Page 89 - Intelligent Digital Oil And Gas Fields

60 Intelligent Digital Oil and Gas Fields

For these methods to work requires real-time data readings for pressure
and temperatures, so one must install instruments to gather necessary data.
Instrumentation is discussed in Chapter 5.

2.1.3.7 Flowmeter Selection
DOF workflows can provide significant value to justify the investment in
accurate flow measurement of all phases and sometimes even compositions.
Flowmeters should not be selected on cost or price, but on the accuracy
needed to support the value-added workflows. Table 2.1 summarizes the
factors for selecting flowmeter devices based on: principles of measurement,
property to be measured, reservoir fluid most applicable, GOR range of
operation, water cut range of operation, accuracy as a function of flow rate,
turndown maximum and minimum reading rates, and vendor tolerance.

2.2 CONTROL TECHNOLOGY BY FIELD TYPES
2.2.1 General Control Technologies
The most important control technology for realizing the maximum benefits
of the DOF is remote or autonomous means for controlling a well. The best
example of this technology is the automatic choke.
An automatic choke lets you remotely adjust the flow in a well—from
complete shutdown to restart and nearly every setting in between. This
capability can be useful in many operating situations; for example, wells
can be curtailed or shut down when problems arise in production facility
equipment, then, when the problem is solved, remotely restarted. Many
operators are adding these chokes as standard equipment, especially for rap-
idly declining wells where the chokes can be adjusted remotely as rates
decline and wells can be easily set up with intermittent flow to support
field-wide capacity management.
Other important automatic technologies are for artificial lifts. Gas-lift
valves need to be highly accurate (not on-off ) regulatory valves. Electric
submersible pumps (ESP) should have adjustable frequency drives, and
rod pumps should have pump-off controllers and remote-activated speed
adjustments.
This section provides recommendations for use of these technologies for
some important types of fields.