| 摘要 |
<p>Drilling towards a target from an initial vertical shaft along a curved axis is carried out by means of equipment including at the bottom of a train of boring bars, a subterranean motor, and a cutter head. A diversion of the line of boring in a given direction is brought about by means of an elbow joint placed between the subterranean motor and th boring bars. The guiding of the end of the train of boring bars is ensured, independently of the diversion >=1 guiding device. This has a form which brings it into contact with a limited zone of the periphery of the borehole, so as to allow a certain latitude in the direction of the diversion; the device being suitably aligned relatively to the elbow joint. Makes it possible to hold the elbow joint in the position necessary for drilling in the new direction desired. Both the inclination and the azimuth can be corrected easily.</p> |
