Abstract: A method and system for recovering fluids from a hydrocarbon-bearing subsurface formation includes a first tubing string run into the well and a second tubing string run within the first tubing string. The annulus between the first and second tubing strings is sealed above a liquid level in the well and at least one fluid passageway is provided between the first and second tubing strings at a location between the liquid level and adjacent the annulus seal. The difference of the liquid head between the inside of the second tubing string opposite the at least one fluid passageway and the outside of the second tubing string (i.e. the first and second tubing string annulus) provides the casing annulus-to-tubing differential pressure that forces gas above the annulus fluid level to pass through the at least one fluid passageway and re-enter the fluid stream in the second tubing string.

Abstract: A grease injection control head for maintaining a seal about a wire performing wireline operations in a well. A tubular body includes a grease injection port for injecting grease for counteracting pressure in the well with a vent port above the injection port for venting fluids. A plurality of tubular members are provided in the body positioned between the injection port and the vent port. Each member includes a close fitting longitudinal bore for passage of a wireline for providing a grease pressure seal. The members are telescopically and sealably joined to adjacent members. The members include an enlarged cavity about the bore at each end for providing a turbulent grease chamber between adjacent members for distributing the pressure drop along the body for reducing loading on the wire and friction with a minimum length body. The length of a longitudinal bore relative to the longitudinal length of a chamber is no greater than 5:1.

Abstract: An apparatus for measuring bottom hole conditions such as pressure in the tubing of a well including a locking and sealing sub to lock into and seal against the interior of the tubing, an isolation valve connected in the sub and a measuring instrument connected to the valve for measuring conditions in the tubing. The isolation valve has a bore with an annular seat in the bore and side ports leading into the bore below the seat. A valve element is longitudinally movable in the valve between an open position below the ports and a closed position against the seat and includes an elongate mandrel having a backup shoulder. A latch mechanism initially holds the valve in the open position and includes a collet member initially engaging the mandrel and holding the valve element in the open position and the collet is held in a latched position by a spring loaded backup shoulder.

Abstract: A circulating (kill) valve for hot, high pressure wells includes a valve assembly to be positioned in an open-ended tubular-shaped side-pocket housing of a mandrel connected into a well tubing string. The valve assembly includes an open-ended cylindrical valve body provided with an interior sealing seat and spaced-apart side openings. A valve element is arranged within the valve body and is urged by unbalanced pressures to the open or closed position depending on the direction of the pressure imbalance. In the closed position a sealing surface on the exterior of the valve element engages and seals with the lower interior sealing seat of the valve body. A ported access to the inner well string pressure permits that pressure to urge the valve element to the closed position. Such pressure may be overcome by pressure imbalance when fluid pressure exterior of the tubing string forces the valve element upwardly from its seat.

Abstract: In a well lock and a locking nipple for use in a tubing in a well in which the locking nipple includes first and second recesses and a stop shoulder and the well lock includes a locking housing carrying first and second locking dogs, seal means on the exterior of the housing for sealing with the nipple, a resiliently outwardly urged locator having a shoulder for engaging the stop shoulder, a mandrel telescopically positioned in the housing, a locking shoulder on the mandrel locking the first locking dogs in the first recess and means on the mandrel engaging the second locking means for preventing unlocking of the first locking dogs if pressure is applied to the seal to move the housing upwardly, the improvement in which the distance between the bottom of the first recess and the locking shoulder is greater than the distance between the bottom of the first locking dogs and the locator shoulder whereby the first locking dogs lock the device against upwardly and downwardly forces and the locator is retracted out

Abstract: A well safety valve adapted to be positioned in a well tubing and close on either a predetermined high tubing pressure or a predetermined low tubing pressure. The valve closure member in the valve body moves between an open and closed position in response to longitudinal movement of a tubular member. The tubular member has an open bore for alignment with the bore of the well tubing to provide straight through flow through the safety valve. In addition, the tubular member has a plurality of telescoping sections and releasable and resettable locking means normally securing the plurality of sections together. A predetermined high tubing pressure or a predetermined low tubing pressure acting on the tubular member causes the valve to close.

Abstract: A well locking device and method of operation including a well lock and a landing nipple for locking well equipment in the production string of oil and/or gas wells. The well lock includes two sets of locking dogs, one of which locks the well lock in the landing nipple and holds against loads either from above or below the lock. The second set of locking dogs prevents the release of the well lock from the nipple when a pressure differential exists across the lock. A locking nipple includes first and second recesses and a stop shoulder and the coacting well lock includes a housing carrying first and second locking dogs in which the vertical spacing of the first and second locking dogs is less than the vertical distance between the tops of the first and second recesses. A seal is positioned on the exterior of the well lock housing and adapted to seal in the locking nipple, and locating means are provided on the housing for engaging the stop shoulder of the nipple.

Abstract: A well safety valve for controlling the fluid flow through a well tubing in which the valve is biased closed. When fluid control pressure is supplied from the well surface, the valve is opened, but the valve closes when the control pressure exceeds a predetermined value. The tubular member controlling the actuation of the valve member includes a first upper and a second lower telescoping section with releasable locking means normally securing the telescoping sections together. A stop shoulder is positioned in the path of movement of the second section in the opening direction for actuating the release of the locking means when the control fluid force exceeds said predetermined value, and the second telescoping section is moved in a closing direction for closing the valve member when the locking means is released. The locking means may be either a shear pin or a resettable lock.

Abstract: A method of and apparatus for measuring bottom hole pressure in the tubing of a well by installing an isolation assembly in the tubing by a locking and sealing device in which the assembly includes first and second ports in communication between the interior of the assembly and the interior of the tubing. A sensor prong is releasably installed in the isolation assembly and includes a pressure measuring instrument releasably connected thereto. After the well is flowed through the first port, the first port is closed by actuation of the prong, and pressure measurements are taken through the second port by the pressure measuring instrument. After completion of the measurement, the measuring instrument may be released from the prong and retrieved. The prong is thereafter retrieved. The first port, which is larger than a second port, is initially releasably held open.

Abstract: A mandrel for use in a well tubing in which the mandrel body has an open bore for alignment with the well tubing and a sidepocket offset from the open bore for receiving flow control devices. An integrally forged sub is welded to the top of the body and includes an actuating shoulder angularly spaced from the axis of the offset pocket a predetermined amount and a guide surface is positioned below the shoulder and directed upwardly towards the shoulder. A deflector guide is positioned in the offset bore above the pocket and includes a pair of rails forming a guide path which allows the entrance of flow control devices in the pocket but prevents the entrance of open bore tools into the guide path. The deflector guide and the pocket are telescopically secured to each other by coacting flat surfaces for insuring transverse alignment therebetween and include abutting coacting shoulders for maintaining proper axial spacing between the locking lug and the pocket.

Abstract: A well safety valve for controlling the fluid flow through a well tubing in which the valve closure member is controlled by a longitudinal movable tubular member which opens and closes the valve, can lock the valve in an open position, can telescopically collapse to avoid damage to the valve, and can be reset either manually or automatically. The tubular member includes first and second telescoping sections which are releasably locked together in an intermediate extended position for normally opening and closing the valve on movement of the tubular member. The releasable locking means is constructed to release upon the application of a predetermined force less than a force sufficient to cause damage to the valve whereby on application of an excessive force the sections will telescope towards each other preventing damage to the valve.

Abstract: A fluid injection valve for use in a well tubing having an opening therein in which the valve controls the flow of fluid flowing between the outside of the tubing and the inside of the tubing through the opening. A spring-loaded relief valve element yieldably closes a port in the valve against the flow of fluid and a closed flexible pressurized chamber is provided with one end being movably positioned against the valve element. The exterior of the chamber is exposed to the valve outlet pressure so that in the event that the outlet pressure drops below a predetermined amount, the chamber will expand and act against the valve element to close the valve. The chamber may be a bellows and the cross-sectional area of the chamber is preferably greater than the cross-sectional area of the port to provide a closure force sufficient to overcome a hydrostatic head outside of the tubing.

Abstract: In a well safety valve for controlling the fluid flow through a well tubing in which the valve closure means is controlled by a longitudinal movable tubular member, the improvement of a fail-safe mechanism for avoiding damage to the valve by avoiding excessive operating forces. The tubular member includes first and second telescoping sections which are releasably locked together in an intermediate extended position for normally opening and closing the valve on movement of the tubular member. The releasable locking means is sized to release upon the application of a predetermined force less than a force sufficient to cause damage to the valve whereby upon application of an excessive force the sections will telescope towards each other preventing damage to the valve. Tool engaging means are provided on the second telescoping section for repositioning the tubular sections relative to each other or for extending the second section for locking the valve closure member in the open position.