PowerMag® casing magnets deliver unmatched debris recovery

Overview

A deepwater well at a depth of more than 3,000 ft required a cased hole sidetrack at approximately 23,000 ft in 14-in. heavyweight casing. The first sidetrack was run using a competitor’s whipstock and milling assembly and PowerMag® casing magnets. However, this operation was ultimately considered unsuccessful after subsequent drilling runs were unable to pass through the window. This occurred despite a dedicated cleaning run to condition the window exit area in the casing.

After the failed window milling operation, the operator engaged a different service provider to mill a new window approximately 200 ft above the previously drilled window. Two separate window milling runs were completed using PowerMag casing magnets for debris recovery, which allowed the operator to begin the sidetrack and continue drilling. 

Challenge

An excessive amount of large swarf and ferrous debris were generated by the milling window operations in the heavyweight 14-in. casing.

Solution

To maximize downhole debris recovery, Halliburton recommended 7 5/8-in. OD PowerMag casing magnets. These casing magnets can be run in any casing size from 9 5/8 to 14 in. Designed to collect ferrous and non-ferrous material that has become magnetically charged during pipe rotation and other movements, a PowerMag casing magnet is equipped with 20 collection areas armed with neodymium bar magnets and has a recovery capacity that exceeds 250 lb/run. The integral body water coursing provides a large external total flow area, even when the tool is at capacity with debris. The total recessed collection surface area is 2,800 square inches to maximize both flow and surface area, and the tool will not pack off the annulus even when full. PowerMag® casing magnets are built from an integral drill collar bar stock to provide high-tensile, high-torsion strength and are ideal for applications, such as window milling or displacement where large amounts of debris are expected or being generated.

Additionally, the PowerMag casing magnets can be quickly cleaned with a custom cleaning tool that allows them to be quickly rerun, if necessary. The capability to clean the magnets quickly is critical during window milling operations. For instance, in this well, a window cleaning/polishing run might become necessary, or milling equipment can be under gauge once measured on the surface, which requires an additional run and further increases operational costs.

Result

An average of 94% of the debris was recovered downhole and more than 7,500 lb of metal was removed during four window milling/cleaning runs. This highlights the efficiency of the PowerMag casing magnet design for ferrous debris recovery. Maximizing debris recovery downhole helps minimize debris at the surface (using ditch magnets) and can prevent metal from remaining in various points of the mud system as operations continue beyond window milling. As demonstrated, PowerMag casing magnets provide unmatched performance for downhole debris recovery when large amounts of ferrous debris are present or being generated.