Well Bore Casing Mill With Expandable Cutter Bases

摘要

A casing mill for downhole casing milling has multiple elongated cutter bases hingedly connected to a main body by a plurality of positioning arms. An operating mechanism within the main body of the casing mill, actuated by fluid flow, moves the cutter bases to an extended position. Multiple cutters fixed to the cutter bases are then positioned to engage a casing end surface. Preferably, the cutters are arranged in vertically spaced apart rows, such that when one row is worn out in the milling process a visual indication is seen at the surface, as the casing mill drops to the next row of cutters.

主权项

1. A casing mill, comprising:
an elongated main body having a bore and a means for attachment to a drillstring; a plurality of elongated cutter bases hingedly connected to said main body and movable between a first position substantially retracted to said main body, and a second position extended outwardly from said main body; one or more cutters mounted on each of said cutter bases, said cutters positioned so as to be in cutting relationship with a casing string when said cutter bases are in said second position; and a means for moving said cutter bases between said first and second positions.