Deviated well and abrasive environment hindered PCP operation
An operator in the Middle East installed a third-party PCP in one well
at a depth of 1,000 m [3,280 ft]. However, the high deviation (45° at the
pump), dogleg severities greater than 5°/30 m [5°/98 ft], and significant
rate of sand production caused rod failure in less than 3 months. The
equipment was pulled out and a new PCP was run in using a continuous
rod and rod guides, but system run life was again limited to 90 days. The
cost of a workover rig, new PCP equipment, sucker rod inspection and
replacement, and deferred production made the frequent changeouts
unsustainable. A more durable PCP solution was required; sand
production ruled out use of an ESP or sucker rod pump.
Rodless system was unaffected by well profile
The operator chose the KUDU ESPCP PMM, which enables pump
installation in wells with high dogleg severity (DLS) or inclination while
significantly increasing uptime. With no rodstring, torque reduces by
20%–60%, efficiency and safety increase, and power consumption
and opex decrease.
The technology delivers constant and high torque across the full PCP
speed range of 50 to 500 rpm. This flexibility enables accommodating
a wide range of production rates without replacing the pump, which
simplifies artificial lift planning and reduces capex and opex. The system
is preferable to a conventional ESPCP, which uses an ESP motor with
a much higher rotational speed. Because a PCP turns more slowly, the
conventional ESPCP requires a gear reducer downhole, increasing the
likelihood of mechanical problems due to sand production.
The PMM improves efficiency with low power loss in the rotor
and enhances dynamic performance with a variable frequency
drive specifically designed for PMMs. Downhole telemetry is used
to prevent pumpoff conditions, monitor equipment performance,
and optimize well production.