BOTTOM HOLE ASSEMBLY FOR CASING WINDOW MILLING

摘要

A bottom hole assembly (12) for use in cutting a window in a wellbore casing wall. An exemplary bottom hole assembly is described which includes a shaft that carries a window mill (24). A pair of bearing mills (26,28) is carried by the shaft (17) above the window mill. Placement of the bearing mills permits the bottom hole assembly to cut a window having a greater length and quality (gage width and reduced burrs/slivers) than windows cut by other bottom hole assembly designs.