| 摘要 |
<p>In a method of assessing drilling conditions during a drilling operation measurements of torque applied (TOR), weight on bit (WOB), rate of penetration (ROP), and rotation speed (ROT) are gathered. Computed therefrom is a history (60, 61) of points (x, y) where y = (TOR/WOB) and y = (ROP/ROT) : y being a derived constant indicative of down hole geometry. Trends in this history are monitored to assess drilling conditions. For example in soft plastic rock migration 62 towards the origin and in hard plastic rock migration 63 towards the abcissa, is indicative of drill bit wear.</p> |
