Hydrostatic-set open hole packer with electric, hydraulic and/or optical feed throughs

Abstract

Devices and methods are described for disposing electric, hydraulic and/or optical cables or conduits axially through a hydrostatically-set packer mechanism. Radial fluid communication is also provided through the inner mandrel so that the packer mechanism may be set using hydrostatic pressure within the flowbore. Feed-through paths for the cables or conduits isolate the cables/conduits from fluid pressure as well as axial or torsional tensile forces.

1 . A packer assembly for creating a fluid seal within a wellbore comprising: 
 a tubular central mandrel having an upper end and a lower end, defining a central flowbore and having an outer radial surface;    a packer element surrounding the tubular mandrel, the packer element being moveable between a radially reduced unset position and a radially expanded set position;    a hydrostatic setting assembly for selectively causing the packer element to be set in its expanded position, the hydrostatic setting assembly comprising:    a) a radial fluid communication port for communicating hydraulic fluid pressure within the central flowbore through the tubular mandrel to its outer radial surface;    b) a piston element for receiving fluid pressure from the central flowbore and applying said fluid pressure to urge the packer element toward its set position; and    a cable feed-through path defined within the tubular mandrel to allow a cable to pass from the upper end of the mandrel to the lower end of the mandrel.    
   
   
       2 . The packer assembly of  claim 1  wherein the cable feed-through path comprises a longitudinal drilled hole in the mandrel.  
   
   
       3 . The packer assembly of  claim 1  wherein the setting piston is releasably secured to the central mandrel by a locking dog.  
   
   
       4 . The packer assembly of  claim 1  wherein the fluid communication port is angularly offset from the feed-through path about the circumference of the central mandrel.  
   
   
       5 . The packer assembly of  claim 1  wherein the setting assembly further comprises an actuating sleeve that lies within the central flowbore and is moveable between a first position, wherein fluid communication through the radial fluid communication port is blocked, and a second position, wherein the actuating sleeve does not block the port.  
   
   
       6 . The packer assembly of  claim 5  wherein the actuating sleeve presents an engagement shoulder that is shaped and sized to be contacted by a suitable shifting tool for movement of the actuating sleeve from its first to its second position.  
   
   
       7 . The packer assembly of  claim 5  wherein: 
 the setting piston is releasably secured to the central mandrel by a locking dog; and    wherein movement of the actuating sleeve from the first to the second position releases the setting piston from the central mandrel.    
   
   
       8 . The packer assembly of  claim 1  wherein the packer element comprises a composite packer element for use in creating a fluid seal within an uncased borehole.  
   
   
       9 . A system for disposing a cable axially through a packer device that is set hydrostatically, the system comprising: 
 a central tubular mandrel defining a flowbore to contain hydrostatic pressure;    a packer element carried by the central mandrel, the packer element being moveable between an unset position and an axially compressed set position;    a setting mechanism for moving the packer element to its set position in response to hydrostatic pressure within the flowbore; and    a feed-through path defined axially through the mandrel, the feed-through path retaining a cable in isolation from external fluid pressures.    
   
   
       10 . The system of  claim 9  further comprising: 
 a radial fluid communication port for transmitting hydrostatic fluid pressure from the flowbore to an actuation chamber located radially outside of the central mandrel; and    wherein the fluid communication port is angularly offset from the feed-through path about the circumference of the central mandrel.    
   
   
       11 . The system of  claim 9  wherein the feed-through path comprises a longitudinal drilled hole in the central mandrel.  
   
   
       12 . The system of  claim 10  wherein the setting mechanism further comprises a piston element retained within the actuation chamber for receiving fluid pressure from the central flowbore and applying said fluid pressure to urge the packer element toward its set position.  
   
   
       13 . The system of  claim 12  wherein the piston element is releasably secured to the central mandrel.  
   
   
       14 . The system of  claim 13  wherein the piston element is releasably secured to the central mandrel by a locking dog.  
   
   
       15 . The system of  claim 9  wherein the setting mechanism further comprises an actuating sleeve that lies within the flowbore and is moveable between a first position, wherein fluid communication through the radial fluid communication port is blocked, and a second position, wherein the actuating sleeve does not block the port.  
   
   
       16 . The system of  claim 15  wherein the actuating sleeve is releasably retained in the first position by a shear pin.  
   
   
       17 . A method of disposing a cable axially through a hydrostatically-set packer device, the method comprising the steps of: 
 forming a cable pass-through path within a central mandrel of the packer device;    disposing a cable along the cable pass-through path; and    securing an end nut upon the cable to secure the cable to the central mandrel.    
   
   
       18 . The method of  claim 17  wherein the step of forming a pass-through path within the central mandrel comprises drilling a longitudinal hole within the central mandrel that is shaped and sized to accommodate the cable.