Downhole plug

Abstract

A downhole plug for plugging and method of controlling fluids within a borehole in an oil and/or gas well. The downhole plug has a body having a throughbore for the passage of fluids. The plug also has a mechanical anchoring device that can radially expand an anchoring member on an outer surface of the body to lock the body in a fixed axial position within the borehole and an annular sealing device that can radially expand a sealing member on the outer surface of the body to seal an annulus formed between the outer surface of the body and an inner surface of the borehole. The plug also has a throughbore plugging device that can change configuration between a first open configuration in which the throughbore of the body permits the passage of fluid, and a second closed configuration in which the throughbore resists the passage of fluid.

What is claimed is: 
     
         1 . A downhole plug for plugging a borehole in an oil and/or gas well, the downhole plug comprising:
 a body having a throughbore adapted to permit the passage of fluids through the throughbore;   a mechanical anchoring device adapted to radially expand an anchoring member on an outer surface of the body to lock the body in a fixed axial position within the borehole;   an annular sealing device adapted to radially expand a sealing member on the outer surface of the body to seal an annulus formed between the outer surface of the body and an inner surface of the borehole; and   a throughbore plugging device adapted to change configuration between a first open configuration in which the throughbore of the body permits the passage of fluid, and a second closed configuration in which the throughbore resists the passage of fluid.   
     
     
         2 . A downhole plug according to  claim 1 , wherein the mechanical anchoring device has gripping formations for locking the body in a fixed axial position within the borehole. 
     
     
         3 . A downhole plug according to  claim 2 , wherein the gripping formations comprise teeth or abrasive material. 
     
     
         4 . A downhole plug according to  claim 1 , wherein the mechanical anchoring device comprises one or more wedge devices in the form of slips having tapered surfaces adapted to expand the radial dimensions of the anchoring member due to relative axial movement of the slips. 
     
     
         5 . A downhole plug according to  claim 4 , wherein the slips are moveable axially by an actuator of the mechanical anchoring device, the anchoring device being moveable axially relative to the body. 
     
     
         6 . A downhole plug according to  claim 4 , wherein the slips are moveable axially by a piston of the mechanical anchoring device, the anchoring device being moveable axially relative to the body. 
     
     
         7 . A downhole plug according to  claim 1 , wherein the anchoring member is a grapple device having collet fingers attached to the mechanical anchoring device in a cantilever manner, free ends of the fingers are movable radially outwards from an axis of the body into contact with the inner surface of the borehole. 
     
     
         8 . A downhole plug according to  claim 7 , wherein the other ends of the fingers are connected by a ring. 
     
     
         9 . A downhole plug according to  claim 1 , wherein the throughbore plugging device comprises a plugging member adapted to engage on a seat within the throughbore of the body. 
     
     
         10 . A downhole plug according to  claim 9 , wherein the throughbore plugging device has a sealing arrangement in the form of an annular seal set in an inner surface of the throughbore adjacent to the seat. 
     
     
         11 . A downhole plug according to  claim 1 , wherein the inner surface of the borehole is the inner surface of casing located in the borehole. 
     
     
         12 . A downhole plug for plugging a borehole in an oil and/or gas well, the downhole plug comprising:
 a body having a throughbore adapted to permit the passage of fluids through the throughbore;   a mechanical anchoring device adapted to radially expand an anchoring member on an outer surface of the body to lock the body in a fixed axial position within the borehole;   an annular sealing device adapted to radially expand a sealing member on the outer surface of the body to seal an annulus formed between the outer surface of the body and an inner surface of the borehole;   a throughbore plugging device adapted to change configuration between a first open configuration in which the throughbore of the body permits the passage of fluid, and a second closed configuration in which the throughbore resists the passage of fluid; and   wherein the mechanical anchoring device comprises one or more wedge devices in the form of slips having tapered surfaces adapted to expand the radial dimensions of the anchoring member due to relative axial movement of the slips.   
     
     
         13 . A downhole plug according to  claim 12 , wherein the anchoring device comprises an upper slip, a lower slip and a grapple sleeve. 
     
     
         14 . A downhole plug according to  claim 12 , wherein the slips have inwardly facing opposed faces. 
     
     
         15 . A downhole plug according to  claim 14 , wherein the inwardly facing opposed faces have tapered edges. 
     
     
         16 . A method of controlling fluids within a borehole of an oil and/or gas well, the method comprising providing a well control device having a body with a throughbore for fluid passage through the body, a mechanical anchoring device for anchoring the body in a fixed axial position within the borehole, an annular sealing device for sealing the annulus between the body and the borehole and a bore plugging device for closing the fluid pathway through the body, wherein the method comprises the steps of:
 running the body into the borehole;   activating the mechanical anchoring device in order to fix the body in the borehole and resist axial movement of the body within the borehole;   activating the annular sealing device to seal the annulus between the body and the borehole, thereby substantially resisting passage of fluid within the annulus past the annular sealing device; and   plugging the throughbore in the body to resist fluid passage through the throughbore.   
     
     
         17 . A method of controlling fluids according to  claim 16 , wherein the mechanical anchoring device comprises an anchoring member on an outer surface of the body and the borehole has an inner surface, the step of activating the annular sealing device includes sealing the annulus between the outer surface of the body and the inner surface of the borehole. 
     
     
         18 . A method of controlling fluids according to  claim 16 , wherein the annular sealing device is moved from a radially unexpanded configuration to a radially expanded sealing configuration by setting weight down on the well control device after the mechanical anchoring device has been activated and the body is locked in a fixed axial position within the borehole. 
     
     
         19 . A method of controlling fluids according to  claim 16 , wherein the step of activating the mechanical anchoring device includes expanding the mechanical anchoring device.