API RP 11S9-ed.1

Die Annotation des Normtextes API RP 11S9-ed.1 :

API RP 11S9, 1st Edition, March 2023 - Permanent Magnet Motor Safety

This document serves to emphasize safety aspects and recommended practices concerning the handling, installation, trouble shooting, operation, and pulling of permanent magnet motors (PMMs) used in subsurface and surface artificial lift pumping systems.

This document does not replace any other specific safety documentation; national and/or local electrical regulations take precedence.

Subsurface systems entail the motor located downhole with the pump. Centrifugal pumps are historically called an electrical submersible pump (ESP). A progressing cavity pump (PCP) mated with a downhole motor with or without a gear reduction unit is typically called an electrical submersible PCP.

For this recommended practice, Figure 2 will be used as reference for a high-voltage conventional ESP system. The submersible system may have a pump that is centrifugal (default), co-helical axial, progressing cavity, gear, vane, or other type of rotational pump. The motor will be of rotational nature to drive the aforementioned pumps and of permanent magnet design.

There are many types of equipment configurations available for PMM operations. Configurations included in this document are listed in Table 1.

Each of these system configurations will have various considerations that shall be made to ensure personnel safety. Some are common to all PMM operations, whereas others will be unique to the given configuration.

— Surface pumping deployments have limited exposure to electrical hazards because the motor is at surface and its shaft or linkage to the pump system can be locked.

— Some deployments install the pump after the motor, and so unplanned motor rotation does not occur when tripping the motor.

In the case of linear submersible pumps, the pump is reciprocating (vertical motion) and is driven by a linear PMM comprising an armature and permanent magnet translator. The armature is the equivalent to the stator, and the translator is the equivalent to the rotor of a conventional ESP. Downhole linear PMM systems are not expressly included in this document as the force required from the fluid to lift the motor and pump is unlikely to result in motor voltage. However, the supplier should be consulted and the principles in this document applied.

After an introductory review of the nature of risks potentially arising from the use of PMMs (see Nature of Risks and Approach to Safety), this document addresses the main operational tasks involved as laid in the table of contents and shown in Figure 3. The annexes provide detailed supporting information.