Abstract: The invention comprises a plug assembly for selectively closing and opening a flowway in a tubular conduit. The apparatus includes a seating body having a main passage and adapted to be mounted in the conduit with the main passage in register with the conduit flowway. The seating body defines a seat for receipt of a plug for closing the main passage and supporting a pressure differential across the seat. The apparatus further includes a release control mechanism operative upon the presence of a pressure differential across the seat in excess of a given magnitude to open a bypass passageway bypassing the seat and plug to permit a relatively slow decrease in the pressure differential across the seat.

Abstract: Disclosed are apparatus for gripping and manipulating pipe members, including a plurality of slip carriers mounted on an equal number of carrier actuators. The carrier actuators are arranged within a drive sleeve and constrained by radial T-slot connections to a base ring. Sloped T-slot connections link each of the carrier actuators to the drive sleeve. Longitudinal movement of the drive sleeve in one sense propels the carrier actuators and the slip carriers radially inwardly whereby slips mounted on the slip carriers may grip a pipe member positioned within the drive sleeve; longitudinal movement of the drive sleeve in the opposite sense withdraws the carrier actuators and slip carriers from the pipe member. Cooperating wedging surfaces between each of the slip carriers and the corresponding carrier actuator permits the application of holding or moving force on pipe members in either longitudinal sense.

Abstract: Disclosed are coiled tubing apparatus for operating on wells. A tubing injector head is supported on a mast and is moveable to selected elevations along the mast. The mast includes a lower section maintained in upright orientation, and an upper section which is pivotally joined to the lower section. The injector head may be lowered below the pivot point and the mast folded for transportation purposes. A chain drive maneuvers the injector head in one horizontal direction, and a fluid pressure cylinder maneuvers the injector head in a second horizontal direction generally orthogonal to the first. The chain drive is fitted with a worm gear coupling to positively lock the injector head in position. A height-adjustable level wind tubing guide directs the tubing onto or off of a reel. The base of the apparatus is fitted with a track along which a blowout preventer may be moved for subsequent positioning over a well.

Abstract: An inside blowout preventer assembly for connection into an earth boring drill string has improved features for preventing erosion. The blowout preventer assembly allows downward flow during normal drilling, but prevents upward flow if the flow rate is above a selected amount, to prevent a blowout. The assembly includes a valve body with a longitudinal passage having a throat section. A recess passage intersects the throat section and contains a ball. The ball is movable from the recess passage into the throat section, where it seals against a seat to stop upward flow. An equalizing passage of selected size and configuration extends from the base of the recess passage to the longitudinal passage. The ball is of lesser diameter than the recess passage for allowing downward flow through the recess passage and the equalizing passage. This prevents the ball from being drawn by pressure differential into the throat section during downward flow, reducing turbulence and erosion.

Abstract: Disclosed is a system including two or more fluid pressure piston-and-cylinder assemblies. The cylinders are linked in pairs so that retraction of both piston rods reduces the length of the pair of assemblies to the length of a single assembly. Operation of both pistons in a pair provides an effective stroke twice the length of a single assembly stroke. In a particular embodiment, a double cylinder system is used as a pickup system for elevating equipment along a mast in a well workover rig.

Abstract: Swivel apparatus suspended for handling pipe joints to be added to or taken from a drill string including powered apparatus connected to a cable for raising and lowering the swivel apparatus. The swivel apparatus may comprise an upper stationary section and a lower rotatable tubular section adapted to receive one end of a pipe joint and having a radially movable latch assembly for engagement therewith. The lower section may be provided with cam apparatus movable, relative to the latch assembly, from an inoperative position to an operative position camming the latch assembly from a first position, permitting free entry of the pipe joint end into the lower section, to a second, latching the pipe joint end in the lower section.

Abstract: The invention comprises a packer which seals against a surrounding well conduit. The packer comprises a mandrel which carries a radially extendable seal for engaging the well conduit. A hydraulic actuator is provided for urging the seal to its set position against the well conduit. Once set, the tool is responsive to fluid pressure differentials in the well conduit across the seal in either longitudinal direction to tighten the seal means. The cylinder of the actuator also serves as a guard to overlie and protect the seal in its unset position, while the piston is designed to define auxiliary piston area to reduce the required setting pressure. The seal is set by being extruded both longitudinally and radially over a retainer extending radially outwardly from the mandrel.

Abstract: Diclosed is a connecting assembly for communicating between a first location and a second location lower than the first location, with the two locations separated by a fluid body. A first tube extending between the two locations generally encloses a second tube, and the annular area between adjacent surfaces of the two tubes is sealed toward the second location. The buoyancy of the assembly is selectively controlled by selectively controlling the quantity and density of fluid in the area between the tubes. In an embodiment shown, a marine drilling facility is joined to an underwater well site by a riser with a liner set and sealed therein, and gas-lift pumping is used in controlling buoyancy. In a method, a riser is set between an underwater well site and a marine well operating facility. A first segment of the well may be drilled through the riser. Casing is cemented in the well, and a liner is sealed at its bottom end to the riser.

Abstract: A well tool for use in a tubular well conduit comprising a tool body including at least one radially extendable element for engaging the well conduit, and first and second tool body portions. The tool body portions are operatively associated with the radially extendable element and relatively movable longitudinally toward each other to extend the radially extendable element. Such movement is effected by longitudinal movement of a mandrel assembly which is engageable with the second tool body portion whereby they together form an actuator. The tool further comprises lock means cooperative between the actuator and the first tool body portion to limit movement of the tool body portions away from each other thereby locking the radially extendable element in its extended position. Tightening means associated with the lock means tightens the lock means responsive to fluid pressure acting in a direction opposite the direction of movement of the actuator during setting.

Abstract: Disclosed is releasable plugging apparatus for selectively closing a tubular member to permit fluid pressure buildup therein. When the fluid pressure is then decreased, a sealing device of the apparatus may be released, and the tubular member subsequently opened. Holding apparatus secures the sealing device in place until a compressed spring is permitted to move a piston so as to permit the holding apparatus to release the sealing device. A locking device prevents such movement by the piston until the pressure buildup first moves the piston in the opposite direction to release the locking device and to further compress the spring. The tubular member is thus not unplugged until the fluid pressure is decreased, thereby avoiding a large pressure pulse which might result if the sealing device were released with the fluid pressure at a high value. The embodiments described are particularly applicable for use with hydraulically-operated well tools, such as well packers.

Abstract: A check valve assembly for use in a drill string to prevent reverse flow of drilling fluid through the string while permitting such fluid to be pumped downwardly through the well under normal conditions. The assembly includes: a valve body; a ball valve member, normally located out of the flow path in a side recess; a valve seat located above the valve member and means for controlling the rate of reverse flow of fluid required to move the valve member out of the side recess and against the valve seat.

Abstract: A check valve assembly for permitting unrestricted flow in one direction and limited flow in the reverse direction comprising: a valve body having a longitudinal flowbore therethrough; a seat member carried by the valve body; a closure member carried by the valve body for movement from a normally open position, in which flow through the flowbore is unrestricted, to a closed position engaging the seat member, in which reverse flow through the valve body is prevented; and a reciprocal sleeve member carried by the valve body for movement between a first position, preventing movement of the closure member to its closed position, to a second position, allowing movement of the closure member to its closed position.

Abstract: Well completion apparatus for disposition in a well conduit comprising first and second seal assemblies. The first seal assembly comprises a first cylindrical receptacle member fixed with respect to the well conduit and a first insert member including a first tubular body portion received within the first receptacle member. One of the first members includes a first annular seal coaxial with and sealingly engaged between the first receptacle member and the first tubular body portion. The second seal assembly comprises a second cylindrical receptacle member rigidly adjoining the first tubular body portion and a second insert member including a second tubular body portion received within the second receptacle member. One of the second members includes a second annular seal means coaxial with and sealingly engaged between the second receptacle member and the second tubular body portion.

Abstract: Disclosed is a connecting assembly for communicating between a first location and a second location lower than the first location, with the two locations separated by a fluid body. A first tube extending between the two locations generally encloses a second tube, and the annular area between adjacent surfaces of the two tubes is sealed toward the second location. The buoyancy of the assembly is selectively controlled by selectively controlling the quantity and density of fluid in the area between the tubes. In an embodiment shown, a marine drilling facility is joined to an underwater well site by a riser with a liner set and sealed therein, and gas-lift pumping is used in controlling buoyancy. In the method, a riser is set between an underwater well site and a marine well operating facility. A first segment of the well may be drilled through the riser. Casing is cemented in the well, and a liner is sealed at its bottom end to the riser.

Abstract: Disclosed is pressure responsive holding apparatus for maintaining a first cylindrical element fixed against fluid pressure induced longitudinal movement relative to a second element generally circumscribing the first element. The apparatus includes a gripping device, carried by the first element, and reponsive to fluid pressure between the two elements by moving into anchoring engagement with the second element to hold the first element fixed relative to the second element with force which increases as the fluid pressure increases. In the embodiment shown, the holding apparatus is used to retain a bypass passage through a well packer set in a well conduit closed by preventing fluid pressure from raising a mandrel assembly within the packer body to open the bypass passage.

Abstract: Disclosed is a retrievable, weight set well packer which may be tightened in set configuration by rotation of the tubing string, and which may be released from set configuration by longitudinal movement of the tubing string. Locking means maintain the packer set when the tubing string is raised slightly to open a bypass between the tubing string and the set packer. Continued raising of the tubing string releases the locking means to permit the packer to be retrieved. Dual opposed spreader cones keep the packer set against well pressure differentials acting from either above or below the packer. Pressure responsive means are also employed to increase the forces anchoring the tubing string against movement to open the bypass as differential well pressures tend to so move the tubing string.

Abstract: Disclosed is an anchoring assembly for anchoring well equipment within a surrounding well conduit. In one form of the invention, the anchoring assembly is specifically described for use as an hydraulically set, retrievable liner hanger. A modified form of the invention describes the anchoring assembly employed with a seal to function as an hydraulically set, retrievable well packer.

Abstract: The assembly is supported and operated by a tubing string and includes an hydraulically set packer carrying a production screen and a removable gravel pack apparatus. The packer is set, gravel is packed about the screen and the gravel pack apparatus is then removed from the set packer by disengaging a pin and slot connection. The gravel pack apparatus and attached screen may be subsequently re-engaged with the packer for regraveling. The packer is equipped with resilient seal means and a plurality of radially movable anchoring slips which are set in sealing and anchoring engagement, respectively, with a surrounding well conduit by an hydraulic setting mechanism. The gravel pack apparatus cooperates with the set packer to form a series of separate, axially extending, flow passages which may be selectively opened or closed.

Abstract: A check valve assembly for use in a drill string to limit reverse flow of drilling fluid through the string while permitting such fluid to be pumped freely into the well under normal conditions. The assembly may include: a valve body having a longitudinal flowbore therethrough; a valve seat at one end of the flowbore; a pair of inclined cylindrical recesses in the valve body communicating with the flowbore; and a ball member normally disposed in either one of the recesses and movable into the flowbore for sealing engagement with the seat in response to a predetermined rate of reverse flow through the flowbore.

Abstract: Disclosed is an elevator for handling pipe with enlarged ends by gripping the end of the pipe with the enlargement between two hinged arm pieces. In the specific embodiment shown, one arm piece fits into the end of the pipe with enlarged end in the form of a collar, and cooperates with a C-shaped receptacle which is fixed to the end of the other arm piece, and which fits around the pipe and catches the pipe collar to prevent the pipe from separating from the first arm inserted into the pipe end. A spring-actuated lock prevents the arms from opening and releasing the pipe.