ESP Pod System With Down-hole Mechanical Isolation Enhances Pump Run-Life in Harsh Wellbore Conditions-A Case Study

Abstract Harsh wellbore environments reduce the run-life of an Electrical Submersible Pump (ESP), adversely affect casing integrity and require expensive ESP replacements that also subject the well to formation damage due to invasion of the kill-fluid used for well-control. Under such severe operating conditions, an ESP pod system coupled with an isolation packer and a fluid loss valve (FLV) can increase the pump run life, reduce downtime and improve well integrity. Pod system is a specially designed capsule to encase the ESP in an enclosed and sealed environment. The Isolation-packer along with the fluid loss valve (FLV) provides mechanical isolation at the sand-face during ESP replacement operations and protects the formation from the invasion of damage inducing kill fluids. During production, the system safeguards the casing from corrosive well fluids and eliminates damage to the power cable from pressure cycles; fluid enters through the bottom of the pod system and is lifted through the tubing without coming in contact with the casing above the packer. This paper describes a case history on the planning, in-house design, completion and post-installation performance of an ESP pod system implemented as a pilot study for a well in Humma field, Wafra Joint Operations –Partitioned zone. A cost effective and case specific solution was achieved by assembling the various ESP pod components together after researching the various vendors available. The objectives of higher production, improved recovery, and reduced lifting costs were achieved since installation, in the last five and a half years of ESP run-life. The pod system proved to be a customized solution for this well which was previously functioning with diminished pump performance and suffered from frequent failures that led to critical well control issues encountered during pump replacement. ESP is a preferred mode of artificial lift in the Humma field to tackle higher production rates from deep reservoirs. The post installation performance of the ESP pod system has laid the guidelines to achieve uninterrupted and commercially viable production from similar reservoirs that have sub-hydrostatic reservoir pressure and hostile downhole operating environments not conducive for a standard ESP installation and operation.