Environmental Engineering Reference
In-Depth Information
the oil field for the oil to flow out under its own pressure. Later on it is
usually necessary to inject, or re-inject, gas or water into the field to keep
the pressure up and, therefore, the oil flowing. Traditionally, oil wells have
been drilled straight down.
But increasingly drillers branch out horizontally or sideways out of the
main oil wells, in order to reach more pockets of oil without littering the
land or seascape with drilling rigs. This form of drilling, which is also
known as directional drilling, has been made possible by the develop-
ment of steerable rotary drills. It can be done for as far as ten kilometres,
as BP has shown by drilling under Poole harbour from its Wytch Farm
oil well on the English south coast. In 1990 Iraq claimed that neighbour-
ing Kuwait was using slant drilling to steal Iraqi oil, a claim it invoked to
justify its invasion of Kuwait that year.
The top six oil producers in 2008 (millions of barrels a day)
Saudi Arabia
10.8
Russia
9.88
United States
6.73
Iran
4.32
China
3.79
Canada
3.23
World production*
81.8
Source:
BP Statistical Review
The top six oil consumers in 2008 (millions of barrels a day)
United States
19.4
China
7.99
Japan
4.84
India
2.88
Russia
2.79
Germany
2.5
World consumption*
84.4
Source:
BP Statistical Review
*Consumption was slightly higher than production because of stock changes, non-petro-
leum additives and substitute fuels.
