Abstract
Dismantle, Inspection and Failure Analysis (DIFA) of Electrical Submersible Pumps (ESP) has driven operating companies as one of their key improvement factors for ESP run life. In this paper, an improved process and lessons learned of DIFA over 25 years will be presented.
Establishing failure mode, as per API RP 11S1 guideline, ensures the ESP DIFA is conducted in a structured and methodical manner. Generally, during DIFA three key pieces of information are considered, i.e., the failed item(s), failure mechanism and finally the failure root cause or causes. In addition, the history of the equipment installed, the well data, the completion geometry and any surface or downhole constrains are also used as very important part of the data needed for the DIFA of each well.
The improved process is not only applicable for the primary failed component mode but extends to the expected second or third components and also considers their failure modes even if the equipment survived the current failure. A comparison of the ESP technologies, in terms of failure mode and run life has been conducted. Individual component failure with respect to other technology alternatives is compared to derive a relative advantage achievable in run life of the system. Such comparison is saved in a database for equipment selection criterion which can be used as a tool during the initial design phase of other ESP systems that will be implemented in various environments, either mild or harsh. A relative comparison is shown with the same component completion in different location with similar environment. A DIFA alert process with lessons learned and recommendations has been established in order to communicate with all different parties involved or affecting the ESP lifecycle.
This technical approach keeps all organizations focused on maximizing ESP reliability while promoting motivation and a competitive environment for ESP vendors to do its best. The result is a reduction in failure rate and improved ESP run life which directly benefit the economics of both ongoing and new artificial lift projects.
