Environmental Engineering Reference
In-Depth Information
Oil exploration technology
There have been many ingenious advances in oil exploration and production
over the years:
Seismic technology
A process similar to the use of sonar waves and
echolocation to detect objects underwater or in the air, seismic technology
involves beaming energy waves at the earth's surface or seabed and
constructing a picture of the subsurface from how these energy waves are
reflected by the earth's crust. It is essential technology for oil geologists. They
have successively developed two-dimensional (2d) seismic to create a picture
of a narrow cross-section of the earth's crust, then 3d seismic to widen this
cross-section, and even, in recent years, 4d seismic to add the dimension of
time, indicating any likely movement or flow of liquids.
Horizontal drilling
This reaches a wide range of oil and gas pockets from
one drilling, rig. It does not always refer to literally 90˚ drilling but simply
to any wells that are more or less horizontal. It has a distinct advantage in
that it can access oil resources impeded by surface obstructions, such as
bodies of water or buildings. The US Department of Energy has indicated
that horizontal drilling can lead to an increase in reserves of 2% of the
original oil in place. The production ratio for horizontal wells versus
vertical wells is 3.2 to 1, while the cost ratio of horizontal to vertical wells
is only 2 to 1.
Enhanced oil recovery
The injection of water, natural gas, steam or
liquid carbon dioxide into wells facilitates the extraction of oil from them
by increasing the pressure within them. The natural pressure or gravity on a
deposit will normally only push between five and fifteen percent of the oil out
of the well. But if water or gas is pumped in, up to another thirty percent can
be extracted. Reducing the viscosity or glueyness of the oil by pumping in
steam can extract still more.
Deepwater drilling
Much of the growth in non-OPEC oil output, especially
in the “golden triangle” of the Gulf of Mexico, off Brazil and off West Africa,
has been achieved by drilling in deep water (between 400 and 1500 metres)
and in ultra deepwater (deeper than 1500 metres). The advent of deepwater
drilling has turned conventional wisdom about offshore oil exploitation on its
head.
to develop those reserves, how much time it takes, how much realistically
you need.” Meanwhile, Sadad al-Huseini, the former head of exploration
and production for Saudi Aramco, has provided an analysis showing that
global oil production has already hit a plateau and is unlikely to rise above
current levels.
In contrast, the IEA projects - on the basis of policies in force before the
United Nations climate summit of December 2009 in Copenhagen - that
