Securing critical energy supply

As we consume energy by heating homes, turning on the oven or enjoying a hot shower, the gas used to make this possible has travelled hundreds of miles and been thoroughly processed to be delivered safely to your home.

The Scottish Area Gas Evacuation (SAGE) system, located at St Fergus, north of Aberdeen, helps to ensure an ongoing, critical energy supply to the country alongside numerous other gas terminals dotted across the UK. Gas processed at SAGE feeds into the UK’s National Transmission System, providing a significant proportion of the UK’s total gas supply.

Wood is responsible for the day-to-day operation of the SAGE system via an evergreen contract with our client Ancala Midstream Acquisitions Limited (Ancala Midstream). The system transports gas through the 323km SAGE pipeline between the northern part of the Central North Sea to the SAGE terminal, where it is processed on behalf of North Sea gas producers.

The facility is an integrated gas transportation and processing system throughput of around 465 million cubic feet of gas per day: enough power to heat over 3.3 million homes.

Ensuring this critical energy supply to the nation, SAGE has daily production targets to meet. During the four years Wood has been operating the site, these targets have not once been missed. Even throughout the Covid-19 pandemic with reduced manpower and extra safety precautions in place, the site has continued to safeguard the energy demands of homes, hospitals, and other crucial services when we need them the most.

Ensuring longevity

Wood and Ancala Midstream work together as operating partners in an open and collaborative relationship that results in enhanced value for both partners and enables rich decision making. With our continued reliance on hydrocarbons for some decades to come, the partners are keen to ensure longevity of SAGE by working together on a rationalisation project. The project aims to deliver a distinct set of options and activities to position the SAGE plant for a further 20 successful years of production.

Although we are still reliant on hydrocarbons, enabling sustainable operations is vital in the drive towards net-zero. To support the long life of SAGE against the backdrop of the energy transition, Wood is also delivering an energy management plan, investigating and presenting the carbon reduction opportunities available to pursue at the site. This work feeds into the Oil and Gas UK methane working group, of which Wood is a member. This is an industry led initiative to work collaboratively in developing a range of potential carbon reduction solutions, with a target to half industry methane emissions by 2030.

If an issue is identified at SAGE, the team are poised to act to avoid any interruption to production and thus, gas supply. When a minor hydrocarbon emission is detected, the implementation of swift and effective mitigations and monitoring are put into place.

For example, to provide a permanent solution in one such incidence, Wood designed and fabricated a clamp to be fixed to an insulated joint ensuring it was fully sealed, made possible by early detection and working directly with the client team.

Due to the challenging nature of the issue, the engineering team were able to provide a technical-based solution which resulted in a truly unique design and specification to create the clamp. The size and scale of the clamp, weighing 16 tonnes, is believed to be the largest non-subsea related clamp installed by Wood and their contractor.

The clamp was safely and successfully installed and is now a life-of-field repair that will be in place for around 25 years.

Sustainable operations

Wood is committed to reducing its carbon emissions by 40% by 2030. As Wood manages the day-to-day operation of SAGE, it also purchases the electricity to power the site. Reviewing the electricity procurement strategy and adopting cleaner power generation by switching to a renewable tariff is one step towards Wood’s carbon reduction goal.

As of the second quarter of 2021, the electricity used to power SAGE is now generated entirely by wind and hydro, which means the carbon emissions associated with powering the site have radically reduced.