Oil and Natural Gas - Energy Policy Analysis: A Conceptual Framework - page 85

suspected the heavy use of chemical dispersants at the wellhead on the sea floor may have broken
the oil into droplets too small to rise rapidly, producing plumes at 2,300 to 4,200 feet deep in
the sea. The impacts of possible oxygen depletion caused by such plumes on marine flora and
fauna were of considerable concern, and some feared they might create large “dead zones” on
the seabed (Gillis 2010).
In August 2010, University of Georgia oceanographer Samantha Joye suggested that three-
quarters of the oil spilled into the gulf—about 3 million barrels—remained in marine ecosystems
there (Sutter 2010). Her empirical field research contradicted an earlier report from the National
Oceanic and Atmospheric Administration that three-quarters of the oil had disappeared from the
ecosystem. Joye's research at various locations near the BP Deepwater Horizon site collected
numerous seabed core samples containing several centimeters of flocculated oil deposited from
above, which distinguished them from natural seabed oil seeps (Joye 2010). More recent surveys
in November 2010 discovered extensive damage to deep sea corals near the BP Deepwater Horizon
site, appearing to support Joye's hypothesis (Burdeau 2010). Research into the impacts of this
enormous oil spill had only just begun at this writing, and it appears we may learn a great deal more
about the environmental damage done by the BP Deepwater Horizon spill in the coming years.
Refining and Processing
Activities associated with oil and gas development often cover large areas, especially in shore
land areas. Each of these activities entails disturbance of land and its dedication to a single use
for as long as development and production continue. Such facilities and structures include oil and
gas treatment facilities and refineries; crude oil storage tanks; supply and crew boat bases; oil
and gas pipeline terminals; temporary support bases for onshore and offshore pipeline installa-
tion activities; and use of existing or expanded airports for helicopter support activities (USDOI
1986, IV.A.65).
TAR SANDS
Bituminous oil sands, or tar sands, present a special type of unconventional heavy crude oil so
thick it cannot be pumped from wells and requires special upgrading before it can be refined or
transported by pipeline. Tar sands are naturally occurring mixtures of sand, clay, water, and a dense,
extremely viscous form of petroleum known as bitumen, which has a tar-like appearance, odor,
and color. This thick, sticky form of crude oil is so heavy and viscous it will not flow unless heated
or diluted with lighter hydrocarbons or chemical solvents, appearing much like cold molasses at
room temperature (Government of Alberta 2008b). Although there are large reserves in Utah and
small deposits in Alabama, Texas, California, Kentucky, Alaska, and some other states, in 2011
there was no commercial production from tar sands in the United States. In 2008 Canada supplied
about 20 percent of U.S. oil consumption, almost half from tar sands (USBLM 2008).
Making liquid fuels from oil sands requires considerable energy for steam injection and up-
grading, before refining. This generates two to four times the amount of greenhouse gases per
barrel of final product as production of conventional petroleum (Romm 2008, 181-182). Including
combustion of the final products, oil sands extraction, upgrade, and use of tar sands emits 10 to
45 percent more greenhouse gases than conventional crude oil (Weber 2009).
Because bitumen flows very slowly, if at all, toward producing wells under normal reservoir
conditions, tar sands must be extracted by strip mining or the oil made to flow into wells by in
situ techniques, which reduce the viscosity by injecting steam, chemical solvents, or hot air into