Method and apparatus for hydraulically firing a perforating gun below a set packer

A packer positionable along a tubing string in a subterranean well bore and above a pressure responsive device, the packer adapted for sealing the annulus between the tubing string and sides of the well bore and including (a) a tubular packer body structurally interconnecting an upper portion of the tubular string and a lower portion of the tubular string said tubular packer body having a cylindrical interior surface defining a packer bore diameter, (b) one or more elastomeric packer sealing elements radially exterior of the packer body for sealing engagement with the sides of the well bore, and (c) an exterior packer housing, the packer further comprising:

• a first flow path positioned radially between the tubular packer body and both the exterior packer housing and the packer sealing elements for communicating pressure from the annulus above the packer sealing elements to the pressure responsive device;
• a second flow path in fluid isolation from the first flow path and positioned radially between the tubular packer body and both the exterior packer housing and the packer sealing elements, and extending axially from above to below the packer sealing elements, for transmitting pressure between the annulus below the packer and the annulus above the packer when the packer is in its unset position;
• and
• a shiftable closure member responsive to the setting of said packer for automatically sealing the upper end of the second flow path from annulus pressure when the packer is set within the well bore.

The method of actuating a pressure responsive device positioned below a packer set within a subterranean well bore, the packer including a tubular packer body structurally interconnecting an upper portion of the tubing string and a lower portion of the tubing string and packer sealing elements radially exterior of the packer body for sealing the annulus between the tubing string and the sides of the well bore, the method comprising the steps of:

• forming an annular flow path around the packer sealing elements positioned between the packer body and the packer sealing elements;
• forming a second flow path through the packer having its upper end adjacent to the annulus pressure above the packer sealing elements and having its lower end below the packer sealing elements, the flow path being positioned within the annular flow path;
• interconnecting a flow line positioned exterior of the lower portion of the tubular string for establishing fluid communication between the lower end of the second flow path and the pressure responsive device;
• filling said second flow path and said flow line at the surface with a selected fluid;
• applying the pressure of fluid in the annulus above the packer sealing elements to said selected fluid;
• and
• generating an activating signal to actuate the pressure responsive device by selectively controlling pressure in the annulus above the set packer, through the set packer along the second flow path, and through the flow line to the pressure responsive device.

A packer positionable along a tubing string in a subterranean well bore interior of a casing and above a perforating gun having a fluid pressure responsive firing head, the packer adapted for sealing the annulus between the tubing string and the casing and including (a) a tubular packer body structurally interconnecting an upper portion of the tubing string having an upper tubing bore diameter of at at least 21/4" and a lower portion of the tubing string having a lower tubing bore diameter of at 21/4", and (b) one or more packer sealing elements radially exterior of the packer body for sealing engagement with the casing, the packer further comprising:

• the tubular packer body having a cylindrical interior surface defining a bore diameter of at least 21/4", such that the packer has substantially full bore capability for transmitting production fluids and/or equipment through the tubing string and the packer;
• an annular flow passage surrounding said tubular packer body and bypassing said packer sealing elements when said packer is unset;
• means responsive to setting of said packer for closing one end of said annular flow passage;
• one or more tubular-shaped flow conduits each extending axially from above to below the packer sealing elements and positioned within said annular flow passage for transmitting fluid pressure signals to the firing head of the perforating gun;
• means for filling said flow conduits with a selected fluid prior to insertion of the packer in the well;
• and
• means for subjecting said selected fluid to the annulus pressure above the packer sealing elements.

A packer positionable along a tubing string in a subterranean well bore and above a perforating gun having a fluid pressure responsive firing head, the packer adapted for sealing the annulus between the tubing string and sides of the well bore and including (a) a tubular packer body structurally interconnecting an upper portion of the tubular string and a lower portion of the tubular string and body having a cylindrical interior surface defining a packer bore diameter, (b) one or more elastomeric packer sealing elements radially exterior of the packer body for sealing engagement with the sides of the well bore, and (c) an exterior packer housing, the packer further comprising:

• a first flow path positioned radially between the tubular packer body and both the exterior packer housing and the packer sealing elements for communicating pressure signals from the annulus above the packer sealing elements to the firing head of the perforating gun;
• said first flow path being filled at the surface with a selected fluid;
• means for applying the annulus fluid pressure to said selected fluid;
• a second flow path in fluid isolation from the first flow path and positioned radially between the tubular packer body and both the exterior packer housing the packer sealing elements, and extending axially from above to below the packer sealing elements, for transmitting pressure between the annulus below the packer and the annulus above the packer when the packer is in its unset position;
• and
• a closure member for automatically sealing at least one end of the second flow path from annulus pressure above the packer sealing elements when the packer is set within the well bore.

The method of firing a perforating gun positioned below a packer set within a well bore, the packer including a tubular packer body structurally interconnecting an upper portion of the tubing string and a lower portion of the tubing string and elastomeric packer sealing elements radially exterior of the packer body for sealing the annulus between the tubing string and the sides of the well bore, the method comprising:

• forming a flow path through the packer and disposed at its upper end adjacent to the annulus pressure above the packer sealing elements and having its lower end below the packer sealing elements, the flow path being positioned radially between the packer body and the packer sealing elements;
• interconnecting a flow line positioned exterior of the lower portion of the tubular string for establishing fluid communication between the lower end of the flow path and the perforating gun;
• filling said flow path and said flow line at the well surface with a selected fluid;
• transmitting the annulus pressure above the set packer to said selected fluid;
• and
• providing hydraulically-responsive gripping members positioned axially above the packer sealing elements and radially outward of the flow line for gripping engagement with the casing;
• forming a second flow path for communicating pressure from the annulus below the packer sealing elements to the gripping members;
• and
• positioning at least one tubular conduit within the second flow path to form the first flow path.