Page 46: of Offshore Engineer Magazine (Sep/Oct 2016)

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Left: The Britannia BLP.

Inset below: Britannia and the long term compression module. Photos from ConocoPhillips

BP, at Devex. It also become the ? rst time

Old fields,

BP retro? tted gas lift technology using a light well intervention (LWI) vessel.

Monan was discovered in the central

PRODUCTION

North Sea in 1990 and started produc- tion from two wells, 130 and 131, in new tricks 1998. Arti? cial lift wasn’t originally considered for the ? eld, brought online during CRINE (cost reduction initia- tive for the new era), and initially it had good stable producers. But, production rates declined rapidly. By 2001, well 130 was lost altogether and well 131 struggled to maintain a stable ? ow.

By 2014, after coiled tubing interven- tions in both wells in 2001 and again in 2008, including retro? tting gas lift on well 130, both wells were of? ine, with downhole safety valves stuck in closed position. “It was going to take signi? cant investment and a number of complex activities to reinstate the wells so it didn’t look very favorable as an op- portunity,” McKevitt says.

However, a look at data from well 130, to look at well 131, suggested there was a signi? cant prize making it worth a try. So, the ? rm took another look on the basis of performing a reinstatement project, including retro? tting gas lift. “The key issues were: we didn’t un- derstand if we could reopen the down- hole safety valve; we had a complex well trajectory to begin with; well access issues – well 130 had history; we were unsure what we were going to see – it was more than 14 years since we were last in the well so there was uncertain- ty,” McKevitt says. “We needed to assess if well 131 had the necessary well integ- is because they need a new export route or rity requirements for a change of service because past interventions haven’t quite to gas lift. We also needed to understand done the trick, was a common theme at if the well could be con? gured for gas this year’s Devex conference in Aberdeen. lift by punching the tubing and setting

BP outlined how it’s brought new life gas lift straddles as we didn’t have the to the Monan ? eld and ConocoPhillips luxury of side pocket mandrels. We also

Time and greater understanding described the epic journey the Britannia knew a rig wouldn’t work based on cost. makes most people and complex has been on. The key to doing this project was doing companies look at projects and it off an LWI vessel.”

Ugly ducking

Reinstating the wells would require: assets di