Sidetrack through tubing with ability to resume production from original wellbore
To sidetrack through tubing from a 21.7° deviated well in the North Sea, an operator required a window in 5-in, 15-lbm/ft, 13% chromium liner, through which a directional assembly capable of a 45°/100-ft build rate could be deployed. The whipstock had to be left in place to facilitate future reentry of the lateral, and production from the original bore had to be maintained once the lateral was drilled.
Run TrackMaster TT whipstock system designed for the purpose
TrackMaster TT thru-tubing whipstock system is designed to pass through the tubing ID; once below the tubing string, it can be hydraulically anchored inside the liner to enable window milling operations. Its unique geometry compensates for the relative size difference between the whipstock and casing diameters. Fluids can flow past the whipstock, which is left downhole, allowing production to be maintained from the original borehole as well as the lateral. The back of the whipstock was fluted to provide additional flow area. A 4.2-in-OD FasTrack one-trip mill was used to create the window at 3,024 m; PDC inserts were used over 30% of the cutting structure.