Page 170 - Well Control for Completions and Interventions

162 Well Control for Completions and Interventions

Table 4.3 Annular preventer seal selection table
Manufacturer Elastomer Color Supplier Manufacturers recommended use
code
Hydril Natural Black R Water-based fluids with less than 5%
rubber oil and operating temperature
greater than 230F. Suitable for
H 2 S service
Shaffer Natural Red 1 or 2 Low temperature operations with
rubber water-based fluids
Hydril Nitrile Red S Oil-based muds with aniline points
between 165 and 245F;
suitable for H 2 S service and
operating temperatures greater
than 20F
Shaffer Nitrile Blue 5 or 6 Oil- and water-based muds;
suitable for H 2 S service
Cameron Nitrile Black n/a Oil and water-based fluid;
suitable for H 2 S service
Temperature range from 230 to
250 F

Hydril Neoprene Green N Oil-based muds with operating
temperatures between 20 and
230 F; suitable for H 2 S service

fluid requirements, replacement part numbers, internal seal locations,
testing, etc.
• Check the annular manifold pressure gauge for the correct reading
according to the equipment operating manual.

4.7.6 Stripping with annular preventers

Annular preventers allow drill pipe to be stripped into a well, since they
can maintain a seal as a drill pipe connection passes. They also have better
abrasion resistance than ram preventers. However, stripping is unlikely to
be possible during most completion or workover operations, as threaded
and coupled connections rarely have enough taper to prevent seal dam-
age. Where stripping is possible, attention should be given to the annular
preventer. Accumulator pressure should be adjusted to maintain constant
closing pressure. Since most respond slowly to the pressure change caused
by a tool joint passing the seal, tool joints should be moved through the
preventer slowly.