| 摘要 |
A tube-guide is fixed to the sea bed at a well head by means of a ball joint so that its vertical orientation can be adjusted. A centring gauge is fixed to the tube-guide and is surrounded by a protective casing. Connected to the casing is a framework that is fitted with jack screws for centring the tube-guide in relation to the wall of a cylindrical opening at the top of the protective casing. The jack screws are fixed to a support plate that rests on the top of the protective casing. Another set of jack screws fixed to the tube-guide adjust the height of the tube-guide by jacking off of the support plate. The top of the tube-guide is of sufficient height from the well that the drilling earthworks are deposited outside the casing. The device is used for protection of drilling heads when drilling under sea wells. It ensures absolute verticality of the tube-guide sealed in the sea bed and hence the well. |
