公开(公告)号：WO1998016720A1

公开(公告)日：1998-04-23

申请号：PCT/US1997018304

申请日：1997-10-09

Applicant: DAILEY PETROLEUM SERVICES CORP.

Inventor： DAILEY PETROLEUM SERVICES CORP. ,  BEASLEY, Thomas, R.

IPC: E21B44/00

CPC classification number: E21B44/005 ,  E21B4/18 ,  E21B23/04 ,  E21B47/091

Abstract: The present invention is an improved apparatus for controlling the weight on the drill bit during operation. In this invention, an inner mandrel (1) has a telescoping movement in response to added drill string length at the surface. As the inner mandrel telescopes closed, it approaches a restrictor (5) which is fixedly disposed in the lower housing (4) of the drill string assembly. When the inner mandrel mates with the restrictor, a stand-pipe pressure increase occurs noticeable to the operator. The operator then stops the drill string and allows the motor to drill ahead. As the motor drills ahead, the inner mandrel telescopes open and the operation is then repeated.

Abstract translation: 本发明是用于在操作期间控制钻头的重量的改进的装置。 在本发明中，内心轴（1）响应于在表面处的钻柱长度增加而具有伸缩运动。 当内心轴望远镜闭合时，它接近固定地设置在钻柱组件的下壳体（4）中的限流器（5）。 当内心轴与限流器配合时，操作人员可以看到立管压力增加。 然后操作员停止钻柱，并允许电机向前钻。 当电机向前钻时，内心轴望远镜打开，然后重复操作。