Packer apparatuses

Abstract

A packer apparatus for providing an annular seal in a wellbore is described. The packer apparatus has a body defining a first bore to enable working fluid such as hydraulic fracturing fluid containing proppant to flow through the packer apparatus. A first channel is formed in the body and is arranged to hold hydraulic fluid. A first floating piston is disposed in the first channel, the first floating piston being in fluid communication with the first bore via a passage. A plurality of pistons is arranged to move the activation member relative to the body to deform an elastomeric packer element outwardly relative to the body.

1 . A packer apparatus for providing an annular seal in a well bore, the apparatus comprising:
 a body arranged to be disposed in a well bore, the body defining a first bore to enable working fluid to flow through the packer apparatus;   a first channel formed in the body for holding hydraulic fluid;   a first floating piston disposed in the first channel, the first floating piston being in fluid communication with said first bore such that working fluid flowing through the first bore is arranged to cause the first floating piston to move along the first channel to pressurise hydraulic fluid disposed in the first channel;   an activation member mounted to the body, wherein the activation member is moveable relative to the body to deform an elastomeric packer element outwardly relative to the body to form an annular seal in a well bore in use; and   a plurality of pistons arranged to move the activation member relative to the body, each said piston defining a respective pressure chamber being in fluid communication with said first channel such that pressurisation of the hydraulic fluid moves each of the plurality of pistons relative to the body to cause the activation member to move relative to the body to deform the elastomeric packer element outwardly relative to the body.   
     
     
         2 . An apparatus according to  claim 1 , wherein said first channel is an annular channel disposed concentrically around the first bore and said first floating piston comprises an annular member disposed in the annular channel. 
     
     
         3 . A work string for use in a wellbore, the work string comprising:
 a first packer apparatus according to  claim 1 ;   a second packer apparatus according to  claim 1 ; and   a hydraulic fracturing tool connected between said first and second packer apparatuses, the hydraulic fracturing tool comprising:
 a second bore connectable to the respective first bores of the first and second packer apparatuses to enable working fluid to flow through the work string; and 
 at least one nozzle to enable working fluid to flow out of the work string to cause hydraulic fracturing of a formation in which the work string is disposed. 
   
     
     
         4 . A method of hydraulic fracturing a formation to retrieve hydrocarbons, the method comprising:
 locating a work string according to  claim 3  at a location in a well bore at which a hydraulic fracturing operation is to be conducted; and   pumping working fluid through the work string to:
 i. deform the elastomeric packer elements of each said packer apparatus outwardly relative to the work string to form two annular seals in the well bore and form an isolated section of well bore located between the two respective annular seals; and 
 ii. cause working fluid to be exhausted from the work string through said at least one nozzle into the isolated section of well bore to cause hydraulic fracturing of the formation at the location of the isolated section of well bore. 
   
     
     
         5 . A packer apparatus for providing an annular seal in a well bore, the apparatus comprising:
 a body arranged to be disposed in a well bore, the body defining a third bore for holding hydraulic fluid;   a second floating piston disposed in the third bore such that working fluid pumped into said third bore causes the second floating piston to move along the third bore to pressurise hydraulic fluid disposed in the third bore;   an activation member mounted to the body, wherein the activation member is moveable relative to the body to deform at least one elastomeric packer element outwardly relative to the body to form an annular seal in a well bore in use; and   a plurality of pistons arranged to move the activation member relative to the body, each said piston defining a respective pressure chamber being in fluid communication with said third bore such that pressurisation of the hydraulic fluid moves each of the plurality of pistons relative to the body to cause the activation member to move relative to the body to deform said at least one elastomeric packer element outwardly relative to the body.   
     
     
         6 . A work string for use in a wellbore, the work string comprising:
 a first packer apparatus for providing an annular seal in a well bore, the first packer apparatus comprising:
 a body arranged to be disposed in a well bore, the body defining a first bore to enable working fluid to flow through the packer apparatus; 
 a first channel formed in the body for holding hydraulic fluid; 
 a first floating piston disposed in the first channel, the first floating piston being in fluid communication with said first bore such that working fluid flowing through the first bore is arranged to cause the first floating piston to move along the first channel to pressurize hydraulic fluid disposed in the first channel; 
 an activation member mounted to the body, wherein the activation member is moveable relative to the body to deform an elastomeric packer element outwardly relative to the body to form an annular seal in a well bore in use; and 
 a plurality of pistons arranged to move the activation member relative to the body, each said piston defining a respective pressure chamber being in fluid communication with said first channel such that pressurisation of the hydraulic fluid moves each of the plurality of pistons relative to the body to cause the activation member to move relative to the body to deform the elastomeric packer element outwardly relative to the body; 
   a third packer apparatus for providing an annular seal in a well bore, the third packer apparatus comprising:
 a body arranged to be disposed in a well bore, the body defining a third bore to enable working fluid to flow through the packer apparatus; 
 a second floating piston disposed in the third bore, such that working fluid pumped into said third bore causes the second floating piston to move along the third bore to pressurize hydraulic fluid disposed in the third bore; 
 an activation member mounted to the body, wherein the activation member is moveable relative to the body to deform at least one elastomeric packer element outwardly relative to the body to form an annular seal in a well bore in use; and 
 a plurality of pistons arranged to move the activation member relative to the body, each said piston defining a respective pressure chamber being in fluid communication with said first channel such that pressurisation of the hydraulic fluid moves each of the plurality of pistons relative to the body to cause the activation member to move relative to the body to deform said at least one elastomeric packer element outwardly relative to the body; and 
   a hydraulic fracturing tool connected between said first and third packer apparatuses, the hydraulic fracturing tool comprising:
 a fourth bore connectable to the first bore of the first packer apparatus and the third bore of the third packer apparatus; and 
 at least one nozzle to enable working fluid to flow out of the work string to cause hydraulic fracturing of a formation in which the work string is disposed. 
   
     
     
         7 . A method of hydraulic fracturing a formation to retrieve hydrocarbons, the method comprising:
 locating a work string according to  claim 6  at a location in a well bore at which a hydraulic fracturing operation is to be conducted; and   pumping working fluid through the work string to:
 i. deform the elastomeric packer elements of each said packer apparatus outwardly relative to the work string to form two annular seals in the well bore and form an isolated section of well bore located between the two respective annular seals; and 
 ii. cause working fluid to be exhausted from the work string through said at least one nozzle into the isolated section of well bore to cause hydraulic fracturing of the formation at the location of the isolated section of well bore. 
   
     
     
         8 . A work string for use in a wellbore, the work string comprising:
 a first packer apparatus according to  claim 2 ;   a second packer apparatus according to  claim 2 ; and   a hydraulic fracturing tool connected between said first and second packer apparatuses, the hydraulic fracturing tool comprising:
 a second bore connectable to the respective first bores of the first and second packer apparatuses to enable working fluid to flow through the work string; and 
 at least one nozzle to enable working fluid to flow out of the work string to cause hydraulic fracturing of a formation in which the work string is disposed. 
   
     
     
         9 . A method of hydraulic fracturing a formation to retrieve hydrocarbons, the method comprising:
 locating a work string according to  claim 8  at a location in a well bore at which a hydraulic fracturing operation is to be conducted; and   pumping working fluid through the work string to:
 i. deform the elastomeric packer elements of each said packer apparatus outwardly relative to the work string to form two annular seals in the well bore and form an isolated section of well bore located between the two respective annular seals; and 
 ii. cause working fluid to be exhausted from the work string through said at least one nozzle into the isolated section of well bore to cause hydraulic fracturing of the formation at the location of the isolated section of well bore.