Claxton completes rigless removal of a stuck BHA during slot recovery

Posted on 09 July 2014

Claxton deployed its slot recovery methodology and tooling, as well as specialist cutting equipment, to remove a stuck BHA during a slot recovery operation for Maersk Oil.

Claxton deployed its slot recovery methodology and tooling, as well as specialist cutting equipment, to remove a stuck BHA during a slot recovery operation for Maersk Oil.

Claxton Engineering Services, an Acteon company, has completed the first rigless removal of a stuck bottomhole assembly (BHA). The work was completed during a slot recovery operation at Maersk Oil’s Tyra East field in the Danish sector of the North Sea. The well was drilled in the 1980s and, during construction, the BHA had become stuck in the conductor pipe and prevented well completion. Claxton used its slot recovery methodology and tooling, specialist cutting equipment and a dive support vessel to solve the issue.

The program began with the deployment of a specialist casing-cutting system to remove a section of the conductor, which left the stuck BHA intact but exposed. This called for modification of the cutting equipment and the subsea application of a system that is normally used on the surface.

Once the conductor had been cut and removed, Claxton engineers prepared a specialized lifting device using an air hoist on deck deployed through an A-frame, while divers clamped the lifting gear to the BHA. The BHA was too heavy to recover in one piece and had to be cut subsea. This involved using two sizes of diamond wire-cutting machine: the smaller to sever only the exposed BHA, and the larger to cut simultaneously through the remaining conductor stump and the BHA. The cut needed to give a smooth and flush surface on the end of the conductor. Once the cutting machine had sliced through the conductor and the BHA, the top section was recovered.

During planning, the orientation of the remaining BHA relative to the conductor stump was uncertain. Claxton created a whipstock with a slot beneath the landing plate that would enable it to capture the exposed part of the BHA securely in any orientation. The top half of the whipstock would rotate on this base and enable the new well to be kicked off in any direction.

The initial project schedule was 20 days. However, the team completed the operation in less than 16 days, including more than three days waiting on weather.

Alex Lucas, Senior Drilling Engineer with Maersk Oil, said, “This was a very challenging piece of work requiring integrated planning across many departments and companies, not to mention the extensive amount of design, manufacturing and testing of equipment that Claxton designed especially for the job in double-quick time.”

Claxton completed the world’s first rigless platform well abandonment more than a decade ago and has deployed its cutting and recovery tooling on more than 270 successful conductor cutting, recovery and abandonment operations.

 

Leave a Reply

*

FEATURED MICROSITES


Recent Drilling News

  • 29 September 2014

    Rosneft discovers oil in Kara Sea

    Rosneft successfully completed the drilling of the Universitetskaya-1 well in the Arctic – the northernmost well in the world, according to the company, and discovered oil at the East-Prinovozemelskiy-1 license area...

  • 26 September 2014

    Statoil and PL713 partners discover gas in Pingvin prospect in Barents Sea

    Statoil has together with PL713 partners made a gas discovery in the Pingvin prospect in the Barents Sea. The discovery is a play opener in an unexplored frontier…

  • 26 September 2014

    Maersk Drilling names fourth ultra-deepwater drillship, delivery expected in Q4

    Maersk Drilling’s fourth ultra-deepwater drillship was named Thursday morning in a ceremony at the Samsung Heavy Industries (SHI) shipyard in Geoje-Si...

  • 25 September 2014

    Eni awarded 3 new exploration licenses in Egypt

    Eni was the successful bidder of three new exploration licenses in Egypt as a result of the competitive 2013 EGPC and EGAS bid rounds. The new licenses will be formally awarded after the ratification...

  • 25 September 2014

    Petrobras finds gas in Sergipe-Alagoas Basin

    While drilling extension well 3-BRSA-1022-SES (3-SES-181), Petrobras discovered gas. Poço Verde 1 well, 58 km off the coast of Aracaju, is in the Poço Verde Discovery Evaluation Plan area...

  • Read more news