Page 42: of Offshore Engineer Magazine (Aug/Sep 2016)

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Raising

SUBSEA resin’s pro? le formation wall. This interface

Endeavor Management’s can follow variations in the

Keith Caul? eld and Mike Cowan mating surface. There can be a chemical bond component to examine the results of a recent formation and casing, but the

JIP that showed resin may be a overall sealing bond is mainly a mechanical bond de? ned by potential alternative to cement friction and a solid-to-solid in P&A operations.

interface.

A broad analogy describ- ing the way cements seal is “the clamp.” A clamp applies ndeavor Management recently mechanical load (compression) completed a joint industry to the items being secured.

E project (JIP) covering covering Mechanical seals in a clamped several subjects related to the decom- joint need the force provided by missioning industry. One that was of the clamp to create the seal. As intense interest to JIP member compa- long as the clamp remains, the nies was the use of resins for well plug- system is stable. Move, jiggle, or ging and abandonment (P&A). relax the clamp and the proper-

Endeavor Management has re- ties of the entire system are searched the potential for resin as an changed for the worse.

alternative to cement. We set out some For resins, the sealing mecha-

At the interface between cement and of the conclusions here. nism is completely different. At the for- formation, the solids-laden cement does For years, resins have been viewed as mation interface, resins – being liquid not penetrate very far into the pores, a dramatic upgrade to cements for many during placement – penetrate far deeper leaving a seal that exists virtually at the uses in well construction, remediation, into the formation than cements. With and P&A. However, three factors have contributed to keep resins from being more widely used: the “durability gap,” dealing with uncertainty of the long- term durability of resins, the “knowledge gap,” created by the lack of resin-trained indus- try personnel, and the percep- tion that resins are much more expensive than cement.

Sealing comparison

Any P&A barrier must create a “sealing boundary” between the different regions of a well: • Sealant/formation •

Sealant/outer casing surface •

Sealant/inner casing surface

Cements are placed as a liquid full of solids-in-suspen- sion. As cements hydrate, they cure into a rock-like solid. Any seal created is predominantly mechanical.

August 2016 | OE oedigital.com 44 044_OE0816_Subsea4_JIP.indd 44 7/24/16 3:18 PM