Steam Flood (SAGD),
the Wabasca Field area thermal recovery process works on the same
simple principle as when your mother accidentally steam-ironed your
clothes the time you left chocolate in your pocket. The bitumen
(“chocolate”) melts and drips down into the production pipe below
(“runs down your pants”.) This high pressured, in situ, thermal
process may be at least partially responsible for the uncontrolled
bitumen blow-out at Cold Lake which contaminated over 150 acres of
water and forced the drainage of a polluted lake. This seemingly
unstoppable 2013 Tar Sands leak in six months has exceeded 300,000
gals and “has probably contaminated groundwater” according to
Alberta Environment officialsi.
Another tar sands pollution event could occur again at any time from
these very shallow, artificially pressurized, reservoirs due to a
fracking-like process that is virtually unregulated.
Figure
7
SAGD- Steam Assisted Gravity Drainage Production
SOURCE:
USGS
2003
All of these enhanced
production methods are important because as they act on the bitumen
to make it more mobile, they also begin to change the chemistry of
the oil. The hot steam not only melts the bitumen, it brings it into
contact with large amounts of water which releases acids and other
toxic chemicals into the oil. Unfortunately, the chemistry of the
Tar Sands is so complex (especially after combining with diluent)
that few of these toxic chemicals (polymers, solvents and
surfactants) are even recognized after a spill unless they are looked
for specifically with the latest detection equipment. This is no
consolation to residents like those near the Mayflower and Kalamazoo
spills, who are often assured that the area is safe to occupy by
people who don’t actually know what chemicals the tar sands oil
contain. In many cases, first responders do not even know what
chemicals they are actually dealing with which puts them at even
greater risk than they normally are when responding to conventional
oil spills.
i
Pratt,
Sheila, Edmonton Journal October 23, 2013
CNRL
bitumen leak has likely contaminated groundwater, report says
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