Aquaterra Energy, an offshore engineering solutions provider, has won a multi-million-pound contract to supply subsea high-pressure riser (HPR) equipment and services for an abandonment project in the central North Sea.
Aquaterra said on Monday that it would facilitate the abandonment of ten subsea wells via deployment of a subsea HPR system from a jack-up rig.
The company added that 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 confirmed a 50-year return storm operating envelope after HPR and rig optimizations were implemented.
George Morrison, managing director of Aquaterra Energy, said: “Aquaterra has built a successful track record of jack-up and subsea high-pressure riser operations over recent years using similar systems. The use of jack-ups can potentially mitigate the heavy loading implications, and weather constraints often associated with semi-submersibles in shallow water and thus, extend the operating envelope and productive time through a reduction in waiting on weather.”
Aquaterra said that the rates for semi-submersibles averaged around $250,000 per day in 2016 while day rate rental charges for jack-ups in Europe and Asia remain considerably cheaper.
Morrison added: “A change in the default mindset is needed to consider jack-up drilling units equipped with an 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 semi-submersible completing the same operation.”
According to Aquaterra, the project is expected to be completed by the fourth quarter of 2017.