Page 152 - Well Control for Completions and Interventions

144 Well Control for Completions and Interventions

Annular preventer

Pipe ram
Shearing blind ram

Upper kill line Upper choke line

Pipe ram
Pipe ram or VBR
Lower kill line Lower choke line

Wellhead

Figure 4.4 Example configuration for a blow out preventer stack with four ram
preventers.

4. Annular preventer and four ram preventers
Many operating companies have a policy of using four ram preven-
ters on high-pressure wells (,10,000 psi) and hazardous wells (H 2 S).
Having one more rams than the API minimum recommendation has
several advantages:
• Two pipe rams allow ram-to-ram stripping with the third ram used
as a safety ram.
• Allows two-ram sizes when running a tapered completions string.
A VBR in the position provides back-up for both pipe rams.
A typical configuration is to position a drilling spool between two
double ram blocks with the rams equipped (bottom up) with pipe (or
VBR), pipe, shear/blind, and pipe (Fig. 4.4).

4.3 ROUTINE TESTING OF BLOW OUT PREVENTION
EQUIPMENT

Blow out prevention equipment is emergency equipment and must
be maintained in proper working order. A strict regime of routine