“California peaked in light
crude oil in the 1960s. Heavy
oil started coming on due to
steam injection.”
~ David Olsen,
consultant to the
U.S. Department of Energy
standards, so new production is constrained by tough emission rules and
regulations. Because refining is done at
the U.S. Gulf Coast, thousands of
crude oil storage tanks dot the landscape on oilfields, which can be as
small as a few hectares. Leaks from
these tanks contribute to air pollution.
Although California producers
“recycle a lot of the water, steam is an
issue because they have shortages of
water. The majors sold their properties
to smaller companies because they
didn’t want to deal with small fields or
environmental problems,” says Eddy
Isaacs, managing director of the
Alberta Energy Research Institute (AERI)
in Calgary.
“California peaked in light oil in the
1960s,” Olsen says. “Heavy oil started
coming on due to steam injection. It
made up the production deficit as light
oil went down. Some of the same techniques you find being used in in situ—
essentially SAGD [steam assisted gravity
drainage] in the oilsands in Alberta—can
be used in California. You start off with
cyclic steam, then go to steam drive, but
having the ability to have horizontal
wells has enabled both the thick sands
in California and the thick sands in
Alberta to be developed.”
SAGD, of course, was developed in
Alberta with advances in directional
drilling, and now PTTC is suggesting
producers revisit the concept of injecting air to feed underground fire to
soften the oil, again because of
Alberta’s success with directional
drilling. In the 1960s and ’70s in
California, experiments with fire in vertical wells failed more than succeeded.
Tectonic activity played a role in
hydrocarbon formation in both
California and Alberta, according to
University of Alberta geophysicist Doug
Schmitt, a professor at the Institute for
Geophysical Research, Department of
Physics. “[California had] tectonic activity—lots of source rocks, and heat to
cook them, a deep basin that filled in
with sediments, marine deposits, and
marine shales. In Alberta, when the
Rockies were being formed, there was
a lot of tectonics going on here, things
got heated and bubbled up.”
Like Canadian bitumen, American
heavy oil is held in highly porous,
weakly consolidated sands. In the
Lloydminster, Cold Lake, Peace
River, and Athabasca fields of
Alberta, the oil coats sands deposited by 110-million-year-old rivers,
now deeply buried.
