack of sensitivity to the environment but the comment by the
author regarding horizontal drilling obviously being a big energy
consuming mess is frankly anti tech bull. Horizontal drilling has been
going on for a long time..perhaps a decade or more and it well described
in journals and is used to catch smaller deposits that are now
profitable that heretofore were left untouched. One well does the deed
rather than a number of drillings and thus, contrary to the comment, it
is less of a mess and more sensible, lower in energy costs and so forth.
The Bakken deposit which is huge and covers not only North Dakota but
parts of Saskatchewan, Manitoba and so forth is a 30 or so metre thick
deposit of dense oil bearing stone but it is a contiguous body and thus
amenable to horizontal drilling techniques and the processes of fracing
as it is called ( pronounced frak-ing) opens the dense materials to
permit the oil to flow into the created channels. This particular oil is
a huge find as it is of a low density measured to 41 degrees which is
high grade sweet oil and not the tar sands oil as in the ATHABASCA OIL
SANDS area of Alberta which is nastier to extract. Rather than complain
about it as a new mess to contend with, better, drink a glass of bubbly
so that you guys can keep driving those fat cat SUVs another few years.
For me as a Canadian, I am glad you found it so that there will be
somewhat less pressure to build yet more oil/tar sands plants here which
has resulted in the impossibility for a normal person to find any
employees, driven up prices and lowered the quality of life in Alberta
for anyone not associated with that industry. No doubt the USGS is being
conservative as to the size of the find as there are competent people
around that say that it is more like 400 billion barrels of oil in that
deposit and with tech coming around the corner, it will be a lot bigger
than the 4 billion described. Incidentally, Saskatchewan's side of this
deposit is half as deep in the ground and will be easier to access so
the oil will be flowing and not such a mess at all.
-- NeilFiertel