Traditional electric submersible pump (ESP) systems have drawbacks in terms of installation speed and efficiency. To overcome these obstacles, some alternatively deployed ESP systems, including the one selected, are deployed into the production tubing, subjecting the system to the properties of the produced fluids. A novel rigless-deployed ESP system developed for use in high hydrogen sulfide (H2S)/high chloride production environment is a solution.
An initial step reviewed and ranked competing alternate deployment ESP technologies available in industry along with several new concepts. A new approach to alternate deployment technology was selected. Rigorous testing was conducted to qualify the selected technology and materials for harsh production environments. Testing included a modified NACE TM0175 test due to the processing of the power cable design. Integration testing was performed in a test well to validate the integrity and deployment of the new system prior to field deployment of the rigless-deployed ESP system.
The cable deployed ESP (CD ESP) employs a fit-for-purpose power cable that incorporates an exterior metal jacket, providing strength to deploy ESPs thousands of feet into the well. The TransCoil system's power cable outside diameter is roughly 40% smaller than current 2-3/8-in cable-internal, coiled-tubing (CICT) systems; therefore, it is lighter in weight and reduces tubing pressure losses compared to previous products. Product reliability is enhanced as the power cable is fabricated in a continuous manufacturing and inspection process on a factory floor. The tightly controlled manufacturing process significantly improves the product quality over CT cable systems. The power cable can be fabricated from different metallurgies ranging from carbon steel to nickel allow based on the well requirements. A nickel alloy power cable laboratory qualified to 15% H2S and 150,000 ppm chlorides was field deployed in an onshore well and demonstrated an installation time reduction of nearly 50% over rig-deployed systems.
A power cable rigless-deployed ESP system solves many of the challenges that currently plague the industry including operational efficiency, rapid replacement, and product reliability in wells in harsh environments worldwide. The power cable rigless-deployed ESP system has, in particular, the opportunity to transform ESP replacement in offshore wells.