Abstract: The present invention comprises a method and apparatus especially suitable for hydraulically releasing from a screen on a circulation-type gravel pack job. The releasing tool of the present invention comprises a tubular case by which the tool is secured to a gravel packer thereabove, and a gravel screen is secured thereto therebelow, the case having disposed within a collet sleeve assembly shouldering on the top of the case and including a plurality of collets extending downwardly into the case, the collets being radially outwardly biased into engagement with the case by the lower end of a releasing mandrel disposed within the collet sleeve. A ball seat at the top of an axial bore extending through the releasing mandrel permits the seating of a ball and downward movement of the releasing mandrel inside the collet sleeve, removing the outward bias against the collets and permitting withdrawal of the collet sleeve and releasing mandrel from the case and attached screen therebelow.

Abstract: A retrievable well packer includes a packer mandrel with an expandable packing element disposed about the mandrel. Upper and lower shoes are received about the mandrel above and below the expandable packing element for compressibly engaging the packing element. A slip assembly is received about the mandrel for anchoring the packer within the well bore. Upper and lower wedges are received about the mandrel above and below the slip assembly for wedging the slip assembly radially outward upon longitudinal compression of the packing element. The mandrel is nonrotatably connected to each of the upper and lower shoes and upper and lower wedges for preventing rotation of those components relative to the mandrel in the event the packer must be milled out of a well bore. The mandrel is initially releasably longitudinally locked relative to the lower wedge by a releasing collet attached to a lower end of the mandrel and having radially outward extending lugs received within a groove of the lower wedge.

Abstract: A liner seal for use in a tool string for sealing above a gravel pack around a liner screen. The liner seal is originally positioned in the tool string between the liner screen and a release mechanism. The release mechanism is a pressure actuated, non-rotational type having collets engaged with a portion of the liner seal. Gravel is packed around the liner screen, and the release mechanism is actuated. Setting weight on an outer sleeve of the liner seal downwardly moves the outer sleeve with respect to an inner sleeve attached to the liner screen. This relatively converging movement of the outer and inner sleeves radially outwardly displaces a seal member into sealing engagement with the well bore. A shear pin is included so that a predetermined load is required for downwardly moving the outer sleeve. A slip is provided to prevent upward movement of the outer sleeve, thus preventing disengagement of the seal member with the well bore.

Abstract: A method of gravel packing a well formation and an apparatus usable therefor. The method of gravel packing includes mixing a slurry formed by solids suspended in a gelled carrier fluid with a breaker fluid at a subterranean position above the well formation to be packed, whereby the gel is broken into a low viscosity fluid which is pumped along with the solids to the formation for packing thereof. The apparatus includes a mixing valve positioned in a tool string above a packer, crossover tool and liner screen. When the tool string is run into the well, the mixing valve defines said subterranean position. The breaker fluid is spotted in an annulus between the tool string and well bore, above the packer. The gelled slurry is pumped down the tool string to the mixing valve, and the breaker fluid is introduced through the mixing valve into the tool string for mixing with the gel.

Abstract: The present invention comprises a retrievable gravel packer for circulation and squeeze type gravel packing. The gravel packer includes a compression-set packer element, a J-slot assembly to releasably maintain the gravel packer in an unset mode, a ratchet assembly to releasably lock the gravel packer in a set mode, an intake passage to receive fluid from a tubing string, a return passage to receive fluid from a gravel screen below the gravel packer, a circulation passage extending from the exterior of the gravel packer to intake passage, a closeable crossover assembly to receive fluid from the return passage; a first check valve to prevent back flow back to the intake passage from the interior of the interior of a gravel screen therebelow, a second check valve adapted to selectively open the intake passage to the circulation passage, and a check valve release for removing said second check valve means from the junction of the intake and circulation passages.

Abstract: The present invention relates to a weight-set single-zone gravel packer which may be left in place after gravel packing attached to the screen as a production packer. The gravel packer includes a compression-set packer element, ratchet means to releasably lock the gravel packer in a set mode, intake passage to receive fluid from a tubing string, a return passage to receive fluid from the interior of a gravel screen below the gravel packer; closeable crossover means to transmit fluid from the return passage to the wellbore annulus above the gravel packer; first check valve means to prevent flow down to the gravel screen through the return passage; and second check valve means adapted to selectively connect the return passage with the outside of the gravel packer; and J-slot means for selectively disconnecting the crossover means and tubing string from the gravel packer.