Conductor cement top up system assures vital conductor integrity
Vital conductor integrity, ensured at the point of installation with a novel solution that has since become a product called off by numerous operators.
Earlier wells in the vicinity of Well 7/4-2 Nemo field, offshore Norway, had required remedial cementing. A requirement to minimise lateral deflection of the riser–conductor system to limit the load necessitated a cement top-up for Well 7/4-2 to ensure that the 30-in. conductor was fully cemented to the seabed. The client approached Claxton for technical advice and guidance on the design, specification and manufacture of a cement top-up system.
Before and after using the Claxton cement top-up system.
A secondary cementing system was designed for installation at the same time as the conductor to enable cement filling of possible voids in the annulus between the conductor and 36-in. well hole.
Owing to the well’s depth, the cement top-up system was fixed to the 30-in. conductor before installation and run through the 36-in. hole section to a depth of approximately 30 m below the mudline. The system was connected to the cementing unit topside by means of a 1½-in. grouting hose deployed on a powered umbilical reel. A remotely operated vehicle quick connector was used to connect the hose subsea.
The Claxton cement top-up system enabled the client to perform a secondary cement job offline and thereby save a significant amount of rig time and ensure a good cement job.
Claxton was able to deliver a quick, workable solution following months of cementing difficulties.