The escalating challenge of well abandonment is becoming increasingly evident, especially in seasoned offshore regions. According to Offshore Network’s recent Global Offshore Decommissioning & Abandonment Report, 180 wells will cease production by 2030 in the North Sea, 7,000 wells require decommissioning by 2030 across Asia Pacific (APAC), and there are more than 14,000 unplugged non-producing wells in the Gulf of Mexico (GOM).
The decommissioning process is not only a matter of regulatory compliance but also carries significant environmental implications and costs. Plugging and abandonment (P&A) costs account for roughly 45% of the total decommissioning cost.
Basins around the globe are actively looking for ways to reduce cost, reduce emissions and enhance the efficiency of their well decommissioning programmes. For example, the North Sea Transition Authority (NSTA) has mandated targets for the UKCS, aiming for a 10% cost reduction in well decommissioning by the end of 2028. Additionally, there is an expectation for industry to achieve a minimum of 50% reduction in emissions by 2030.
Well P&A is shifting from a one-time end-of-life cost to an essential and prolonged effort to reduce emissions. New materials and solutions are required to plug back wellbores for eternity. But what does eternity mean?
Until now, eternity has been used as an industry-wide metaphor, emphasizing the need for long-term durability and effectiveness of the sealing process. Historically, cement plugs have been the primary method used to create ‘permanent’ barriers within the wellbore.
Cementing to plug offshore oil and gas wells has been used since the late 19th century, and while effective, invites several disadvantages, mainly surrounding cost, regulatory compliance and environmental concerns. As a result of hydration and shrinkage, casing movement and chemical reactions, cement plugs are developing cracks leading to instances of leakage. The same can be said for mechanical plugs, or the cut and cap method, which present complexities for installation, limited flexibility and further environmental concerns.
As technology, and concurrently, regulatory requirements evolve, the permanence of existing long-standing solutions comes into question. Innovating in this space is multi-faceted; from identifying effective barriers, to verification and long-term risk management, there are several considerations to be made when addressing technology gaps. Identifying novel solutions is key, yet further development, trialing and testing, and eventual adoption is slow burning.
At the Net Zero Technology Centre (NZTC), with active support from the NSTA, Technology Leadership Board and Offshore Energies UK, we are facilitating industry collaborations through our Well Decommissioning Collaboration initiative. The multi-operator consortium has already provided a range of technology developers with support in developing, validating results and qualifying their technology, faster than they would have independently.
For instance, Aberdeen-based Deep Casing Tools (DCT), a company to have benefited from this sort of collaboration, is developing its Rubblizer technology for more efficient and cost-effective casing recovery. DCT has forecast that 3000MT of CO2 emissions will be saved per project.
Additionally, Sentinel Subsea, also based in Aberdeen, has developed a long-term remote subsea gas-leak monitoring solution, operating without the need for active power or data communication, lowering risk, costs and the carbon footprint associated with manual inspection methods.
Both of these companies have now commercialised, after just few years of development, and are actively driving emission reduction by enabling affordable and sustainable P&A. What these projects share in common is collaboration, having received support from NZTC and operators to maximise their full potential and propel the journey to deployment.
Wellstrøm, a Stravanger-based company specializing in sealing technologies, has combined forces with leading operator Total Energies. As members of NZTC’s Well Decommissioning Collaboration consortium, they fast-tracked their solution resulting in an industry first; a rigless, electrically powered and real-time monitored alloy plug. The technology has successfully been deployed onshore, and is set to be deployed offshore later this year.
The technology delivers a superior quality and highly durable wellbore barrier with the potential to provide reliable sealing for thousands of years, and the installation operation itself reduces CO2 emissions compared to conventional methods.
NZTC, in partnership with the ‘Go Radical P&A Project’ managed by Energy Transition Norway, The Danish Offshore Technology Centre, Petroleum Technology Alliance Canada and The Centre for Decommissioning Australia, is currently calling for solutions similar to that of Wellstrøm’s, seeking innovations that can enable rigless P&A. Successful applicants will have the potential to join our collaborative initiative for support in developing, trialing and testing their solutions, gaining exposure to world-leading operators ConocoPhillips, Petrobras, Harbour Energy, Respol and Total Energies.
The UKCS is far from its end game, but by embracing disruptive technologies, key collaborations could emerge to take industry closer to its targets. For well P&A, eternity could last a lot longer.
