The offshore industry is currently in the middle of an ongoing process of reducing its carbon footprint for subsea production systems while expanding into the market of large-scale injection of carbon dioxide into subsea wells.
This paper outlines a systematic low-risk approach for incorporating battery-powered all-electric subsea trees into existing subsea production systems, providing significant reduction in CO2 emissions for today’s applications and laying the groundwork for low-cost carbon-capture-and-storage (CCS) subsea trees and field architectures. By using battery-powered all electric subsea trees for brownfields, it will be possible to tap into existing conventional electrohydraulic subsea infrastructures with minimal impact to the existing topside and subsea systems. This will significantly increase the technology readiness level (TRL) and at the same time serve as an enabler for a seamless introduction of this technology for CCS applications. These developments will likely involve very long tiebacks and layouts different from the ones commonly found today. However, electric technologies are a perfect fit for this application.
There are two major technologies that can support that successful journey. First are the battery systems, which will provide “trickle-charge” functionality. This will help keep the power demand of the distribution system to a minimum, enabling the utilization of simplified umbilical and distribution systems. The second element includes a suite of electric actuators that are highly configurable in terms of their actions, power requirements, and communication interfaces.
This provides a high degree of flexibility for today’s applications and the challenges of the future to come.