Hydraulically operated and released isolation packer

A hydraulically operated isolation packer adapted for use in sealing a hydrocarbon production casing, comprising:

• a mandrel having a bore therethrough for carrying hydraulic fluids, and movable within said casing to a desired position for isolating regions therein;
• elastomeric means encircling said mandrel and adapted to radially expand in response to an axial compressive force applied thereto for sealing said mandrel to said production casing;
• a first piston releasably fixed to said mandrel;
• a second piston responsive to a first fluid pressure for moving from a rest position to a position for applying said axial compressive force for expanding said elastomeric means;
• means for engaging said second piston to said first piston so that said elastomeric means remains expanded in a sealing relationship with said production casing;
• and
• means responsive to a second pressure for operating said first piston and for releasing said first piston from said mandrel, and thereby allowing said second piston to be removed from compressive engagement with said elastomeric means.

A hydraulically operated isolation packer adapted for use in sealing a hydrocarbon production casing, comprising:

• a mandrel having a bore therethrough for communicating hydraulic fluid, said mandrel having a fluid port in a sidewall thereof;
• a first cylinder piston releasably attachable to said mandrel, said first piston including engaging teeth on an inside surface thereof;
• a second piston slideable over said mandrel and disposed generally between said mandrel and said first piston, said second piston having outer engaging teeth;
• a ratchet ring having inner and outer teeth engageable respectively with the teeth of said second piston and said first piston, the teeth of said ratchet ring and of said first and second piston being oriented so as to allow said second piston to move in one direction with respect to said first piston, but preventing movement thereof in an opposite direction;
• means for releasably fixing said second piston to said first piston;
• seal means for sealing said first and second pistons together, and for sealing said first and second pistons to said mandrel to thereby form a chamber about said fluid port;
• an annular elastomeric band encircling said mandrel and adapted to radially expand in response to an axial compressive force applied thereto to thereby seal said mandrel to said production casing;
• and
• means connected to said second piston and responsive to the movement thereof in said one direction for applying said compressive force to said elastomeric band.

A hydraulically operated isolation packer adapted for use in sealing a hydrocarbon production casing, comprising:

• a mandrel having a bore therethrough for communicating hydraulic fluid, said mandrel having a reduced diameter part defining a sidewall, and a fluid port in said sidewall;
• a cylindrical shell fittable around the reduced diameter part of said mandrel, and having an upper flange;
• an upper thimble threadably engageable with said mandrel and engageable with the upper flange of said shell for fixing said shell to said mandrel, said upper thimble having a tapered surface;
• an annular elastomeric band disposed around said shell and including an upper and lower annular tapered edge, said upper annular tapered edge engaging the tapered surface of said upper thimble;
• a first cylinder piston fixed to said mandrel by a shearable device, said first cylinder piston including internal annular engaging teeth angled downwardly;
• a second piston encircling the reduced diameter part of said mandrel and disposed generally between said mandrel and said first piston, said second piston including a shearable connection to said first piston, and further including downwardly angled engaging teeth formed on an outer surface thereof;
• a ratchet ring disposed between said first piston and said second piston, and including inner and outer upwardly angled engaging teeth engaging with the respective engaging teeth of the second piston and said first piston to thereby provide a ratchet movement of said second piston with respect to said first piston;
• a lower thimble fixed to an upper part of said second piston, said lower thimble having a tapered surface engageable with a tapered annular edge of said elastomeric band;
• and
• seal means for sealing said first and second pistons together and about said fluid port to thereby form a chamber such that in response to a first fluid pressure in said chamber the shearable connection between said first and second pistons is released and said second piston is moved in a direction for causing compression of said elastomeric band, and such that in response to a second greater fluid pressure in said chamber the shearable device between said first piston and said mandrel is released and said first piston is allowed to move in a direction opposite that of said second piston so that said elastomeric band is allowed to relax to thereby permit said packer to be moved in the casing.

A method for setting a packer in a production casing, comprising the steps of:

• fixing the packer to a tubing string so as to communicate fluid pressure from the tubing string to the packer;
• lowering the tubing string and the packer fixed thereto to a desired location within the casing;
• pressurizing the tubing string with a hydraulic fluid to a first pressure for ratcheting a locking arrangement and causing an elastomeric element of said packer to expand and seal and lock said packer in a sealed condition in the casing;
• removing the first pressure from the tubing string;
• pressurizing the tubing string with a hydraulic fluid to a second higher pressure for releasing said locking arrangement and the seal of said packer from the casing;
• and
• withdrawing the tubing string and said packer fixed thereto from the casing.

A hydraulically operated isolation packer adapted for use in sealing a hydrocarbon production casing, comprising:

• a mandrel having a bore therethrough for carrying hydraulic fluids;
• elastomeric means encircling said mandrel and adapted to expand in response to a pressure applied thereto for sealing said packer within said production casing;
• a piston responsive to a first fluid pressure in said mandrel for moving said piston such that said elastomeric means is expanded;
• and
• means comprising a ratchet arrangement for allowing one-way movement of said piston for locking said piston such that said elastomeric means remains expanded, said locking means being responsive to a second fluid pressure for releasing said piston to thereby allow said elastomeric means to contract and permit movement of said packer within said casing.

A method for setting a packer in a production casing, comprising the steps of:

• fixing the packer to a tubing string so as to communicate fluid pressure from the tubing string to the packer;
• lowering the tubing string and the packer fixed thereto to a desired location within the casing;
• pressurizing the tubing string with a hydraulic fluid to a first pressure for causing an elastomeric element of said packer to expand and seal said packer and set said packer in the casing;
• removing the first pressure from the tubing string;
• pressurizing the tubing string with a hydraulic fluid to a second higher pressure for releasing the seal of said packer from the casing;
• pressurizing the tubing string with the second pressure to operate another piston for releasing the seal of the elastomeric element to the casing;
• and
• withdrawing the tubing string and said packer fixed thereto from the casing.