Power to an electric submersible pump (ESP) is delivered from surface to the downhole electric motor via a specially constructed three-phase electrical cable that is strapped outside of the production tubing. This cable is designed specifically for downhole well environments and power requirements.
Why Is It Important to Have a Reliable Power Distribution for ESP Applications?
Reliability of power distribution, cables, connectors and accessories for ESP applications is a key objective for achieving the desired well production uptime, at reduced well intervention costs. Some statistics show that about 15% of the world ESP failures are related to failures in power delivery. For some sour applications (high H2S) or severe service applications this can be as high as 50%.
What Are the Elements of a Power Delivery System?
Apart from the surface system, power to the ESP is transmitted downhole through a cable (may include splices), connectors, wellhead and packer penetrators (also providing pressure isolation). These elements are selected according to the working environment and requirement, and from guidelines provided by manufacturers.
Surface Connector, Wellhead Penetrator, Lower Connectors and Packer Penetrators
Manufactured to various surface and well requirements and operating norms, are available in various sizes and shapes and connect the electric power through wellhead and production packers.
Cables are selected according with the application and well conditions, including temperature, pressure, well fluid (corrosive, gas presence, etc.), and are available in a wide range of conductor sizes or gauges with configurations either round or flat, using several different insulation and metal armor materials for different well environments (refer to API RP11S5 and RP11S6 for design, application, and testing of ESP power cables).
Power cables are spliced through unwinding a short length of the armor strip along each cable portion, splicing the conductors in a manner well known to the art as by soldering, and then vulcanizing the end of the round cable portion insulation, thus forming a continuous, integral insulating jacket, preventing the migration of fluids along the interstices which would otherwise be formed.
Downhole Motor End Connector
Also referred as MLE (motor lead extension) or PLE (power lead extension), are specially spliced to the lower end of the power cable and termination by plugging or splicing into the motor electrical connection.
What Should You Look for When Choosing a Power Delivery System?
The almost century-old power distribution configuration is now evolving, targeting a high system performance and reliability while drastically reducing well production downtime and intervention costs.
The AccessESP power delivery system offers a safer and highly reliable encapsulated cable, spliceless and pressure balanced connections, from the surface power source, through a wellhead and packer to the downhole electric submersible motor.
We are a team of experts partnering with other experts to develop innovative ESP technologies to increase your uptime. Contact us today to learn more about how our system can increase your well’s economic life.