A potentially cost-effective, efficient means to develop remote oil & gas fields
Subsea tieback projects are transforming the offshore oil and gas industry by enabling efficient extraction from remote fields and satellite reservoirs, an approach aiming to significantly reduce capital, expenditure, environmental impact, and time-to-market compared to traditional offshore platforms. According to many analysts, subsea tieback projects are set to play an increasingly critical role in the future of offshore oil and gas production.
As of June 2024, the trend towards subsea tiebacks was accelerating, with a number of newly announced subsea tiebacks joining those already in advanced stages of development. Many companies are exploring collaborative development and shared infrastructure models to further drive down costs.
Subsea Tieback Projects Across the Globe
In the North Sea, one of the most notable subsea tieback projects is the Cambo field development, operated by Ithaca Energy, which acquired Shell’s remaining 30% stake in the project back in November 2023, making it the sole owner of the project.
This was followed by Ithaca Energy’s agreement with Eni, in April 2024, for the combination of assets, creating a major independent oil and gas company on the UK Continental Shelf (UKCS).
Located west of the Shetland Islands, the project involves a subsea tieback to an existing floating production storage and offloading (FPSO) unit Sevan. The Cambo field is projected to commence production by late 2024 and is expected to achieve a peak output of 170,000 barrels per day.
Subsea 7 is responsible for the engineering, procurement, construction, and installation (EPCI) of subsea infrastructure, including manifolds and flowlines, while TechnipFMC is supplying subsea trees and control systems to ensure efficient production.
TechnipFMC’s latest subsea trees are designed to handle high-pressure, high-temperature environments, critical for the challenging conditions in the North Sea, while Subsea 7’s flexible flowlines, installed in early 2024, are optimized for long-distance tiebacks and capable of handling multiphase flow, ensuring reliable hydrocarbon transportation to the FPSO.
In West Africa, BP’s developing the Greater Tortue Ahmeyim (GTA) project involves a 120-km subsea tieback to a nearshore LNG facility. Scheduled to deliver first gas by late 2024, this project is pivotal for gas export and energy supply in the region. TechnipFMC is providing subsea production systems and flexible flowlines, while OneSubsea has been hired to provide subsea boosting systems and control umbilicals.
TechnipFMC’s flexible flowlines and production systems, installed in mid-2023, are designed to handle large volumes of gas over extended distances. These systems are critical for the project's efficiency and were chosen for their reliability in deepwater conditions. SLB’s OneSubsea division provided boosting systems and control umbilicals in early 2024, ensuring effective gas transport and system integrity.
In Asia Pacific, the Ichthys LNG project, operated by INPEX, is undergoing a significant expansion with new subsea tiebacks planned for 2024 and 2025. This expansion aims to increase the LNG production capacity by tying back new gas wells to existing subsea infrastructure.
Subsea 7 is managing the EPCI of the subsea systems and pipelines, while Aker Solutions is providing subsea production systems and control equipment.
Subsea 7’s involvement includes the installation of advanced flowlines capable of handling high-pressure gas transport. These systems were put in place in early 2024 and are designed to minimize hydrate formation and maximize production efficiency. Aker Solutions’ subsea production systems, installed in mid-2023, feature integrated control systems that enhance operational efficiency and reduce downtime.
Photo Credit Onesubsea
Supply Chain and Technological Advances
Technological advancements in the subsea tiebacks area of oil and gas developments are also picking up pace, promising to deliver cost-effective and sustainable solutions, with most notable steps being made in subsea processing systems, enhanced flow assurance technologies, subsea robotics as well as digital technologies.
Subsea processing systems are transforming subsea tiebacks by allowing hydrocarbon processing directly on the seabed. Notable advancements include subsea separators, pumps, and compressors, like the ones supplied by OneSubsea for Shell's Whale field and BP's GTA projects, which is said to offer subsea boosting systems that enhance production efficiency and allow for longer tieback distances using multiphase pumps and compressors.
Flow assurance technologies are critical for maintaining continuous flow in subsea tiebacks, especially in deepwater and long-distance scenarios. Baker Hughes provides advanced flow assurance solutions, such as electrically heated pipelines and advanced chemical injection systems, which mitigate issues like hydrate formation and wax deposition. These technologies are integral in projects like LLOG's Shenandoah field and Shell's Whale field, ensuring reliable hydrocarbon flow from subsea wells to processing facilities.
Digital twins and remote monitoring technologies are also revolutionizing the management of subsea tiebacks. Digital twins create a virtual replica of subsea infrastructure, enabling real-time monitoring and predictive maintenance. Siemens and ABB are leaders in this area, providing digital twin solutions that enhance operational efficiency and predictive maintenance capabilities. Their technologies are deployed in projects such as the Johan Sverdrup field in the North Sea, allowing operators to optimize production and preemptively address potential issues.
Future Outlook
Subsea tiebacks offer significant financial advantages by leveraging existing infrastructure, which reduces the need for new platforms and extensive surface facilities. This approach cuts capital expenditures (CAPEX) and operational expenditures (OPEX), enabling companies to bring new fields online faster and more cost-effectively. The integration of advanced subsea technologies also improves production efficiency and reduces maintenance costs, further enhancing the economic viability of offshore projects.
The offshore oil and gas industry is increasingly adopting low-carbon strategies, with subsea tiebacks playing a crucial role in minimizing environmental impact. By using existing infrastructure, subsea tiebacks reduce the need for new platforms and lower greenhouse gas emissions. Projects like Shell's Whale field and BP's GTA are integrating renewable energy sources to further reduce their carbon footprints.
As of June 2024, a number of projects are progressing globally, supported by advancements in technology and a focus on sustainability, with the new projects such as Shell's Dover field in the Gulf of Mexico and Equinor’s Irpa field in the Norwegian Sea announced, further cementing the trend towards efficient, low-impact extraction methods.
Also, the OneSubsea joint venture and Subsea7 secured the EPCI contract from Norwegian oil and gas company OKEA to develop the Bestla project (formerly known as Brasse) in the North Sea, offshore Norway. Specifically, the companies were selected to accelerate the subsea tieback delivery to aging platforms, comprising a two-well project, with a 13-km tieback to the Brage platform.