Hydraulically set and released bridge plug

A well tool apparatus, comprising:

• a mandrel means having an operating fluid passageway disposed therein;
• a releasable coupling means adapted to be releasably connected to said mandrel means, said coupling means having a radially inward extending shoulder defined thereon which faces in a first longitudinal direction;
• and
• hydraulically actuatable release means, including:
• a spring collet concentrically received about said mandrel means and having a plurality of longitudinally extending spring fingers, each of said spring fingers including a radially outward extending shoulder means facing in a second longitudinal direction opposite said first longitudinal direction for engaging said radially inward extending shoulder of said coupling means and for thereby providing a latched connection between said coupling means and said mandrel means, said spring collet having an annular base at a first end thereof, with said spring fingers having first ends attached to said base and having second ends located away from said base and collectively defining a second end of said spring collet, said spring collet being held in place longitudinally relative to said mandrel means between first and second enlarged diameter portions of said mandrel means engaging said first and second ends, respectively, of said spring collet;
• a power sleeve concentrically and slidably received about said mandrel means and having a differential area piston defined thereon which is in fluid communication with said operating fluid passageway of said mandrel means, said power sleeve being longitudinally movable between first and second positions relative to said mandrel means in response to a change in fluid pressure within said operating fluid passageway;
• and
• said power sleeve having a cam surface means defined thereon for engaging said spring fingers of said spring collet and for biasing said spring fingers radially inward to release said latched connection between said coupling means and said mandrel means as said power sleeve moves from its said first position to its said second position.

A bridge plug apparatus, comprising:

• a mandrel means having an operating fluid passageway disposed therein, and having a bypass passage disposed therethrough;
• an annular packer means disposed about said mandrel means;
• power piston means, operatively associated with said mandrel means and said packer means, for longitudinally compressing and radially expanding said packer means to seal said packer means against a well bore in response to a change in fluid pressure in said operating fluid passageway;
• a releasable coupling means, having an upper end adapted to engage a tubing string and having a lower portion adapted to be releasably connected to said mandrel means;
• and
• a power sleeve concentrically and slidably received about said mandrel means and having a differential area piston defined thereon which is in fluid communication with said operating fluid passageway of said mandrel means, said power sleeve being longitudinally movable between first and second positions relative to said mandrel means in response to a further change in fluid pressure within said operating fluid passageway after said packer means is expanded by said power piston means, said power sleeve including:
• a first valve portion defined thereon for closing said bypass passage of said mandrel means as said power sleeve moves from its said first position to its said second position;
• a second valve portion defined thereon for trapping fluid under pressure in a portion of said operating fluid passageway communicated with said power piston means as said power sleeve moves from its said first position to its said second position;
• and
• a release means defined thereon for releasing said releasable coupling means from latched connection to said mandrel means as said power sleeve moves from its said first position to its said second position.

The apparatus of claim 19, further comprising:

• one-way check valve means, disposed in said operating fluid passageway of said mandrel means, for allowing increases in fluid pressure in said well bore above said packer means to be transmitted to said portion of said operating fluid passageway communicated with said power piston means;
• wherein said mandrel means includes a first lateral port disposed therethrough communicating said operating fluid passageway above said check valve means with an exterior of said mandrel means, and said mandrel means includes a second lateral port disposed therethrough communicating said operating fluid passageway below said check valve means with said exterior of said mandrel means;
• and
• said power sleeve includes an enlarged internal diameter surface defining an annular cavity which communicates said first and second lateral ports of said mandrel means when said power sleeve is in its said first position relative to said mandrel means.