Scale buildup challenges ESP
Scale buildup on ESPs is a common occurrence. The scale builds up on the
motor housing over time, affecting the cooling efficiency of the system and
raising the pressure on the ESP. This often happens with no outward indication
to the operator. If scale continues to build unchecked, threatening events such
as high pressure or motor overheating can occur, in which case the ESP
controller shuts down the well to protect the system.
For a conventional field where surveillance is limited to episodic
production data from test separators, the unnecessary downtime begins as soon
as the ESP shuts down. For these fields, the sole purpose of downhole gauges is
to enable diagnostics of the shutdown cause after the event, when the operator
mobilizes a field crew, downloads sensor data, analyzes the well performance,
and begins remediation. This can last days.
Khalda Petroleum Company could have been faced with these challenges
when one of its artificially lifted wells in the Egyptian West Desert started
to build up scale, if it had not taken one important preventative measure.
Lift IQ service analyzes pump remotely, informs solution
When Khalda Petroleum Company entered the Egyptian West Desert in 2010,
its engineers chose to equip wells with Phoenix xt150 high-temperature ESP
monitoring systems and asked Schlumberger to perform the Lift IQ service. When
scale started to build on an ESP in one of its wells in 2014, the operator had
the right tool to diagnose the situation—before it became a problem. The
Lift IQ service delivers 'round-the-clock remote surveillance of all artificial
lift systems, preventing or resolving ESP downtime, misuse, or failure.
Experienced engineers monitor alarms and analyze data transmitted from multiple
wells across fields simultaneously in real time, up to 24/7/365, at one of many
Schlumberger Artificial Lift Surveillance Centers (ALSCs).
Well production restored swiftly, saves workover costs
The Lift IQ service indicated the rise in intake pressure and motor
temperature in real time, which the ALSC engineers recognized as an early
symptom of scale buildup. The remote monitoring and control system enabled the
ALSC engineers to immediately respond by decreasing the motor loading and
prevent the well from tripping. Schlumberger then took action on-site by
clearing the scale with acid washes injected through coiled tubing directly on
the discharge head of the pump. Without the acid treatment, the motor could
have continued to overheat until failure.
Khalda Petroleum Company saved USD 540,000 in workover costs and
deferred production and avoided unnecessary delays because of the accurate,
real-time measurements taken by the Lift IQ service.
For more details about the well and operation, see SPE 177926.