| 摘要 |
<p>A shoe (10) for guiding a string within a well-bore is described. The shoe comprises an annular body (12) of relatively hard material and a nose portion (16) of relatively soft material which are interlocked so that when the nose portion is drilled through, any remaining parts are held against the annular body. Interlocking is achieved by a dovetail thread (30). Embodiments are described for the shoe as a reamer shoe and as a drill bit to run in casing.</p> |
