Abstract: A slip retention mechanism for a packer or hanger for a subterranean well comprises a slip retention sleeve disposed in surrounding relationship to a tubular body on which cone elements are mounted for axial movement. Segment-shaped slips are mounted in the space intermediate the retention sleeve and the tubular body and have inner surfaces cooperable with the cone elements to effect a radially outward displacement of the slip elements upon relative axial movement of the cone elements. The slip retention sleeve is provided with a plurality of peripherally spaced windows separated by axially extending bars. Each slip segment is provided with an axially extending slot in its outer surface which is aligned with one of the window bars. A leaf spring is mounted intermediate the window bar and the axial slot to exert a radially inwardly directed force on the respective slip segment to hold it in a retracted position.

Abstract: A separable fluid pressure activated firing mehanism for a perforating gun comprises a pressure-operated tubing valve, a packer, and a tubular housing assembly defining a plurality of fluid pressure chambers therein. The first chamber contains a light density, clean, compressible fluid which is subject to well annulus pressure above the packer to provide a reference pressure. A second chamber sealably mounts a piston-type firing pin, which is normally secured by a locked latch in an elevated position above a detonatable primer and the lower portion of said firing pin is exposed to the reference pressure. The latch is unlocked through the application of a predetermined annulus pressure above the packer to a locking piston which moves to unlock the latch and trap the reference pressure in the first chamber. A further increase in said annulus pressure opens the tubing valve.

Abstract: This invention relates to a method for achieving a seal by an expandable packing element having a generally tubular configuration and being fabricated from elastomeric material adapted to be utilized in conjunction with a packer apparatus within a well bore conduit during the completion or workover of a subterranean oil or gas well. Preferably the packing element is formed from a resilient elastomeric material such as ethylene propylene diene monomer adapted to withstand elevated temperatures and high pressures in subterranean wells. The tubular body member has an imperforate protective coating at least over its exterior surfaces, the coating being resistant to exposure to steam and hydrocarbons at elevated temperatures for extended periods for protection of the body member prior to its controlled expansion into well sealing relation, said coating becoming imperforate by said expansion.

Abstract: Apparatus for testing a selected zone of a subterranean bore, which may comprise a subterranean uncased well bore, comprises a pair of inflatable packers mounted in spaced relationship on a tubular outer housing to define the axial extent of the selected zone to be tested. Fluid pressure passages for inflating the packers, for monitoring the fluid pressure between the inflated packers, and above and below the inflated packers, are defined by a plurality of peripherally spaced passages formed in a multi-section tubular conduit. The fluid passages in each conduit section do not extend axially beyond the ends of the particular section but communicate with peripherally spaced radial ports.

Abstract: A plurality of packing elements are mounted in vertically spaced relationship on a tubing string with the spacing of the elements corresponding generally to the spacing of a plurality of sets of perforations in a well conduit. The lowermost packing unit is provided with radially expanding locking elements which engage a locking groove provided in the well conduit. All packing units incorporate expandable elastomeric sealing members and are set by the application of tension to the tubing string and are unset by the subsequent application of a higher degree of tension to the tubing string.

Abstract: A separable fluid pressure activated firing mechanism for a perforating gun comprises a pressure-operated tubing valve, a packer, and a tubular housing assembly defining a plurality of fluid pressure chambers therein. The first chamber contains a light density, clean, compressible fluid which is subject to well annulus pressure above the packer to provide a reference pressure. A second chamber sealably mounts a piston-type firing pin, which is normally secured by a locked latch in an elevated position above a detonatable primer and the lower portion of said firing pin is exposed to the reference pressure. The latch is unlocked through the application of a predetermined annulus pressure above the packer to a locking piston which moves to unlock the latch and trap the reference pressure in the first chamber. A further increase in said annulus pressure opens the tubing valve.

Abstract: In a safety valve having an axially shiftable actuating sleeve operable to move a valve head from a closed to an open position, the actuating movement of the actuating sleeve is normally produced by a small diameter piston mounted on an axially extending spindle secured to the valve housing and cooperating with a primary cylinder which is abuttingly secured to the actuating sleeve. A secondary spindle and cooperating cylinder are provided which are supplied with fluid pressure by an entirely separate line extending to the well surface. The second cylinder has only abutting contact with the actuating sleeve and may be utilized to effect the movement of the actuating sleeve in the event of the failure of the primary cylinder. In a modification, a fixed cylinder housing defines a pair of secondary cylinder bores in which secondary rod pistons are slidably mounted to effect the movement of the actuating sleeve.

Abstract: A plurality of packing elements are mounted in vertically spaced relationship on a tubing string with the spacing of the elements corresponding generally to the spacing of a plurality of sets of perforations in a well conduit. The lowermost packing unit is provided with radially expanding locking elements which engage a locking groove provided in the wall conduit. All packing units incorporate expandable elastomeric sealing members and are set by the application of tension to the tubing string and are unset by the subsequent application of a higher degree of tension to the tubing string.

Abstract: The invention provides an apparatus for limiting tension produced in a tubular string extending from a packer set in a subterranean well to the well surface. Such apparatus comprises a receptacle secured to the packer and defining an elongated seal bore, and a mandrel telescopically and sealably related to the seal bore, the mandrel being connected to the bottom end of the tubing string. In one embodiment, a collet, incorporated in the receptacle for cooperating with an abutment formed on the mandrel, thereby securing the mandrel and the receptacle in a telescopically contracted position until sufficient tensile force is exerted on the mandrel to cause the collet arms to be expanded by the abutment to permit upward movement of the mandrel relative to the receptacle.

Abstract: A packer, preferably utilized for dual string operations, comprising a plurality of axially stacked body elements including, from the bottom up, a hydraulic housing, a lower cone element, an annular slip cage containing radially expansible slip elements, an upper cone element, a lower packing expander, an expandable packing element, an upper packing expander, a receptacle, and a retainer plate. All of said elements are provided with two bores equal in diameter to that of the tubing string to be run which extend entirely through the axial stack. One bore accomodates a long string mandrel and the other bore accomodates a short string mandrel conventionally connected to a short tubing string. The short string mandrel is connected at one end to the hydraulic housing and at the other end to the receptacle housing. Fluid pressure is applied to concurrently effect the downward movement of the hydraulic housing and the upward movement of the lower cone to set the packer into engagement with the conduit wall.

Abstract: A method is provided for removing paraffin deposits from the interior of a hydrocarbon transmission conduit, such as a subsea pipeline. The method comprises the steps of introducing into an isolated length of the conduit containing the paraffin a pre-determinable amount of an emulsified mixture of an aqueous solution and a hydrocarbon solution. The composition used in the method incorporates an aqueous solution which comprises in-situ nitrogen-generating components together with a sufficient amount of a buffered pH adjuster to produce a buffered pH value for the aqueous solution to abate the time of the reaction rate of the nitrogen-generating components to a level permitting introduction of the components into the isolated length prior to completion of any significant portion of the reactin required to effect temperature melting of the paraffin deposits. In a preferred form, a crystalline modifier may be incorporated into the hydrocarbon solution.

Abstract: A method and apparatus for effecting the assembly and arming a multisection perforating gun for a subterranean well. Each of the gun sections has a plurality of vertically and angularly spaced shaped charge containers disposed with the primer ends located in concentric fashion about the vertical axis of the gun, thus defining an axial passage communicating with the bores of hollow nipples which respectively effect securement of one gun section to the next adjacent gun section. In one modification, a continuous primer cord is stored on a reel below the lowermost gun section and is then pulled successively upwardly through each of the additional gun sections as they are assembled. In another modification, each of the gun sections is provided with a length of fusible guide tubing interposed between the inner primer ends of all of such shaped charges and the continuous length of primer cord is fed downwardly through the axial passage defined by such guide tubing.

Abstract: A dynamic seal for effecting the sealing of a piston which is axially movable in a cylinder bore comprising a primary sealing element formed of a non-elastomeric sealing material having a hub portion secured to the piston element and an outwardly flaring skirt portion sealingly engagable with the cylinder bore. A secondary sealing element formed of a resilient metal has its central body portions secured to the piston element and defines a frustro-conical lip portion snugly engaging the exterior of the skirt portion of the primary seal element. Fluid pressure applied to the primary seal element causes it to expand the secondary seal element into a metal-to-metal sealing engagement with the bore of the cylinder.

Abstract: A plurality of packing elements are mounted in vertically spaced relationship on a tubing string with the spacing of the elements corresponding generally to the spacing of a plurality of sets of perforations in a well conduit. The lowermost packing unit is provided with radially expanding locking elements which engage a locking groove provided in the well conduit. All packing units incorporate expandable elastomeric sealing members and are set by the application of tension to the tubing string and are unset by the subsequent application of a higher degree of tension to the tubing string.

Abstract: A subsea test assembly securable in a subsea blowout preventer stack is used in methods for performing wellbore tests and for disconnecting a tubular string from a subsea wellhead. The test valve assembly includes an upper subassembly releasably latched to a lower subassembly. Dog members are latched and unlatched in a corkscrew manner requiring only a slight rotation, and are held in the locked position by an axially movable sleeve. Nominal rotation of the latch within the upper subassembly is required to latch and unlatch the dogs, and a relatively short stroke of the movable sleeve locks and unlocks the dog members. The latch may be hydraulically or mechanically deactivated. The valving of the test assembly preferably comprises a ball member having both a metallic and elastomeric seal for sealing the passageway through the assembly. The elastomeric seal is carried by the ball and engages a metallic sleeve axially movable below the ball for sealing engagement against the ball.

Abstract: A packer for effecting steam treatment of a production formation of a subterranean well comprises an insulated mandrel which is slidably inserted within the bore of an inner tubular body assembly. An outer operative tubular assembly surrounds the inner assembly and mounts a plurality of drag blocks, upper and lower cone elements, a plurality of radially displaceable slips cooperating with the upper and lower cone elements, and an outer packing element fabricated by an assemblage of high temperature resistant, non-resilient seal elements formed primarily of graphite. An inner packing element is provided in the inner tubular body assembly utilizing additional high temperature resistant, non-resilient seal elements formed primarily of graphite, which sealingly engages the insulated mandrel.

Abstract: A sealing assembly for effecting the sealing of an annulus between two telescopically related tubular conduits, of the type employed in subterranean wells, is achieved by utilizing annular seal backup elements dieformed from a knitted wire mesh by two successive dieforming steps. In the first dieforming, the knitted mesh backup element is formed to an external diameter equal to or preferably exceeding the maximum diameter that will be required for the backup member to assume when expanded into engagement with the outer wall of the annulus to be sealed. The second dieforming operation reduces the external diameter of the annular knitted mesh seal backup element to a dimension less than the outer wall of the annulus to be sealed, thus permitting convenient assembly and run-in of the sealing assemblage. The two step dieforming operation significantly reduces the amount of axial compressive force required to expand the sealing elements and the seal backup members to their sealed position.

Abstract: An injection tool for use in injecting fluids into perforations of a production formation of an oil or gas well is mechanically set in the bore of the casing traversing the production formation, and mechanically releasable therefrom so that chemical treatment fluid can be injected between upper and lower packing elements into a single or a selected vertical group of perforations. The injection tool is connected to the tubing string by a circulation valve operable by rotational movement of the tubing string. Injection of the chemical fluid treatment is accomplished with the circulation valve in the closed position, while the circulation valve is opened to equalize tubing and annulus pressure whenever required.

Abstract: An apparatus for extracting a virgin fluid sample from a selected formation of subterranean well comprises an outer tubular housing disposed between two packing elements straddling the selected formation and having radial ports communicating with the annulus adjacent the selected formation. A hollow mandrel extends entirely through the length of the tubular housing, and the lower portions of such mandrel cooperate with the bore of the internal tubular housing to define a sample-collecting chamber. Fluid passage from the radial ports to the collecting chamber are blocked in the run-in position of the apparatus by an axially shiftable valve sleeve, which is shear pinned in a flow-blocking position during run-in of the tool. Fluid pressure is then applied to the bore of the hollow mandrel to shift the valve sleeve upwardly and remove the valve sleeve from its flow-blocking position, thereby permitting flow from the radial ports into the sampling chamber.

Abstract: A packer for effecting steam treatment of a production formation of a subterranean well comprises an insulated mandrel which is slidably inserted within the bore of an inner tubular body assembly. An outer operative tubular assembly surrounds the inner assembly and mounts a plurality of drag blocks, upper and lower cone elements, a plurality of radially displaceable slips cooperating with the upper and lower cone elements, and an outer packing element fabricated by an assemblage of high temperature resistant, non-resilient seal elements formed primarily of graphite. An inner packing element is provided in the inner tubular body assembly, utilizing additional high temperature resistant, non-resilient seal elements formed primarily of graphite, which sealingly engages the insulated mandrel.