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hrysaor is a new operator on the UK Continental soon as it falls below 48°C the wax falls out,” says Emily Ead-

Shelf. Only about 18 months old, it’s got growth ington, Wells & Subsea Projects Manager, at Chrysaor. “When ambitions, after ? rst acquiring a package of assets the line was installed in 1992, there were only Lomond ? uids

Cfrom Shell in 2017 in a $3.8 billion deal. to transport, so wax was not an issue, thus no insulation.” In

But, acquiring existing producing assets can come with is- 1997, Erskine condensate was added, and in order to mitigate sues, including that they’re older, complex, interconnected potential wax-build up, a strategy to pig the pipeline every two and have been through multiple owners and therefore might weeks was developed. “But, it was last pigged in 2009. When not come with complete records – including exactly where we took it over, you couldn’t put a PIG in because the PIG and what diameter pipelines are. could get stuck.”

The Lomond platform (initially operated by Amoco, BP, BG Chrysaor needed to clear the pipeline before it became

Group and then Shell) sits 145m east of Aberdeen in 83.8m blocked again. But, clearing it might not be that easy. “There water depth and started producing in 1993. Gas condensate was a debate if we should clear it or bypass it,” says Eading- from the Erskine facility, operated by Chevron, is exported to ton. “We decided to just try and carefully maintain ? ow rather the Lomond platform and then 57.8km on to the Everest plat- than unlock it and, in the meantime, put in a bypass pipeline as form for onward export via the CATS system into the Forties the chances of it blocking while we were trying to unblock it

Pipeline System to shore. were 50%.” So, late 2017, while the pipeline was still ? owing,

When Chrysaor took on Lomond as part of its acquisition Chrysaor started engineering work with Subsea 7, which had of (ex-BG Group) assets from Shell in 2017, it knew there previously performed engineering on a solution for a bypass was a history of blockages in the Lomond to Everest conden- pipeline under a previous owner operator. sate line, due to wax dropping out of the condensate ? ow as it Then, in January 2018, the very day Chrysaor secured cooled. While condensate from Erskine is transported through partner (Chevron and Serica Energy) agreement to invest in an insulated pipeline from Erskine to Lomond - stopping it the bypass pipeline, the Lomond-Everest pipeline became falling to temperatures where wax forms - the Lomond to blocked. The project’s urgency was now escalated. What

Everest pipeline isn’t insulated. would normally be an 18-month project needed to be done as “As it leaves Lomond, where the line is not insulated, as quickly as possible.

Navica Pulling Head welding onto Stalk #1

Images courtesy Chrysaor and Subsea 7

May 2019 50


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