Abstract: Apparatus for extracting core samples from the side walls of a subterranean well bore comprises an axial force generating tool insertable into the well with such tool carrying a stationary support rod and the movable element of such tool producing a movement of a housing surrounding the stationary support rod. Annular core forming tools are mounted on plural anvil plates disposed on sides of the stationary support rod and such tools are moved into penetrating relationship with the well bore side wall through association with a linkage between the movable housing, the anvil plates, and the stationary support rod. The movement of the axial force generating element is opposed by a resistance element. A limit to the maximum force applied to the core forming tools is provided by a shearable element series connected in the stationary support rod.

Abstract: A running tool for a hydraulically set packer, hanger, or the like, having expandable slip elements held in a retracted position by an actuating sleeve during run-in, employs an annular piston to hold the actuating sleeve in a fixed locked position relative to the tubular body portion of the running tool, thus preventing inadvertent setting of the tool due to impacts received during the run-in of the tool. When the slips are positioned at their desired location in the well, an increase in fluid pressure applied to the tubular body portion of the running tool will effect an upward movement of the annular piston, shearing a shear screw which has held the piston during the run-in operation, releasing a positive lock engaged with the slip actuating sleeve, and effecting upward movement of the actuating sleeve to release the slips.

Abstract: A concentric insulating tubular conduit member for use in forming a conduit string, such as a tubing string in a subterranean well, is disclosed. Each individual concentric conduit comprises an outer tubing and an outwardly flared inner tubing welded to the outer tubing at the end of the flared section. The inner tubing member is formed from an initially straight cylindrical member having enlarged ends and, when outwardly flared, the flared ends, although stretched, have a thickness at least equal to the nominal thickness of the inner tubular member. Insulation may be contained within the annular cavity between the inner and outer tubing members and between inner and outer coupling members at the juncture between adjacent tubing sections.

Abstract: A well perforating apparatus includes an underbalancing valve for opening ports in a tubing string immediately subsequent to the firing of a perforating gun, and comprises a hollow conduit having at least one pair of axially aligned, and radial holes traversing the wall of the conduit. A frangible member has its end portions slidably and sealably mounted in such holes and is therefore disposed transversely to the path of a detonating bar which is dropped to initiate the firing of the perforating gun. Upon breakage of the frangible member, the ends of the bar are forced inwardly out of the holes by the fluid pressure differential existing between the interior and exterior of the conduit due to the underbalanced fluid pressure condition achieved in the tubing string prior to firing the perforating gun.

Abstract: A method and apparatus for inserting a seal stack in a seal bore defined by a well tool located downhole where ambient conditions would cause radial swelling of the seal stack. The seal stack is mounted at the surface in a confined space defined between a mandrel and a constraining sleeve shearably connected to the mandrel. Upon run-in of the mandrel to enter the seal bore, the constraining sleeve engages an upwardly facing surface surrounding the entrance to the seal bore which prevents further downward movement of the constraining sleeve. Application of a downward force effects the shearing of the connection between the mandrel and the constraining sleeve and permits the mandrel and seal stack to be inserted in the seal bore while the constraining sleeve moves upwardly relative to the mandrel.

Abstract: A firing mechanism for a downhole perforating gun comprises two cooperating housing sections having closed end walls in abutment. The lower housing section contains a booster charge and the primer cord for firing the gun. The upper housing section contains a detonatable primer, a hammer, and a downwardly directed explosive charge positioned between the primer and the bottom end wall of the upper housing. The upper housing is secured to the lower housing by a collet latch which, if firing of the gun does not occur, can be released by the exertion of a substantial upward force on a fishing neck provided in the assemblage of the upper housing. The defective elements can then be repaired or replaced, the upper housing reinserted in the well by wireline, and latched into an operative position with respect to the lower housing to permit another attempt to fire the perforating gun.

Abstract: A retrievable well packer and gravel packing system employing a multi-component packing element system is disclosed. The packing element system is expandable under axial compression to seal the annulus between a production or treatment tubing string and the well casing. The packing element system includes outer elastically deformable anti-extrusion backup rings and a central primary seal. A resilient member conformable to the surrounding countour, such as wire mesh, is employed between the central primary seal and each backup ring to allow retraction of the backup rings for retrieval.

Abstract: A redundant firing mechanism for a perforating gun utilized in subterranean wells comprises a hollow housing assembly incorporating two spaced primer charges disposed in vertically spaced relationship. A fluid pressure chamber is defined within the hollow housing assembly and is closed at the top end of the assembly by a frangible barrier disc. A fluid pressure actuated hammer is provided to impact upon the lowermost one of the primers in response to fluid pressure developed in the fluid pressure chamber. In the event that the lowermost primer does not detonate, a detonating bar may then be dropped through the tubing string to break the frangible barrier and impact upon a second hammer disposed in overlying relationship to the second primer.

Abstract: A packer apparatus for use in a subterranean well comprises an inner mandrel and means for applying tension to the inner mandrel to set radially expandable slips and packing elements. The mandrel can be releasably positioned in a first position to secure the slips and packing element in the retracted position and can be shifted to a second position in which engagable lock segments secure the slips and packing element in expanded configuration. The packer can be released by rotational manipulation or by axial force. The packer apparatus can be used with rotationally manipulatable well tools positioned either above or below the packer apparatus.

Abstract: A compressed fluid pressure actuated firing mechanism for a well perforating gun comprises a hollow housing assembly defining a mounting for a primer, a hammer releasably secured above the primer for movement towards the primer, and a fluid pressure chamber associated with the hammer for effecting a compressed fluid pressure force on the latching mechanism for the hammer and on the hammer to move it into impact engagement with the primer. The fluid pressure applied to the hammer is produced by permitting a selected fluid pressure surrounding the fluid pressure chamber to be forced into the fluid pressure chamber through at least one unidirectional check valve, thus compressing the fluid pressure within the fluid pressure chamber. The upper portions of the hammer are in contact with this compressed fluid pressure and the lower portions of the hammer are in contact with the selected fluid pressure.

Abstract: An anchoring apparatus for securing a production tubing string against axial movement in a subterranean well is disclosed. The anchoring apparatus can be employed with a conventional sucker rod pumping apparatus transporting fluids through the production tubing. A separate injection line is attached to the exterior of the production tubing and treating fluids are injected therethrough. A conduit which can be connected to the separate injection line extends along the exterior of the inner body of the anchoring apparatus in an axially extending groove and extends through encircling anchoring slips which are expanded by rotational movement of the production tubing and of the body of the anchoring apparatus.

Abstract: An injection tool for use in injecting fluids through perforations in the well bore of an oil or gas well is mechanically set and mechanically releasable. Fluid can be injected between upper and lower packing elements into a selected perforation. The upper and lower packing elements on opposite sides of the perforation into which fluid is injected are retractable, and any pressure differential across the upper packing elements or across the lower packing elements can be separately equalized.

Abstract: A subterranean well tool such as a packer and attached telescoping seal receptacle assembly is disclosed. The tool is fabricated from a plurality of threaded tubular members and annular deformable rings fabricated of a metal softer than the tubular members are used to establish metal-to-metal sealing integrity between interengagable component members. Upon full engagement, sealing integrity is established along the transverse interface between each tubular member and the deformed seal ring. During initial disengagement, sealing integrity is maintained along a bearing inclined interface between the ring and at least one tubular member adjacent the threaded connection.

Abstract: A more reliable operation of a multisection perforating gun for a subterranean well is achieved by disposing a detonation-transmitting element in parallel relationship to the conventional arrangement of booster charges and primer cords by which the detonating energy is transmitted from one gun section to the next. In one embodiment the detonation-transmitting element extends adjacent the primer cord from the upper portion of a gun section to a medial portion of the primer cord in the gun section, where the bottom end of the detonation-transmitting element is secured to an auxiliary booster charge having sufficient detonating energy to effect the detonation of the medial portion of the primer cord. In another modification, the detonation-transmitting element is radially spaced from the primer cord and has a circular, radially disposed portion at its upper end which is ignited by the booster charge secured to the bottom end of the flame-transmitting element in the upwardly adjacent section.

Abstract: A retrievable well tool for use in a subterranean well conduit utilizes plural valving elements to establish a fluid bypass around at least one annular elastomeric sealing element in response to movement of a control mandrel. The annular elastomeric sealing element actuates slips carried on the tool to engage the conduit wall in response to a differential pressure across the sealing element. The fluid bypass established by movement of the control mandrel is accomplished prior to an effective disengaging movement being imparted to the actuated slip elements.

Abstract: A locking apparatus for positioning a well tool within a subterranean well bore and comprising a primary locking member attached to the well tool; a nipple incorporable in a subterranean well conduit; and running and retrieving tools for positioning the lock member is disclosed. The lock has a no-go shoulder for initially positioning the lock adjacent the nipple and radially expandable locking dogs for carrying both upwardly and downwardly directed forces upon full expansion thereof after the no-go shoulder has been disengaged. At least two interlocking members disengageable only by separate manipulations maintain the locking dogs in a radially expanded fully engaged position. A retrieving tool having a rotational alignment means to position the tool relative to the lock is used to separately manipulate the interlocking members and to pull the disengaged lock from the well.

Abstract: A metal-to-metal fluid tight seal configuration formed between two abutting tubular members for use in subterranean oil and gas wells is disclosed. A metal-to-metal fluid tight seal is utilized in a shear release expansion joint assembly mounted by means of an anchor seal assembly in a conventional downhole packer. Sealing engagement is provided by plastic deformation of an annular seal ring between two abutting tubular members which are less ductile than the seal ring. In the preferred embodiment the metal-to-metal fluid tight seal is formed between abutting box and pin tubular members and the plastic deformation of the circular ring occurs as the ring is received within a groove in one of the abutting tubular members which has a dissimilar profile in comparison to the cross-section of the circular ring. Plastic deformation occurs as the box and pin members are rotationally threaded together and a continuous fluid tight seal is maintained along surfaces of both tubular members.

Abstract: A method and apparatus for permanently locking a shiftable valve member in a well conduit in an open position is provided by permitting a spring metal band to expand from a contracted, run-in position to a radially enlarged locking position holding the shiftable valve member in an open position. Positioning lugs are additionally provided which are operable by upward movement of a mandrel to determine whether an actuating sleeve for the shiftable valve member is properly located in its position corresponding to the closed position of the valve so that it will not interfere with the operation of the expanding lock open band member. The tool can be used with a flow tube actuated flapper valve or with other conventional valves.

Abstract: A valving apparatus for use in controlling the fluid pressure in a subterranean well conduit and in the annulus surrounding the conduit is disclosed. The valving apparatus is of the shuttle type and is shiftable between a closed position and an open position allowing flow within the tubing by the application of fluid pressure in the tubing above the valve. Pressure equalization below the valve is provided when the valve is in the closed position thus permitting the apparatus to be used with well tools in which annulus and tubing pressure must be equalized. A plug selectively inserted within the valve apparatus prevents the flow of fluids through the conduit in one direction and permits the build up of said fluid pressure. An annular fluid bypass does permit flow around the plug when the valve is shifted to the open position. An annular elastomeric sealing mass cooperates with a relatively movable annular ridge to provide sealing action for the valving apparatus.

Abstract: A method and apparatus for effecting the sealing of a well conduit comprises the positioning of a sealing plug unit within a special nipple provided in the well conduit and defining first and second surfaces and a seal bore. The sealing plug unit is provided with external seal elements cooperable with the seal bore and a first and second latching elements respectively cooperable with the first and second surfaces provided on the nipple. The sealing plug is actuated by first passing it downwardly through the nipple and then retracting it upwardly, whereupon the first of the latching elements engages with one of the surfaces on the nipple, thus preventing further upward movement on the assembly and permitting the application of a tensile force to release the plugging unit from the remainder of the unit to bring a camming sleeve into engagement with the second latching element to cam such element outwardly into engagement with an upper recess of the nipple.