Page 353 - Practical Well Planning and Drilling Manual

Section 3 revised 11/00/bc 1/17/01 12:00 PM Page 329

3.1.8
Well Control [ ]

The complete BOP system should be tested at the following intervals:

After installation of the wellhead and BOP prior to drilling
After 7 days, which may be extended to 14 days depending on the
operations in progress and pending
Prior to drilling into expected hydrocarbon reservoirs or overpres-
sured formations
Prior to a production test
At any time if any doubt arises over the stack integrity, such as
after repairs

The accumulator should be tested at the same time as the BOP
stack. They can be done together by switching off the accumulator
charge pumps and using the stored energy to operate the BOPs while
carrying out the pressure test. In addition, the accumulator should be
tested after repairs have been made to the system, such as bottles, blad-
ders, pumps, etc.
The accumulator bottles precharge pressure shall be checked prior
to drilling out cement in the casing shoe. Unless otherwise specified
the precharge pressure for a 3000 psi system shall be 1000 psi.
After nippling up, the wellhead and BOPs should be subjected to a
500 psi pressure test followed by a high-pressure test to the lower of
rated BOP or wellhead/casing pressure. Subsequent pressure tests are to
the maximum anticipated wellhead pressure, with a maximum on the
annulars of 70% of working pressure. Kill and choke lines and mani-
folds are tested to the lesser of ram or manifold working pressure, but
no tests shall be made against closed chokes. Kelly/TDS and kelly cocks
are tested to their rated pressure. Test pressures in each case are to be
held for at least 10 minutes; this implies that if the pressure drops ini-
tially then settles down (air in system), then it can be repressured and
held. However, a steady drop indicates a leak that must be investigated
and fixed.
The suggested BOP test procedure below shows a suggested
method of testing a 3-ram surface stack, where the test pressures are
the same as the casing test pressure. Kill and choke manifolds, kelly
and stab-in valves may be tested during tripping or other operations to
save time, so long as the normal shut-in procedure can be used in the
event of a trip drill or kick.

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