Baker Hughes has announced the commercial release of the Harpoon cut and pull spear, designed for casing removal during plug and abandonment (P&A) and slot recovery operations.
The Harpoon spear can be set and reset several times and enables multiple cut and pull attempts in a single trip, increasing the likelihood of retrieving the casing in one run. This capability is beneficial in situations in which cement stringers, scale build-up and other downhole factors can make pulling the casing at the initial cut point extremely challenging. The spear reduces NPT associated with additional trips, and increases the overall efficiency, safety, and economics of casing removal.
The Harpoon cut and pull spear is run in with a cutting assembly and does not require a stop ring, allowing the spear to engage the casing directly above the cut, ensuring maximum force is distributed at the cut point. FLEX-LOCK slips distribute loads evenly across the entire casing diameter to prevent casing deformation, and the tool applies tension during cutting for improved cutting performance. A built-in filter helps control debris for increased reliability.
The spear’s design also supports loads in both directions so it can accommodate the use of fishing jars. For added safety, the spear features a pack-off device to control circulation paths and provide well control in the event that a pressurized zone is exposed during the cutting operation.
Baker Hughes recently deployed the Harpoon spear to efficiently remove a string of casing for an operator in the Heidrun field in the Norwegian Sea. The operator needed to remove the top section of the casing to make way for a planned openhole sidetracking operation in a deviated well. The team set the tool at depth and made a clean casing cut, but difficulties were encountered when trying to free the casing from the initial cut point. The tool was easily unset, repositioned higher uphole, and reset for another pull attempt. This time, the casing broke free with applied overpull, and the 345.6 m casing string was removed in a single-trip operation that took only 16.5 hours. The operator saved 19.5 hours of rig time and an estimated US$650,000 by completing the operation in one run.