Page 43 - Oil and Gas Production Handbook An Introduction to Oil and Gas Production

respectively. The chokes are set to reduce the wellhead flow and pressure to
the desired HP and LP pressures respectively.
The desired setting for each well and which of the wells produce at HP and
LP for various production levels are defined by reservoir specialists to
ensure the optimum production and recovery rate.

4.2 Separation

As described earlier, the well-stream may consist of crude oil, gas,
condensates, water and various contaminants. The purpose of the
separators is to split the flow into desirable fractions.

4.2.1 Test separators and well test

Test separators are used to separate the well flow from one or more wells for
analysis and detailed flow measurement. In this way, the behavior of each
well under different pressure flow conditions can be defined. This normally
takes place when the well is taken into production and later at regular
intervals, typically 1-2 months and will measure the total and component flow
rates under different production conditions. Undesirable consequences such
as slugging or sand can also be determined. The separated components are
analyzed in the laboratory to determine hydrocarbon composition of the gas
oil and condensate.

Test separators can also be used to produce fuel gas for power generation
when the main process is
not running. Alternatively, a
three phase flow meter
could be used to save
weight.

4.2.2 Production
separators
The main separators shown
here are gravity types. On
the right you see the main
components around the first
stage separator. As
mentioned before, the
production choke reduces
well pressure to the HP
manifold and first stage

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