Pressure actuated jarring device for use in a wellbore

Abstract

A pressure actuated jarring apparatus includes a tubular housing, a piston, a spring element, and a seat. The tubular housing has a passage therethrough extending from an upper end to a lower end. The piston is disposed within the central bore and is movable axially between an inactivated state and an activated state. The spring element is configured to store energy to drive the piston from the activated state. The seat is coupled to the piston such that when a plug is seated in an orifice of the seat fluid is prevented from flowing through the orifice. The jarring device is fired by increasing pressure in the passage until the plug is forced through the seat, thereby releasing the energy in the spring element and driving the piston from the activated state so that it impacts an abutment and generates a jarring force.

What is claimed is: 
     
         1 . A pressure actuated jarring apparatus for use in a wellbore, comprising:
 a tubular housing having a passage therethrough extending from an upper end to a lower end;   a piston disposed within the passage of the tubular housing and movable axially within the passage between an inactivated state and an activated state;   a spring element disposed within the tubular housing to store energy to drive the piston from the activated state; and   a seat coupled to the piston and having an orifice, such that when a plug is seated in the seat the orifice is blocked and fluid is prevented from flowing through the orifice,   wherein, when the orifice is blocked and the piston is in the activated state, the pressure actuated jarring apparatus is fired by increasing fluid pressure in the passage until the plug is forced through the seat, thereby opening the orifice, releasing the energy in the spring element and driving the piston from the activated state so that it impacts an abutment and generates a jarring force.   
     
     
         2 . The pressure actuated jarring apparatus of  claim 1 , wherein the tubular housing includes an upper tubular housing and a lower tubular housing. 
     
     
         3 . The pressure actuated jarring apparatus of  claim 1 , wherein the piston includes an upper piston and a lower piston disposed within the tubular housing and movable axially within the passage between the inactivated state and the activated state. 
     
     
         4 . The pressure actuated jarring apparatus of  claim 3 , wherein the upper piston includes one or more ports through a shaft of the upper piston configured to allow fluid traveling through the pressure actuated jarring apparatus to pass through the one or more ports and into a cavity formed between the shaft of the upper piston, the tubular housing, and a top face of the lower piston. 
     
     
         5 . The pressure actuated jarring apparatus of  claim 1 , wherein a sealed annulus is formed between the piston and the tubular housing and the spring element is disposed within the sealed annulus and wherein the sealed annulus is at least partially filled with a compressible fluid. 
     
     
         6 . The pressure actuated jarring apparatus of  claim 1 , wherein the piston defines a cavity configured to receive and retain the plug after the plug passes through the orifice of the seat. 
     
     
         7 . The pressure actuated jarring apparatus of  claim 1 , wherein the orifice of the seat is expandable from a first configuration to a second configuration, and wherein the plug is unable to pass through the orifice when in the first configuration and is able to pass through the orifice when in the second configuration. 
     
     
         8 . The pressure actuated jarring apparatus of  claim 7 , wherein the seat is axially movable relative to the piston from a first position to a second position, and wherein the orifice is restricted from expanding when the seat is in the first position and is able to expand when the seat is in the second position. 
     
     
         9 . The pressure actuated jarring apparatus of  claim 8 , further comprising a biasing member disposed between the seat and the piston, the biasing member configured to bias the seat toward the first position. 
     
     
         10 . The pressure actuated jarring apparatus of  claim 1 , further comprising a second seat. 
     
     
         11 . A pressure actuated jarring apparatus for use in a wellbore, comprising:
 a tubular housing having a passage therethrough extending from an upper end to a lower end, wherein the upper end is configured to couple to a workstring or coiled tubing sub and the lower end is configured to couple to a fishing tool;   an upper piston disposed within the passage of the tubular housing and movable axially within the passage between an inactivated state and an activated state, the upper piston having one or more ports through a sidewall of the upper piston;   a lower piston coupled to the upper piston, the lower piston having a top face and an elongation, wherein an annular cavity is formed between the elongation and the tubular housing, the annular cavity at least partially filled with a compressible fluid;   a compressible element disposed within the annular cavity to store energy to drive the upper piston and the lower piston from the activated state; and   a seat coupled to the upper piston or the lower piston and having an orifice, such that when a plug is seated in the seat, the orifice is blocked and fluid is prevented from flowing through the orifice,   wherein, when the orifice is blocked and the first and lower pistons are in the activated state, the pressure actuated jarring apparatus is fired by increasing pressure in the passage until the plug is forced through the orifice, thereby opening the central bore, releasing the energy in the compressible element and driving the first and lower pistons from the activated state so that the upper piston impacts an abutment and generates a jarring force.   
     
     
         12 . The pressure actuated jarring apparatus of  claim 1 , wherein the tubular housing includes an upper tubular housing and a lower tubular housing. 
     
     
         13 . The pressure actuated jarring apparatus of  claim 11 , wherein the lower piston defines a cavity configured to receive and retain the plug after the plug passes through the orifice of the seat. 
     
     
         14 . The pressure actuated jarring apparatus of  claim 11 , wherein the orifice of the seat is expandable from a first configuration to a second configuration, and wherein the plug is unable to pass through the orifice when in the first configuration and is able to pass through the orifice when in the second configuration. 
     
     
         15 . The pressure actuated jarring apparatus of  claim 14 , wherein the seat is axially movable relative to the first and lower pistons from a first position to a second position, and wherein the orifice is restricted from expanding when in the first position and is able to expend when in the second position. 
     
     
         16 . The pressure actuated jarring apparatus of  claim 15 , further comprising a biasing member disposed between the seat and the lower piston, the biasing member configured to bias the seat toward the first position. 
     
     
         17 . A method of generating a jarring force to free a stuck object in a wellbore, comprising:
 deploying a first plug through a coiled tubing or workstring until the first plug engages a seat of a jarring apparatus and blocks flow through an orifice of the seat;   pumping a fluid through the coiled tubing or workstring at a pressure sufficient to axially move a piston of the jarring apparatus from an inactivated state to an activated state against a force imparted on the piston by a spring element; and   increasing the pressure of the fluid to force the first plug through the orifice of the seat, thereby releasing the pressure on the piston and allowing the piston to be moved by the spring element to the inactivated state.   
     
     
         18 . The method of  claim 17 , further comprising:
 deploying a second plug through the coiled tubing or workstring until the second plug engages the seat of the jarring apparatus and blocks flow through the orifice of the seat, wherein the second plug has a larger diameter than the first plug;   pumping a fluid through the coiled tubing or workstring at a pressure sufficient to axially move the piston of the jarring apparatus from the inactivated state to the activated state against a force imparted on the piston by the spring element; and   increasing the pressure of the fluid to force the second plug through the orifice of the seat, thereby releasing the pressure on the piston and allowing the piston to be moved by the spring element to the inactivated state.