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the BOP. The male control pods lock and seal in the female
receptacles and are run with the stack. The individual control pods
and hose bundles of a single female system can be retrieved
independently and rerun to the BOP stack with the use of a small
guide frame that is run on two guidelines. To release the riser from
the stack in an emergency situation, the riser connector and both
control pods must be released.
The support equipment for the hydraulic control system
consists of two power-driven hose reels that spool off and rewind
the control hose bundle, a master control panel with hydraulic
pumps and fluid supply reservoirs, and a driller's control panel.
Often a mini-panel is included in the toolpusher's office. The
regulated output pressure from the master panel is usually 1,500
psi with 3,000 psi available.
It is now standard practice to install a rack of accumulator
bottles on the BOP stack to provide a sufficient volume of
hydraulic fluid to operate all functions on the stack. This avoids
the slow reaction time that would result if all the required fluid had
to be transferred through the hose bundle down to the BOP.
The Koomey double female system for BOP control is
comprised of a male control pod connected to the hydraulic control
hose bundle that houses the hydraulically controlled SPM. As in
the single female system, the SPM directs the main hydraulic
power to the various functions on the stack. In the double female
system, the control pod seals and locks in an intermediate female
receptacle bolted to the lower riser package. When the lower riser
package is installed on the BOP stack, the male mated to the
intermediate female receptacle lands and seals in the female
receptacle in the upper frame of the stack.
BOP stacks are always equipped with two control pods for
complete backup hydraulic control. Hydraulic pilot hoses and a
hydraulic supply hose make a bulky package run from the surface
— moreso as water depth increases. For this reason, a number of
manufacturers are now providing elec- trohydraulic control
systems.
With an electrohydraulic control system, electrical power,
fed through a multicore conductor, actuates solenoid-operated
valves in the control pod. Then, only a single hydraulic hose is
required to deliver the hydraulic fluid to the accumulators. Some
systems have incorporated the accumulator fluid supply line into

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