Aquaterra Energy has won a major contract to supply subsea high pressure riser (HPR) equipment and services for a subsea abandonment project in the central North Sea.

The multi-million-pound deal will see Aquaterra facilitate the abandonment of ten subsea wells via deployment of a subsea HPR system from a jackup rig. The scope of work could be extended to include two further subsea wells bringing the total number of abandonments to 12.

Riser analysis was completed in-house by Aquaterra and validated by Bureau Veritas. It has confirmed a 50-year return storm operating envelope after HPR and rig optimizations were implemented. This has simplified the project operationally and reduced costs to the operator overall.

Aquaterra’s Initiation Engineering or ‘Well Start’ specialism has been implemented on the project to deliver a one-stop shop for extensive expertise to optimize well activity by taking responsibility for the entire first phase of the well. This approach minimizes third party interfaces across a client’s project and addresses supply and equipment requirements, before the introduction of a blowout preventer. It can also mitigate risk and cut down on costly logistics, capex/opex, the number of crew involved and therefore, helicopter and accommodation needs.

George Morrison, managing director of Aquaterra Energy, said: “Aquaterra has built a successful track record of jackup and subsea high pressure riser operations over recent years using similar systems. The use of jackups can potentially mitigate the heavy loading implications and weather constraints often associated with semisubmersibles in shallow water and thus, extend the operating envelope and productive time through a reduction in waiting on weather.”

With global rates for semisubmersibles averaging around $250,000/day in 2016, day rate rental charges for jackups in Europe and Asia remain considerably cheaper.

Morrison added: “A change in the default mindset is needed to consider jackup drilling units equipped with a HPR for shallow water subsea drilling, completion, intervention and abandonment activities as they can significantly reduce risk and lower operational costs when compared to a semisubmersible completing the same operation.

“Our project history and ‘Well Start’ service has shown that we are more than just an equipment provider but are a trusted turnkey solutions company. We can manage the risk and interfaces associated with jackup subsea conversion packages to ensure it is safely and efficiently carried out. The cost savings, technical benefits and greater operational up time that this translates to, particularly during these challenging times, is key.”

The project is expected to be completed by fourth-quarter 2017.