Plugging packer shunt tubes using magnetically responsive particles

Abstract

A borehole packer includes a shunt tube and a fluid chamber coupled to the shunt tube. The fluid chamber includes a release assembly that releases fluid stored in the fluid chamber into the shunt tube. The fluid includes magnetically responsive particles. The packer also includes one or more magnetic field generators that generate one or more magnetic fields that arrest released fluid within the shunt tube by activating the magnetically responsive particles, thereby plugging the shunt tube.

What is claimed is: 
     
         1 . A borehole packer comprising:
 a shunt tube;   a fluid chamber, coupled to the shunt tube, with a release assembly that releases fluid, including magnetically responsive particles, stored in the fluid chamber into the shunt tube; and   one or more magnetic field generators that generate one or more magnetic fields that arrest released fluid within the shunt tube by aligning the magnetically responsive particles, thereby plugging the shunt tube.   
     
     
         2 . The packer of  claim 1 , wherein the one or more magnetic fields are generated by one or more magnets. 
     
     
         3 . The packer of  claim 1 , wherein the release assembly comprises a sensor to sense a remotely-generated signal, the signal initiating release of the fluid when received by the sensor. 
     
     
         4 . The packer of  claim 1 , wherein the one or more magnetic field generators comprise a sensor to sense a remotely-generated signal, the signal initiating generation of the one or more magnetic fields when received by the sensor. 
     
     
         5 . The packer of  claim 1 , wherein the gravel slurry comprises a second set of magnetically responsive particles, and wherein the one or more magnetic fields arrest the gravel slurry by activating the second set of magnetically responsive particles. 
     
     
         6 . The packer of  claim 1 , further comprising a gravel screen, wherein the fluid chamber is external to the screen. 
     
     
         7 . The packer of  claim 1 , wherein the release assembly comprises a check valve that enables the fluid to exit the fluid chamber and prevents the fluid from entering the fluid chamber. 
     
     
         8 . The packer of  claim 1 , wherein the release assembly comprises a piston that forces the fluid out of the fluid chamber during release. 
     
     
         9 . The packer of  claim 1 , wherein the release assembly comprises a collapsible tube that forces the fluid out of the fluid chamber during release in response to pressure external to the collapsible tube that collapses the tube. 
     
     
         10 . The packer of  claim 9 , wherein a hydraulic pump generates the pressure. 
     
     
         11 . The packer of  claim 1 , wherein the release assembly comprises a burstable disk responsive to pressure within the fluid chamber that bursts the disk and enables fluid to exit the fluid chamber. 
     
     
         12 . The packer of  claim 1 , comprising a second shunt tube, wherein the fluid chamber is coupled to the second shunt tube, wherein the release assembly releases the fluid into the second shunt tube, and wherein the one or more magnetic fields arrest released fluid within the second shunt tube by activating the magnetically responsive particles, thereby plugging the second shunt tube. 
     
     
         13 . The packer of  claim 1 , comprising a second fluid chamber sharing the release assembly with the fluid chamber. 
     
     
         14 . A method of performing a gravel packing operation within a borehole comprising:
 releasing fluid comprising magnetically responsive particles into a shunt tube; and   plugging the shunt tube by activating the magnetically responsive particles to arrest the fluid released into the shunt tube.   
     
     
         15 . The method of  claim 14 , wherein releasing the fluid comprises releasing the fluid after gravel transported by a gravel slurry is placed. 
     
     
         16 . The method of  claim 14 , wherein releasing the fluid comprises releasing the fluid as a result of receiving a signal generated from a remote source. 
     
     
         17 . The method of  claim 14 , wherein plugging the shunt tube comprises isolating a zone of an annulus of the borehole. 
     
     
         18 . The method of  claim 14 , wherein plugging the shunt tube comprises generating one or more magnetic fields to activate the magnetically responsive particles. 
     
     
         19 . The method of  claim 18 , wherein generating the one or more magnetic fields comprises generating the one or more magnetic fields as a result of receiving a signal generated from a remote source. 
     
     
         20 . The method of  claim 14 , wherein the gravel slurry comprises a second set of magnetically responsive particles, and further comprising arresting the gravel slurry by activating the second set of magnetically responsive particles using the one or more magnetic fields.