Development and Field Test of an Electric-Submersible-Pump Reliable-Power-Delivery System

Abstract

Summary In high hydrogen sulfide (H2S) and high-pressure/high-temperature fields, the average run life of electric submersible pumps (ESPs) is limited to 3 years. Dismantle/inspection/failure-analysis (DIFA) results show that approximately 50% of ESP failures are directly or indirectly related to electrical-delivery problems concentrated approximately 200 ft in between the packer and the motor. This paper presents a collaborative research-and-development effort to develop and trial test a reliable-power-delivery system (RPDS) with the goal of extending the average ESP run life from the current 3 years to 10 years. The development focuses on improving reliabilities of key power-delivery components including packer penetrator, motor-lead-extension (MLE) cable, and cable connection to the motor. The design integrates learnings from advanced completion and subsea technology, and includes new concepts, features, and materials. Field-pressure-testable connections are implemented to ensure proper field-connections makeup. Factory testing incorporated a robust highly-accelerated-life-test (HALT) methodology to simulate a 10-year service life. Prototype components were designed, fabricated, and tested. These components were integrated and subjected to a rigorous system-integration test. After the comprehensive factory tests, a field-prototype system was built and installed in an offshore well. The system has been operated and exceeds the trial-test success criterion of a minimum 180-day run life. For years, ESP reliability has been a constant issue faced by the industry, with electrical problems at the center of many failure causes. This paper presents a completely new design approach to address this critical challenge. Field installation and testing show the potential of extended run life with this new power-delivery technology.