Improving Run Life of Coiled-Tubing-Deployed ESP in Harsh Environment for Qatar's Al Karkara Field

Abstract

Alternative deployed ESP Systems are strings that are deployed in the well on other than conventional tubulars. Coiled Tubing (CT) deployed Electric Submersible Pumps is one of the most common configurations and has been used successfully in Al Karkara field to reduce intervention cost. As part of a closed loop product improvement workflow, utilizing data from dismantle, inspection and failure analysis of equipment, design improvement were suggested and implemented to address root causes and maximize life in Al Karkara. As part of this work, the main challenges of the application as well as weaknesses identified on the different sections of the string are explained in detail. Moreover, the design and specification changes incorporated because of said observations are also covered, including improvements on the power cable, lower connector, multisensor, motor, bottom intake, and base protectors, among others. Through implementation of downhole equipment ESP upgrade and enhancing the operating philosophy, this improved the run life of Al Karkara field by more than 300%. With the industry shifting into a drastic reduction of total cost of ownership (TCO) approach and with the volatility of oil price, the rigless ESP deployment through coil tubing will help to eliminate the cost of a work over rig while reducing the deferred oil production. This paper showcases the ESP capabilities in this corrosive and high temperature environment.