Page 11 - Oil and Gas Production Handbook An Introduction to Oil and Gas Production

2.1.1 Onshore

Onshore production is economically
viable from a few dozen barrels of oil
a day and upwards. Oil and gas is
produced from several million wells
world-wide. In particular, a gas
gathering network can become very
large, with production from thousands
of wells, several hundred
kilometers/miles apart, feeding
through a gathering network into a
processing plant. The picture shows a
well equipped with a sucker rod pump
(donkey pump) often associated with
onshore oil production. However, as
we shall see later, there are many
other ways of extracting oil from a non-free flowing well

For the smallest reservoirs, oil is simply collected in a holding tank and
picked up at regular intervals by tanker truck or railcar to be processed at a
refinery.

But onshore wells in oil rich areas are also high capacity wells with
thousands of barrels per day, connected to a 1,000,000 barrel or more a day
gas oil separation plant (GOSP). Product is sent from the plant by pipeline or
tankers. The production may come from many different license owners,
therefore metering and logging of individual well-streams into the gathering
network are important tasks.

Recently, very heavy crude,
tar sands and oil shale have
become economically
extractable with higher prices
and new technology. Heavy
crude may need heating and
diluents to be extracted. Tar
sands have lost their volatile
compounds and are strip
mined or can be extracted
with steam. It must be further
processed to separate
bitumen from the sand. These
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