Claims
- 1. A device for overcoming friction and applying impact energy to an object stuck within an oil or gas well, in order to loosen and disengage said stuck object through the application of pressure changes to a liquid flowing within the bore of a coilable tubing or a drill string, and wherein a valve body is adapted to seal against a valve seat and shut off the liquid flow whenever the flow rate exceeds a predetermined value, thus giving rise to a build-up of pressure in the liquid flow, until a pressure fall is caused upstream of the valve body, said valve body further is adapted to maintain the closed position thereof, shutting off the liquid flow, when the flow rate exceeds a predetermined value, and that the valve body is assigned a slide adapted to open for a liquid stream past the valve body, in order to reduce the pressure in the liquid upstream of the valve body, whenever the pressure in the liquid upstream of the valve body exceeds a predetermined value, and wherein a part of the valve body is assigned a damping device, restricting the speed of the valve body during part of the movements thereof from opened to closed and from closed to opened position, and wherein the damping device comprises at least one piston in the form of a collar providing resistance against being moved within an annular space filled with liquid, said collar being provided with a flow resistor in the form of a channel.
- 2. A device as claimed in claim 1, wherein the collar is provided with a check valve which for one flow direction allows liquid flow parallel to the liquid flow in the channel.
Priority Claims (1)
Number |
Date |
Country |
Kind |
962429 |
Jun 1996 |
NO |
|
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to PCT Application No. PCT/NO97/00147 filed Jun. 6, 1997 which claims priority from Norwegian Patent Application No. 962429 filed Jun. 6, 1996.
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
102e Date |
371c Date |
PCT/NO97/00147 |
|
WO |
00 |
11/25/1998 |
11/25/1998 |
Publishing Document |
Publishing Date |
Country |
Kind |
WO97/46791 |
12/11/1997 |
WO |
A |
US Referenced Citations (9)
Foreign Referenced Citations (2)
Number |
Date |
Country |
0 333 484 |
Sep 1989 |
EP |
515630 |
Jan 1985 |
NO |