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170 Part III Underbalanced Drilling Systems

Antifoam
Cyclone Onshore Water
Wellhead Treatment Facility
Water
(80gpm) Valve Blooey Line
Foamer
(0.08 gpm) Killer
Injector
Foam
Generator Water Shale
(3 gpm) Shaker

Foam Killer
(0.03gpm)
Surge
Tank
Active Disposal
Well Well
Figure 8.4 A foam separation system.

Blooey Line Return
To Air Pit or Separator
Nitrogen Recycle (gas buster)
pH

Cuttings Shaker P Acid
Acid Storage
Feed
Recirculation
Line
Supplemental
Defoamer Addition pH Alkali
(if necessary) Storage
Excess
Foam Alkali Feed
Overflow

Slop Pit Free Mud Pits Polymer Recovery Solution
Water Flocculant Ready for Reuse
Return Addition
Figure 8.5 A foam recycling system.

8.3 DOWNHOLE EQUIPMENT

Like surface equipment, some downhole equipment in liquid and
gas drilling operations—for example, some types of drill pipe valves—are
also used in UBD operations. Mud motors in liquid drilling are also used