Recommended Solutions for ESP Installed in Very High Salinity Reservoirs and Severe Corrosive Media

Abstract

Abstract An experience of ESP issues troubleshooting to overcome high corrosion media of GSA wells is presented. Likewise, actions taken to extend run life of pumps are explained. GSA is the unique company in Algeria adopted ESP system including all services, there was no chance to share experience with other entities in Country. Thus, it became necessary to try all available approaches during a journey of 10 years to mitigate ESP failures and eventually production downtime. To overcome high salinity of >320 g/l, several actions were introduced in either ways, ESP equipment or well completion. Simple motors and protectors changed to tandem to prevent water penetration inside motor. Power cable was changed from Galvanized to Monel Armor for high corrosiveness. Completion wise, one or double 1/2" water dilution lines were adopted, run along tubing, connected to tail pipe which run to perforations. Modification in completion metallurgy took place also, when Carbon steel replaced by Super 13Cr instead. Supplementary actions taken at surface, pressure switch was connected with VSD to smoothly shutdown ESP for unforeseen SCSSV closures. The adopted actions yielded considerable positive results. ESP failures originated from water penetration inside motor was reduced to 20%. Whereas, salt deposition blocs were almost prevented and resulted decrement in bullheading and coiled tubing interventions by 85%, except for some wells when salt bloc build-up is occasionally quicker and more important than water dilution rate. Running 1/2" injection line along with tail pipe led to less ESP shutdowns frequency. Changing the power cable type gave roughly good results as well. Once running Monel Armor, number of power cable failure related decreased and consequently contributed in reduction of whole failures. Saying that because power cable failure related represented 70% of ESP failures in 2015. Considering Super 13Cr instead of Carbon steel tubing gave positive indications and reduced sharply tubing integrity failure related. The problem still exists, however, with very low frequency. For surface equipment, all unforeseen SCSSV closure, actuated from control panel is always accompanied with gradual decrement of frequency and consequently smoother ESP shutdown. As our organisation is the truly company that uses ESP with a proper sense in Algeria, This paper presents some best practices to be considered for other companies and ESP contractors based in the country or abroad that intend to both install ESP system in very high salinity and corrosive fields and adopt lease model for downhole Equipment.