Is it necessary to install a downhole safety valve in a subsea ... - NTNU

Is it necessary to install a downhole safety valve in a subsea oil/gas well?
30 11 LESS The pressure is low The BOP is leaking Acceptable leakage must be
defined prior to operation
31 12 NOT The BOP is not working The operations may be
properly
harder to perform or not able
to be performed
32 12 LESS Fluid is flowing from the
connection
The BOP is leaking
33 13 NOT The BOP is jammed The BOP does not
disconnect
34 14 NOT The riser elevator is The BOP can not be lifted Make sure to have redundant
broken
from the seabed
lifting systems
35 14 MORE The riser/ BOP assembly The BOP can not be lifted Make sure the riser elevator
is to heavy to lift from the seabed
and lifting gear is properly
proportionate for the job
36 15 NO The guidelines are not The BOP may not be moved
able to loosen
away from the seabed
equipment and has to be
raised above the subsea
equipment
37 16 MORE Riser is screwed on to The pipes may not be able to Make sure to have cutting gear
tight
demount
present at the site
38 16 OTHER The roughneck is This may lead to a delay in Make sure the programming of
THAN screwing the pipe the the operation
the iron roughneck is right
opposite direction.
prior to operation
39 16 NO The riser pipe rack is not Operation will be delayed as Make sure the programming of
in the right position or the rack must be moved or is right prior to operation
the pipe handling system the roughneck be re-
is programmed wrong programmed
Diploma thesis, NTNU 2002
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