Shrouded ESP with Y-tool Enables Virtually Unlimited Access to Completion Interval for Well Intervention and Surveillance Operations

Abstract

Deviated wellbores are more common-place in the industry in recent years as Maximum Reservoir Contact (MRC) is the preferred strategy in wellbore construction. These high-angle, tortuous wellbores, however, have now limited the artificial lift options to Electric Submersible Pumping systems which are capable of sustained life cycles in high-watercut, low-pressure, and/or low-rate completions. Production logging and Coiled Tubing intervention in multi-layered completions and/or multi-compartment horizontal laterals equipped with Electrical Submersible Pumping systems has customarily been a major challenge, especially when the bypass fluid velocities are below the motor-cooling threshold for a conventional Y-tool configuration.An innovative design comprising of a shrouded Electric Submersible Pump with Y-tool combination is able to facilitate access to any completion that requires production logging and/or CT intervention. At relatively low fluid rates, the shroud over the Electric Submersible Pump increases the fluid bypass velocity alongside the submersible motor for the required cooling. This shrouded Electric Submersible Pump configuration is conventionally used where the production flow rates within the wellbore are insufficient to generate the fluid bypass velocities necessary for optimum motor cooling. The Y-tool in other completions allows access for any type of wireline or Coiled Tubing-conveyed intervention for surveillance and and/or treatment operations. Previously, if a completion required a shrouded ESP, conventional Y-tools were precluded, due to the limitation of the production casing inner diameter. A specialty Y-tool was designed to accommodate conventional bypass tubing that has sufficient internal clearance for standard wireline tools together with a crossover adapter for the ESP shroud.This combination of conventional bypass tubing and Electric Submersible Pump shroud in the same wellbore, is limited to 9 5 ⁄8Љ casing where the shroud outer diameter and the bypass pipe outer diameter must have sufficient clearance between each other and sufficient stand-off from the inner diameter of the production casing. The Electric Submersible Pump shroud ensures optimum motor cooling and extended system run life, especially at lower flow rates.This innovative technology is now scheduled to be standard equipment in all Electric Submersible Pump completions in production casings with Outer Diameter equal to or greater than 9 5 ⁄8Љ. Diagnostic wireline and Coiled Tubing-conveyed surveys, remedial and stimulation treatments can now be performed thru-tubing in Electric Submersible Pump completions without costly rig workovers. The availability of these services affords timely intervention to arrest increasing watercuts in Waterflood offtake producers thereby reducing the overall baseline production decline rate.