| 摘要 |
The invention provides a method of drilling and a drilling apparatus and drilling apparatus set. The apparatus includes a drill rig (12), a flexible string (18) of drill rods connected to the rig, a steerable downhole motor (22) connected to the string, a drill bit (24) connected to the motor (20) and monitoring means for detecting changes in the rate of movement of the drill bit. The method involves steering the motor to cause the bit to drill and at least partly curved borehole, the drilling being monitored to detect changes in the drilling which are indicative of discontinuities in sub-surface formations. |
