ABERDEEN, UK – Aquaterra Energy has a contract to supply subsea high-pressure riser (HPR) equipment for a 10-well subsea abandonment program in the UK central North Sea.
The subsea HPR system will be deployed from a jackup rig, and the scope of work could be extended to include two further subsea well abandonments. The project should finish during 4Q.
Aquaterra’s in-houseriser analysis, validated by Bureau Veritas, has confirmed a 50-year return storm operating envelope (following HPR and rig optimization measures). This work is said to have simplified operations and reduced costs.
The contractor is implementing its ‘Well Start’ optimization service, taking responsibility for the entire first phase of the campaign.
This, the company says, minimizes third-party interfaces across a client’s project and addresses supply and equipment needs prior to the introduction of a BOP, also limiting risk, logistics costs, capex/opex, the number of crew involved and therefore also helicopter and accommodation needs.
George Morrison, Aquaterra’s managing director, said: “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/d last year, rental charges for jackups in Europe and Asia remain considerably cheaper, the company points out.
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.”