Cost Reduction in Well Abandonment Operations, Utilising One Trip Solution for Casing Recovery and Advance Cutting Inserts Technology for Wellhead and Conductor Recoveries

Abstract The service company has been working with several operators to provide casing cutting and recovery operations. Currently, the casing cutting and pulling operation requires multiple trips to set a bridge plug, cut casing, and then recover to surface, even more so, when multiple cuts have to be made. The challenge was to design a new bottom hole assembly which allows on-demand activation of the tools to perform multiple operations in the same trip. Likewise, it was also an objective to develop an advanced cutting structure to enable reduced cutting times for recovery of dual or triple casing sections such as 9-5/8″ × 20″ × 30″ or casing conductors such as 22″ × 36″. To address the operational challenges, a new Efficient Cut and Pull (ECP) system was developed to perform the multiple operations in an efficient way to save trips and reduce rig time. A Flow Thru Pipe Cutter (FTPC) was designed with a through-bore and activation system to consolidate multiple operations such as setting a Bridge plug or dressing a cement plug into the cut-and-pull trip. A hydraulically activated Extended Reach Spear (ERS) is placed directly above the FTPC to assist with the cutting and pulling operations. Both tools were independently qualified using lab testing. Similarly, the advanced cutting structure was rigorously tested in the lab and field with newly designed inserts supported by modelling, simulation, and physical testing. The ECP system has been successfully tested in the field and performed multiple runs on challenging wells in the North Sea and Middle East. It has been widely implemented on workover rigless units and resulted in several days of time savings. Cutting times on dual and triple casing recovery have been improved substantially with a record recovery of conductors in subsea wells. The Efficient cut and pull system has been designed with additional features such as on-demand tension set packer for packoff and annular circulation and other operations such as cementing through the string to complete cementing in the same trip after setting of a bridge plug.