Recovering debris that could cause complications

Nexen was concerned that downhole debris would cause complications when running the screens and setting the liner in a well in the Golden Eagle field. The debris was the result of two separate runs. While drilling the 8 1/2-in reservoir section, penetration was lost, and no progress was being made. Pulling out of hole revealed severe damage to the bit due to a lost bit cone, cutter, and matrix. Running back in with a second bit allowed Nexen to reach TD; however, during the run, a piece of debris from a conventional MWD tool was lost in the hole.

Facilitating the successful installation of screens and a liner hanger

The three magnets used in the BHA recovered 44 kg of shavings and flakes from the wellbore. During the operation, the wiper trip BHA was run to the top of the casing shoe at 3,937 m [12,917 ft]; the string was then washed in to TD, and no issues or drag were observed. On bottom, circulation and rotation were staged up, and the open hole was then displaced with invert-emulsion completion fluid. The BHA was pulled back into the casing shoe and the mud system circulated to production screen test specifications.

The BHA was laid out at surface, and the following debris volumes were recovered:

This allowed Nexen to run the screens to depth and to successfully run and set the liner hanger. The customer is now including the MAGNOGARD magnet on subsequent wiper trips.