Abstract: Methods and apparatus are provided for retrieving an inflatable packer of a type which may be passed through a small diameter tubing, seal against a relatively large diameter casing by passing fluid to the packer through a remedial tubing, and then be retrieved to the surface through the small diameter tubing. If the downhole equipment assembly becomes hung up during retrieval, fluid may be passed through the remedial tubing to release an upper portion of the packer actuator assembly from a lower portion of the packer actuator assembly. The released upper portion and remedial tubing may then be retrieved to the surface, and a conventional fishing tool utilized to subsequently retrieve the lower portion and the packer.

Abstract: A fluid pressure activated firing head for a perforating gun disposed in a subterranean well by a packer is provided with a column of clean fluid overlying and filling the bore of the firing head but communicating with the casing annulus above the set packer. An annular fluid passage extends from the top of the clean fluid column through the set packer and ending in an inverted U-shaped annular passage. A pressure transmitting seal is mounted in the downwardly extending leg of the annular fluid passage to permit the entire fluid passage to be filled with clean fluid of a lighter density than the casing annulus fluids, thus insuring that casing annulus fluid can never enter the interior of the pressure activated firing head.

Abstract: A sealing system for a valve disposed downhole in a subterranean well and subject to a high-temperature and high-pressure environment, comprises an annular valve seat defining a primary annular metallic seating surface surrounded by a groove within which is mounted a nonresilient, nonmetallic sealing element which is spring urged to project axially beyond the end of the primary sealing surface. The valve head is provided by a primary metallic sealing surface which, as the valve head moves toward engagement with the valve seat first engages the nonresilient, nonmetallic sealing element and deflects same axially and concurrently expands it radially outwardly so that the nonmetallic, nonresilient sealing element ends up engaging a cylindrical surface surrounding the primary sealing surface formed on the valve head.

Abstract: A non-destructive on-site method of inspection, and testing of the insulating performance and reconditioning of a concentric insulating tubular conduit member is disclosed. The insulating tubular conduit members comprise concentric walled members with an intermediate annular insulating cavity defined therebetween. This non-destructive method of testing and inspection is based on a determination of the presence of an unacceptable level of moisture in the annular insulating cavity. Visual, auditory, electrical, and radioactive indicating means can be employed in accordance with the principles of this invention.

Abstract: A fluid pressure activated firing head for a perforating gun disposed in a subterranean well by a packer is provided with a column of clean fluid overlying and filling the bore of the firing head but communicating with the casing annulus above the set packer. A fluid passage is provided at the top of the conduit extending the clean fluid column through the packer, and the downwardly facing leg of the annular fluid passage is provided with a pressure transmitting seal to permit the entire fluid passage to be filled with clean fluid of a lighter density than the casing annulus fluids, thus insuring that casing annulus fluid can never enter the interior of the pressure activated firing head.

Abstract: A sealing apparatus having particular utility in a submersible electric motor utilized in subterranean wells comprises a tubular housing assembly securable in upwardly projecting, sealed relationship to the motor housing. An extension of the motor shaft projects upwardly through the tubular housing to drive a pump or other subterranean well tool. The upper end of the extension shaft is exposed to well fluids and a first shaft seal is mounted in a seal mounting chamber defined in the upper end of the tubular housing assemblage. Below the seal mounting chamber, the tubular housing assemblage defines a diaphragm chamber. A conduit is provided between the lower portions of the seal mounting chamber and the lower portions of the diaphragm chamber.

Abstract: A seal bore packer comprising a packer subassembly which can be employed with either wireline or tubing manipulatable packer setting subassemblies is disclosed. Packing elements and slips on a packer subassembly are expanded when relative axial forces are applied to the packer by wireline or mechanical setting forces. The packer has an inner mandrel and intermediate mandrel connected by a shear pin. A collapsible ring holds the outer packer assembly, including slips and packing elements, normally secured to the intermediate mandrel. Relative movement between the intermediate mandrel and the inner mandrel releases the packer.

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 removable bushing for slidably and sealably supporting a mandrel within the bore of a well conduit comprises an outer tubular body insertable in the well conduit in series relation. Said outer tubular body defines an internal seal bore and an annular latching recess adjacent the seal bore. An internal tubular body assembly is telescopically inserted in the well conduit and carries external seals engagable with the seal bore and an internal seal stack. The internal tubular body further comprises a collet having a plurality of peripherally spaced locking arms terminating in locking heads which are engagable with the annular recess in the outer tubular body. A mandrel is inserted within the bore of the outer tubular body in sealing engagement with the internal seal stack.

Abstract: A pre-cured proppant charge useful, for example, for propping a fracture in a subterranean formation is disclosed. The charge is made up of a large number of particles composed of a single substrate particle which can be silica sand, glass beads, or the like, coated with a thermoset resin. The thermoset resin is one which, when it is the resin coating on particles of a proppant charge, produces such a charge when the Conductivity Ratio, as defined herein, throughout a given closure stress range is greater than that of a charge of the uncoated particles. The proppant is produced by coating the particulate substrate with a suitable thermosettable resin, controlling the coating step to produce substrate particles coated with a fusible, thermosetting resin, and curing the resin by heating the coated particles, so that substantially all of the resin coated particles are composed of a single substrate particle with a thermoset resin coating thereon, prior to introduction into a subterranean well.

Abstract: A downhole injection valve for selectively opening and closing the bore of a tubing string to permit the passage of chemical treatment fluid at a preselected flow rate to a downhole tool comprises a first annular valve element mounted in a valve housing which is connected in a tubing string above the downhole tool. A slip joint is connected between the valve housing and the downhole tool to permit relative upward and downward movement of the valve housing with respect to the tool. A second annular valve element is disposed in surrounding relationship to a support rod which is inserted in the tubing string and supported at its bottom end by the downhole tool. Upward movement of the tubing string effects contact of the first and second annular valve elements to close all fluid flow through the bore of the tubing string. Conversely, downward movement of the tubing string will effect axial separation of the valve elements to permit fluid flow through the tubing string to the downhole tool.

Abstract: A high energy firing mechanism for a well perforating gun comprises a downwardly directed shaped charge which is discharged by an impact detonatable primer. The explosive jet developed by the downwardly directed shaped charge impinges upon a booster charge which in turn is connected to a primer cord leading to the shaped charges of a perforating gun. Sufficient detonating energy is produced to assure high energy detonation of the booster charge and primer cord, even though such elements may be formed from a thermal resistant explosive.

Abstract: A method and apparatus for effecting the firing of a perforating gun having a plurality of vertically spaced, shaped charges wherein the firing is accomplished from the lowermost shaped charge to the uppermost shaped charge. In one modification, the detonation of the shaped charges is accomplished by a primer cord extending through all the gun sections, which is detonated only by a booster charge located in the bottom portion of the perforating gun housing. The booster charge is in fluid communication with the interior of the housing and, upon the occurrence of leakage of well fluids into the housing, the booster charge is rendered ineffective, thus preventing the firing of the perforating gun when the lower portion of the gun is filled with well fluids. In another modification, a conventional primer cord with booster charges on each end is inserted in each gun section, as is a length of flame-transmitting tubing.

Abstract: An actuating assembly for a single set production-injection packer and a method of operation are provided for use in variable temperature downhole environments, such as are encountered in steam injection processes for petroleum recovery operations. After the packer is set, a compensator allows for fluid volume increase or decrease of the packer fluid chamber to maintain the proper packer inflation pressure. A piston-type accumulator with a preselected nitrogen load prevents rupture of the packer by compressing the nitrogen load while further expanding the fluid chamber for the packer fluid should the inflation pressure rise above a selected level. The packer may be unset by axially raising the tubing with respect to the set packer to open the packer fluid to downhole pressure.

Abstract: Apparatus for injecting high-temperature steam at a selected mass flow rate into a plurality of vertically spaced production formations of a subterranean well comprises a plurality of choke devices connected in series relationship in a tubing string extending to the well surface. Each choke device is positioned immediately above or adjacent to a production formation and defines a flow diversion device which extracts a predetermined portion of steam flow from the main steam flow, moving downwardly through the tubing string and directs such diverted steam portion into the inlet chamber of a Venturi passage. The steam is accelerated by the Venturi passage to its critical mass flow rate and is discharged into the production formation. In a preferred embodiment of the invention, the Venturi passage is connected in series with a fluid mixing apparatus which effects an intimate mixture of vapor and water components of the steam.

Abstract: A downhole injection valve for selectively opening and closing the bore of a tubing string to permit the passage of chemical treatment fluid to a downhole tool comprises a first annular valve element mounted in a valve housing which is connected in a tubing string above the downhole tool. A slip joint is connected between the valve housing and the downhole tool to permit relative upward and downward movement of the valve housing with respect to the tool. A second annular valve element is disposed in surrounding relationship to a support rod which is inserted in the tubing string and supported at its bottom end by the downhole tool. Upward movement of the tubing string will then effect contact of the first annular valve element carried by the valve housing with the second annular valve element carried by the support rod, and thus move such elements into engagement and close all fluid flow through the bore of the tubing string.

Abstract: A conduit centralizer comprises segmented, sliding upper and lower collars connected by a plurality of axially extending, outwardly bowed leaf springs. Each collar is formed by the hinged connection on a plurality of segments in close fitting contact with the outer diameter of a pipe. The ends of the leaf springs are respectively inserted within the individual segments and welded to the segments. Individual collar segment sections or subassemblies comprising upper and lower collar segments secured to a single intermediate bowed leaf spring can then be interconnected to form a concentric centralizer.

Abstract: A valve having a rotary valve head with an elastomeric seal attached to the valve head for use in a conduit is disclosed. Separate embodiments for use in a downhole tool and in an accessible surface valve are disclosed. An axially movable actuator tube is engagable with the elastomeric seal to maintain sealing integrity. A valve head with an integrally mounted seal can be actuated by an axially movable camming member or by a lever pivoting about an axis transverse to the conduit. Rotation of the valve head from the closed position aligns a flow passage with the conduit to permit fluid flow.

Abstract: An apparatus for effecting the firing of a multisection perforating gun having a plurality of vertically spaced shaped charges wherein the firing is accomplished from the lowermost shaped charge to the uppermost shaped charge. The detonation of the shaped charges is accomplished by a primer cord which is detonated only by a booster charge located in the bottom portion of the assembled perforating gun housing. Hollow nipples are utilized to effect the assembly of the plurality of tubular gun sections in axially stacked relationship and a fusible tubular guide element is provided between each adjacent pair of nipples so as to permit a continuous primer cord, as well as a fusible cord, to be concurrently inserted throughout the length of the gun.

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.