A method of translating a member through a bore comprises moving fluid through a tubular member such as a drill string (2A), and generating impulses on the member by varying the passage of fluid through the member using a valve (60) which opens at a first rate and closes at a different second rate to urge the member to advance in a selected direction. The valve may close quickly and open slowly, or may close slowly and open quickly.
申请公布号
CA2780236(A1)
申请公布日期
2011.05.19
申请号
CA20102780236
申请日期
2010.11.10
申请人
NATIONAL OILWELL VARCO, L.P.
发明人
EDDISON, ALAN MARTYN;COULL, DAVID ANDERSON;STUART, DEREK JAMES