Wellhead Penetrator Problems and Best Practices in ESP Thermal – SAGD Applications

Abstract

Abstract Wellhead penetrators are a critical component in the ESP electrical system. The harsh SAGD environment and conditions impose an even higher level of stress on penetrators (high temperature, H2S, water vapor production). Recently, a sudden increase in wellhead penetrator failures in the Surmont SAGD ESP operation, near Fort McMurray, Canada, lead to an enhanced field-wide root cause analysis (RCA) effort. This paper is a field-case study that describes the findings of this RCA and the mitigation measures taken. Among the actions taken, a feasibility study was fast-tracked to determine the potential for success of the Time Domain Reflectometry (TDR) method to discriminate if what was perceived as a potential "downhole electrical failure" was indeed a much shallower penetrator failure. Being able to identify a penetrator failure can yield significant savings in rig-time and workover efficiency while avoiding unnecessary transportation and replacement of non-failed downhole equipment such as the ESP and cable. TDR usage is common in other industries, but their use in ESP operations has been limited to expensive and complex systems such as offshore or deep installations. An ensuing field-wide trial was promptly commissioned in order to validate the effectiveness of the TDR method. In a complex environment, the importance of an empirical study with real-world conditions is critical to determining success. This paper describes the basic principle of the TDR method, and focuses on the TDR signal interpretation experience gained in Surmont in 43 failures as of May 2020, during the field-wide trial. Results presented are promising and support the accuracy of this method to detect failure location. While the TDR readings were implemented under challenging SAGD conditions, authors believe that its implementation could be considered in most, if not all ESP installations. The paper will also describe any challenges and limitations that have been discovered.