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Equipment in Underbalanced Drilling Systems 171

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Figure 8.6 Halliburton’s deployment valve, the Quick-Trip Valve. (Courtesy of
Halliburton.)

in UBD for horizontal drilling. Some unique types of equipment that are
widely used in UBD are the deployment valves for underbalanced trip
operations. Both mechanically and hydraulically actuated valves are avail-
able in the oil and gas industry. Figure 8.6 shows a cutoff view of a
mechanically controlled deployment valve.
The deployment valve isolates the reservoir while tripping during dril-
ling operations. It establishes a mechanical barrier, eliminating the need to
kill the well. Mechanical actuation eliminates external control lines. It
enables the safe deployment of slotted liners or production screens with-
out killing the well. It can be a permanent or temporary installation.
Deployment valves make the UBD operations easier and safer.

SUMMARY

This chapter provided a brief introduction to some special types of
equipment that are used in UBD operations. Key equipment includes blow-
out preventers, 4-phase separators, and downhole deployment valves.