Magnetic retrieval apparatus and method for retaining magnets on downhole magnetic retrieval apparatus

摘要

Magnetic retrieval tools for use in a wellbore or other tubular member to remove metallic debris. A magnetic retrieval tool includes a tool body having a central shaft with a plurality of ribs that project radially outwardly therefrom. The ribs present lateral sides that have recesses formed therein. Magnet bars are retained within the recesses by wedge members and retaining rings. The magnet bars include a hollow protective housing that encloses a plurality of magnets. Retaining plugs are used to secure the magnets within the housing.