Page 554 - Environment: The Science Behind the Stories

Hydraulic fracturing expands our access
to oil and gas

For oil and for natural gas trapped tightly in imperme-
able shale deposits, we are now using hydraulic fractur-
ing (see Figure 7.1, p. 181) to break into rock formations
and pump the oil or gas to the surface. Hydraulic fracturing
(also called hydrofracking, or fracking) is being used for
secondary extraction and also to tap into new deposits. This
technique involves pumping chemically treated water under
high pressure into deep layers of shale to crack them. Sand
or small glass beads are inserted to hold the cracks open as
the water is withdrawn. Gas or oil then travels upward, with
pressure and pumping, through the newly created system of
fractures.
Hydraulic fracturing allows us to extract gas and oil that
is so dispersed through shale formations that it cannot be
pumped out by standard drilling. By making formerly inac- FIGURE 19.14 Hydraulic fracturing is expanding U.S.
cessible deposits accessible, hydrofracking has raised proven production of oil and natural gas, but it is sparking debates
reserves and has ignited a boom in natural gas extraction in the within communities where it is taking place. This drill rig is
United States. Natural gas prices have fallen, and gas usage in hydrofracking a shale formation on private land among homes in
the United States has risen. the rural Hopewell Township of Pennsylvania. Here, some residents
Fracking has engendered debate among people living in support drilling and hope for financial benefits whereas others
each area where it has occurred (FIGURE 19.14). For exam- oppose drilling and fear contamination of their drinking water and
ple, hydrofracking of the massive Marcellus Shale deposit is damage to their quality of life.
affecting the landscapes, economies, politics, and everyday
lives of people in Pennsylvania, New York, and neighbor-
ing states (see Chapter 7). The choices people face between the largest accidental oil spill in history. British Petroleum’s
financial gain and impacts to their health, drinking water, Macondo well, where the accident took place, lay beneath
and environment have been dramatized in popular films 1500 m (5000 ft) of water. The deepest wells in the Gulf of
such as Promised Land and Gasland. As with Alberta’s oil Mexico are now twice that depth.
sands, and like all energy booms before it, today’s natural Globally, recent discoveries off the coasts of Brazil, Angola,
gas rush brings jobs and money to small towns but can also Nigeria, and other nations suggest that a great deal of oil and gas
spark social upheaval and leave communities with a legacy could lie well offshore, and companies are racing one another
of pollution. to get there. Unfortunately, our ability to drill in deep water has
outpaced our capacity to deal with accidents there. The fact that
it took 86 days for BP to plug the leak at its Macondo well dem-
We are drilling farther and farther offshore onstrates the challenge of addressing an emergency situation a
mile or more beneath the surface of the sea.
Today we drill for oil and natural gas not only on land but Today all eyes are on the Arctic. As global climate change
also below the seafloor on the continental shelves. Offshore melts the sea ice that covers the Arctic Ocean (pp. 516, 521),
drilling platforms must withstand wind, waves, and ocean cur- new shipping lanes are opening and nations and companies are
rents. Some are fixed, standing platforms built with unusual scrambling to lay claim to patches of ocean that could hold fos- CHAPTER 19 • FOSSIL FUELS, THEIR IMPA CT S, AND ENERGY CONSERVATI ON
strength. Others are resilient floating platforms anchored in sil fuels and other resources. The oil and gas industry plans to
place above the drilling site. Roughly 35% of the oil and 10% drill offshore in deep water—something that has environmen-
of the natural gas extracted in the United States today comes tal advocates very worried. The Arctic’s frigid temperatures,
from offshore sites, primarily in the Gulf of Mexico and ice floes, winds, waves, and brutal storms make conditions
secondarily off southern California. The Gulf today is home harsh and challenging and make accidents more likely.
to 90 drilling rigs and 3500 production platforms. Geologists In 2008, responding to rising gasoline prices and a desire
estimate that most U.S. gas and oil remaining to be extracted to lessen dependence on foreign oil, the U.S. Congress lifted
occurs offshore and that deepwater sites in the Gulf of Mexico a long-standing moratorium on offshore drilling along much
alone may hold 59 billion barrels of oil. of the nation’s coastline. The Obama administration in 2010
We have been drilling in shallow water for several dec- followed through by designating vast areas open for drilling
ades, but as oil and gas are depleted at shallow-water sites that had formerly been closed. These included most waters
and as drilling technology improves, the industry is moving along the Atlantic coast from Delaware south to central
into deeper and deeper water. This poses risks; the Deepwater Florida, a region of the eastern Gulf of Mexico, and most
Horizon oil spill of 2010 (pp. 454–455, 556–559) occurred at waters off Alaska’s North Slope. However, just weeks after
a deepwater site. In that event, faulty equipment allowed natu- this announcement, the Deepwater Horizon spill occurred.
ral gas accompanying the oil deposit to shoot up the well shaft. Public reaction forced the Obama administration to back-
It ignited atop the platform, killing 11 workers and leading to track, canceling offshore drilling projects it had approved and 553

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