Demonstration of Advanced Magnetic Technologies for a Highly Reliable and Retrievable Electric Submersible Pump Topology

Abstract

This effort designs, builds and tests key enabling technology components of the magnetic drive system (MDS) electric submersible pump (ESP) concept, an advanced high speed ESP that differs from conventional ESP topologies in using magnetic technologies to increase reliability and retrievability. The enabling components include a radial passive magnetic bearing (PMB) system, allowing for a contact-less bearing system and remote removal of rotating components, and magnetic vibration sensors (MVS), enabling prognostics for higher reliability. An MDS ESP preliminary design has been developed through a DeepStar program, from which the size and integration requirements of the PMB and MVS have been defined. These requirements guide the analysis, design and testing of the full-scale components. Empirical analysis tools are used for initial iterations in size and performance of the PMB and MVS, followed by detailed magnetic finite element analysis (FEA) using commercial validated tools for the final performance prediction. With analytical validation of performance, detail designs are developed and hardware fabricated. Hardware testing is done to validate performance predictions and alignment with system requirements. The PMB performance results include testing of stiffness capability. These characteristics are used to validate the integration requirements for load capability and deflection during static load events, all in relation to validating performance for use in the MDS system. This test data is used to validate the analysis approach used as well as to finalize the integration size of the PMB to meet the performance requirements of the MDS system. To identify rotor operating speed and rotor vibration magnitude and frequencies, the MVS is tested for sensing rotor motion rate and frequency, including sub-synchronous and super synchronous frequencies. Identifying data reduction needs, i.e. how data is compiled and presented to focus on specific areas of interest, is also critical to determine the vibration characteristic of specific events happening in the ESP, such as bearing wear or dynamic fluid changes. Testing also includes variations in tubing materials to assess performance impact. These technologies offer bearing and sensor technologies that enhance ESP reliability and active performance monitoring. The PMBs offer a contact-less bearing system that does not require lubrication, can operate with large clearances to allow free fluid flow, and has no operating life limits. The compact MVS offers rotor vibration diagnostics throughout the ESP, including between pump stages, for monitoring performance, detecting ESP mechanical issues or process fluid variations allowing immediately response to increase operational life.