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 Generally considered a high-volume pump.
 Provides for increased volumes and water cuts brought on
by pressure maintenance and secondary recovery operations.
 Permits placing wells on production even while drilling
and working over wells in immediate vicinity.
 Applicable in a range of harsh environments.
ESPs have some disadvantages that must be considered.
 Will tolerate only minimal percentages of solids (sand)
production, although special pumps with hardened surfaces and
bearings exist to minimize wear and increase run life.
 Costly pulling operations and lost production occur when
correcting downhole failures, especially in an offshore
environment.
 Below approximately 400 B/D, power efficiency drops
sharply; ESPs are not particularly adaptable to rates below 150
B/D.
 Need relatively large (greater than 4½-in. outside diameter)
casing size for the moderate- to high-production-rate equipment.
Long life of ESP equipment is required to keep production
economical.

Gas Lift
Gas lift is a method of artificial lift that uses an external
source of high-pressure gas for supplementing formation gas to lift
the well fluids. The principle of gas lift is that gas injected into the
tubing reduces the density of the fluids in the tubing, and the
bubbles have a “scrubbing” action on the liquids. Both factors act
to lower the flowing bottomhole pressure (BHP) at the bottom of
the tubing. There are two basic types of gas lift in use today—
continuous and intermittent flow. This page briefly describes each
method and its advantages and disadvantages.
Continuous-flow gas lift is recommended for high-volume and
high-static BHP wells in which major pumping problems could
occur with other artificial lift methods. It is an excellent
application for offshore formations that have a strong waterdrive,
or in waterflood reservoirs with good PIs and high gas/oil ratios
(GORs). When high-pressure gas is available without compression

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