<p>The invention, which can be applied to both starting mills and window mills for use in sidetracking a cased borehole, makes use of carbide discs as cutting elements and the geometrical disposition of blades on which the discs are mounted to enhance cutting efficiency. The blades are angularly offset with respect to the tool centreline in a variety of configurations. <IMAGE></p>
申请公布号
EP0442675(A2)
申请公布日期
1991.08.21
申请号
EP19910301060
申请日期
1991.02.11
申请人
TRI-STATE OIL TOOL (UK), A DIVISION OF BAKER HUGHES LIMITED