WIRELINE Spring 2017

Subsea Developments | Efficiency

These standardisation themes were then applied to four existing UKCS subsea projects to investigate how they could have delivered savings and improved efficiency vis a vis existing bespoke working practices. Guy explains: “These were typical subsea developments such as an FPSO (floating, production, storage and oloading vessel) riser system; two subsea pipeline tie-backs connecting the fields to host platforms; and a subsea manifold and bundles pipeline system that connects multiple subsea wells.” “When taken together, the results showed many opportunities for improving project delivery, with the potential to deliver savings between 15 to nearly 30 per cent,” outlines Steve. Applying the same principles, an exercise was carried out to further demonstrate the impact of industry’s bespoke ‘preferential requirements’ on cost and schedule. Across 16 scopes of a subsea development, a reference case (a simplified and fit-for-purpose approach) was scored against nine of the operators’ preferential requirements. Steve adds: “The results of this ‘strawmen exercise’ were very powerful and clearly highlighted how the current approach contributes to higher costs and longer project schedules.” He continues: “However, the overall savings and weighting of each of the standardisation themes will vary from

project to project, by the cultures and behaviours adopted and the perception of risk. Therefore, how a company approaches and adopts the principles into their own practices will be crucial. Early engagement with the supply chain is important.” Prospects for Pegasus The next step was to apply the findings to a UKCS prospect to investigate whether this could support the prospect becoming economically viable. Centrica’s West Pegasus field, a three well tie-back in the southern North Sea, was chosen as a case study. In all, by applying the standardisation themes, the group identified savings of up to 25 per cent through design optimisation; revised field layouts; manifold simplification; pipeline, flexible riser and umbilicals optimisation; efficiencies in valves, trees and controls systems manufacturing; and by combining umbilicals in pipeline trenches. Steve says: “Our work on West Pegasus shows us that the three areas with the most potential to deliver cost and schedule savings are in processes; code, standards and specifications; and alternative methods and technology. There are opportunities in standardising hardware too, but these may be constrained by commercial sensitivities arising from proprietary equipment within individual companies; however, there is the potential for significant savings in the longer term.” >

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More than three billion barrels of oil equivalent (boe) are stranded in around 350 unsanctioned discoveries

Of less than 50 million boe each, these ‘small pools’ are currently economically challenging to produce

Early engagement with the supply chain is important. “ ”

Subsea trenching plough. Image courtesy of Technip

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| W I R E L I N E | SPRING 2017