| 摘要 |
<p>An apparatus 1 for changing direction during driving of a tubular, such as an offshore conductor casing 2, into a formation to establish a wellhead. The apparatus includes a drive shoe 4 connectable to a tubular and having a plurality of independently deployable elements 7 offering deflector surfaces to the formation. There may be four interlocked shoe elements, each slidably mounted along one side of a square support block which is fixed in position within the lower end of a conical, wedge like, or inclined drive shoe 4. The shoe elements may be selectively displacable axially with respect to the tubular. Each shoe element may be interconnected by keying surfaces (12, figure 2). There may be hydraulic actuator providing control means to drive movement of the shoe elements.</p> |
