Page 16 - Oil and Gas Production Handbook An Introduction to Oil and Gas Production

gas back into the reservoir to maintain pressure and levels to maximize
production.

Once a natural gas or
oil well is drilled, and
it has been verified
that commercially
viable quantities of
natural gas are
present for extraction,
the well must be
'completed' to allow
for the flow of
petroleum or natural
gas out of the
formation and up to
the surface. This
process includes
strengthening the well
hole with casing, evaluating the pressure and temperature of the formation,
and then installing the proper equipment to ensure an efficient flow of natural
gas from the well. The well flow is controlled with a choke.

We differentiate between, dry completion (which is either onshore or on the
deck of an offshore structure) and subsea completions below the surface.
The wellhead structure, which is often called a Christmas tree, must allow for
a number of operations relating to production and well workover. Well
workover refers to various technologies for maintaining the well and
improving its
production capacity.

2.2.2 Manifolds/
gathering

Onshore, the
individual well streams
are brought into the
main production
facilities over a
network of gathering
pipelines and manifold
systems. The purpose
of these pipelines is to

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