Abstract: Mechanism for achieving the radial expansion of an annular elastomeric pack-off unit between the bore of a casing and the exterior of a liner, comprises a tubular sealing assembly threadably connected between the liner and the hanger and defining two inwardly projecting annular seals, an annular fluid pressure chamber, and radially disposed fluid inlet ports for the fluid pressure chamber located between the two inwardly projecting annular seals. An annular piston mounted in the annular pressure chamber effects the compressible expansion of an annular elastomeric seal element. A tubing extension of the work string is provided which may be selectively moved into sealing relationship with either or both of the internally projecting annular seals. During the cementing operation, the tubing extension engages both annular seals.

Abstract: The subterranean well safety valve useful in oil and gas wells employs a rotatable flapper to close a fluid production flow path. A through-the-flapper equalizing valve means is employed to equalize pressure across the closed valve in response to movement of an axially shiftable flow tube actuator. A spring-loaded poppet valve extends through the flapper on the periphery of the flapper in alignment with the end of the flow tube. The equalizing valve is opened upon initial movement of the flow tube followed by full opening of the flapper.

Abstract: A lubricator valve assembly comprises a reciprocably rotatable ball valve which is operated between open and closed positions solely through the selective application of control pressures and/or tubing pressure above the valve to a double acting sleeve type actuating piston. One end of the actuating piston has a valving piston formed thereon which cooperates with a seal bore in the housing to effect the opening or closing of a bypass fluid passage extending from a region below the ball valve to a region above the ball valve. Such valving piston also functions as part of a lost motion connection between the actuating sleeve piston and a reciprocable actuator for rotating the ball valve. In opening the ball valve, the valving piston first moves upwardly to establish a fluid bypass around the closed ball valve and then establishes contact with the actuator to rotate the ball valve to an open position.

Abstract: The disclosure provides an actuating mechanism for a rotatable ball valve unit wherein several axially extending pistons and cylinder units or bellows elements are mounted in the wall of the outer housing of the ball valve in angularly spaced relationship. Two diametrically opposed piston or bellows elements actuate the mechanism for axially shifting and then rotating the ball valve, while the remaining piston or bellows elements effect a displacement of the flow tube to maintain a seal carried by the flow tube in sealing engagement with the ball after its rotational movement has been accomplished. The desired delay of movement of the flow tube is accomplished through either varying the size of the bellows element or the spring constants of the springs opposing the actuating movement of the pistons, bellows elements or a combination of these.

Abstract: An assembly for use in establishing sealing integrity between an inner and outer conduit in a subterranean well is disclosed. A multi-component seal assembly having a plurality of individual seal units is assembled on the exterior of an inner tubular conduit for insertion into the bore of an inplace tubular seal receptacle located in a subterranean well. The tubular conduit and associated seal assembly can be inserted into the bore and axial reciprocation of the tubular conduit relative to the seal receptacle is possible without damage to vee-shaped primary elastomeric sealing elements during insertion, while sealing integrity is maintained within the seal receptacle and during unloading and removal of the seals from the seal receptacle.

Abstract: A valve for use in controlling flow in a subterranean well and using an expandable and contractable fluid sealing bellows is disclosed. The valve has a valve closure member such as a ball valve head acutated by an increase in control fluid pressure. Control pressure causes the bellows to expand or contract and a control rod engaging the bellows can be shifted. The control rod is part of an actuating mechanism for shifting the valve closure member between open and closed positions. The bellows can support the difference between control pressure and well pressure which are respectively present on the exterior and interior of each bellows element.

Abstract: A subsurface safety valve for use in subterranean oil and gas well which is actuated by pressure fluctuations in the tubing-casing annulus is disclosed. The safety valve assembly consists of a safety valve mounted in a packer which is actuated by a subsurface control located above the packer. Annulus pressure variations are controlled by a surface unit. The subsurface control utilizes a reference pressure chamber in which the pressure is initially adjustable to compensate for hydrostatic pressure in the annulus. Leakage of the gas in a dome pressure chamber in the subsurface control is impeded by the presence of a barrier fluid impervious to the passage of gas therethrough, with the barrier fluid being maintained at a higher pressure than the reference pressure in the dome charged chamber.

Abstract: A method and apparatus for installing in a well conduit by a single trip on an auxiliary conduit a combination well condition sensing device and flow cut off valving elements. The cooperating valving elements are of annular configuration and the auxiliary conduit passes through the bore of the valving elements and is mechanically connected to one of the valving elements. The entire apparatus may be run into the well conduit in a single trip on the auxiliary conduit and actuated to a flow shut off position by longitudinal manipulation of the apparatus. Pressurization of the upper well conduit and secondary manipulation of the apparatus and the auxiliary conduit permits the return of the valving elements to an open flow position.

Abstract: An equalizing annulus valve for use in controlling flow in the annulus between two tubular conduits in a subterranean oil or gas well has a control pressure responsive main valve piston and a booster piston for closing radial flow ports. The booster piston is spring loaded relative to the main piston and excess annulus pressure below the valve acts on the booster piston rather than on the main piston. The main piston can be partially opened before abutting the booster piston to permit pressure below the valve to meter through an equalizing port in the main piston and through the main flow ports. When the pressure is equalized, the main piston and booster piston can be shifted to a fully open position. An auxiliary piston responsive to an increase in annulus pressure can also be used to shift the main piston.

Abstract: A retrievable well tool for use in a subterranean well utilizes plural valving elements to establish a fluid by-pass around an annular elastomeric sealing element in response to either downward or upward movement of a control mandrel. The fluid by-pass established by movement of the control mandrel is accomplished prior to any effective disengaging movement being imparted to the cooperating cone and slip elements.

Abstract: The disclosure relates to an improved flapper type saftey valve and valve housing for use in subterranean wells wherein the flapper valve is actuated from a horizontal closed position to a vertical open position by contact with a downwardly moving actuating sleeve. The top surface of the valve is elevated so that the bottom edge of the actuating sleeve always contacts the flapper valve at a position spaced from the axis of the pivot mounting, thereby assuring that the opening force applied to the flapper valve has a maximum moment arm in order to overcome any fluid pressure differential existing across the flapper valve. The valve is mounted in an eccentic bore on an eccentric mounting base and fully opened flapper valve provides maximum flow area through the valve.

Abstract: The disclosure provides a method and apparatus for effecting the noncontact opening of a flapper valve disposed downhole in a well. Such flapper valves may be located below a seal bore in a downhole tool such as a packer. An annular housing having external seals engagable with the seal bore can be positioned within the downhole tool. Fluid circulation through the annular housing during insertion is permitted by a ball valve mounted in its axial bore and engagable with a downwardly facing sealing surface. Upon engagement of the seals on the annular housing with the seal bore, the housing is converted into a piston and the amount of force exerted on trapped fluid between the annular housing and the flapper valve may be adjusted by adding weight from the tubing string. Fluid pressure above the flapper valve is increased to a level exceeding the closing forces on the flapper valve and the valve opens without any mechanical contact being made therewith.

Abstract: This invention provides a method and apparatus for effecting two stage cementing of well conduits by supplying cement through a tubular member. The apparatus involved provides a tubular conduit extension attachable to the bottom end of a well conduit and defines a cementing passage through its bottom end. Cementing ports are provided in the extension at a distance above its bottom end. A pair of concentrically adjacent valve units are communicable with the extension with the inner valve unit positioned in a closed position relative to the cement ports. The inner valve unit defines a seal bore which receives a mandrel which is secured to the tubular member. The mandrel incorporates two pilot sleeve valves which are positioned in closing relationship to radial passages in the hollow mandrel and each of which defines an upwardly facing surface for reception of sealing balls or plugs.

Abstract: A ball type safety valve mounted in a movable cage for automatically closing a subterranean well conduit is disclosed. The ball has a central flow passage which can be aligned with the tubing to permit production and can be automatically rotated to block the tubing. The ball is moved from its closed to its open position by an increase in control fluid pressure, preferably in an external control fluid line extending to the surface of the well. An increase in control fluid pressure causes the cage to move axially and rotation is imparted by the offset camming means attached to a stationary base member. The base member is adjustable relative to the valve housing and to the cage to insure that the valve is fully open and fully closed at opposite extremes of the travel of the cage and ball assembly.

Abstract: A cementing float valve for subterranean wells is provided wherein a wiping plug retaining sleeve is concentrically positioned on the top of a float valve and secured to an outer housing by cementitous or other drillable material. the retaining sleeve provides a downwardly facing latching surface and a seal bore disposed above the latching surface for cooperation respectively with an expandable ring and an annular seal conventionally provided on a wiping plug.

Abstract: A method is provided for propping a fracture in a subterranean formation which comprises injecting into a subterranean well a suspension in a carrier fluid of a pre-cured proppant charge, the pre-cured proppant charge being pre-cured prior to injection into the well, and comprising prior to injection into the well, resin coated sand particles most of which are composed of a single substrate particle with a thermoset resite coating thereon, the resite coating being one which, when it is the resin coating on sand particles of a proppant charge, produces a charge wherein at least one of: (a) the Conductivity Ratio thereof, throughout a given closure stress range, is greater than that of a charge of the uncoated sand particles having substantially the same particle size distribution; or (b) the Permeability Ratio thereof, throughout the stress range of about 2,000 to about 10,000 p.s.i.

Abstract: The disclosure provides a method and apparatus for effecting the locking of a well tool in any selected one of a plurality of identical nipples provided in spaced relationship along a well tubing string. Each nipple is provided with an annular recess to receive expandable locking dogs carried by the locking mechanism and an upwardly facing no-go shoulder which is of no lesser diameter than the bore of the tubular string. The locking mechanism is shearably mounted on a running tool and incorporates an expansible C-ring which has a downwardly facing shoulder engagable, when expanded, with the no-go shoulder of the selected locking nipple. The expansible C-ring is held in a retracted position by a collet having spring arms which pass freely downwardly through any or all of the nipples but, when moved upwardly through a selected nipple, engage a surface on the nipple and pull the collet out of its retaining position with respect to the expansible C-ring.

Abstract: An apparatus for effecting two stage cementing of well conduits by supplying cement through a smaller diameter tubular member. The apparatus involved provides a tubular assembly attachable to the bottom end of a well conduit. The tubular assembly defines an axial cementing passage through its bottom end. Cementing ports are provided in the tubular assembly above its bottom end to implement the second stage cementing operation. A tubular member is sealingly secured in the upper end of the tubular assembly and valve units are provided between the end of the tubular member and the cementing ports. The lower annular valve unit is selectively releasably positioned in a closed position relative to the radial cement ports. At the conclusion of the first stage of cementing, a first sealing plug is dropped through the tubular member into sealing engagement with the bore of the lower annular valve unit and fluid is applied through the tubular member to shift the lower annular valve unit to an open position.

Abstract: A packer adapted for thermal applications to provide sealing integrity between the tubing and casing in a subterranean well is disclosed in combination with a tubing anchor seal assembly for providing secured sealing integrity between the tubing and the seal bore of the packer. The tubing anchor seal assembly comprises an inner mandrel attached to the tubing string. Annular seals are disposed on the exterior of the mandrel. A latch prevents upward movement of the tubing anchor seal assembly relative to the packer, while downward movement is prevented by abutting shoulders. A concentric sleeve engages the seals and radial protrusions on the mandrel transmit longitudinal force to the seals trapped against the sleeve to energize the seals which need not be elastomeric.

Abstract: The invention relates to an annular seal system designed for high pressure applications in subterranean wells. The annular seal system comprises a vertical stack of subassemblies. Each subassembly incorporates an annular sealing element formed from an elastomeric material, such as a perfluoroelastomer, which is provided with a truncated pear-shaped cross-sectional configuration having reversely curved axial side surfaces. The sealing element is abutted on each axial side by a uniform thickness annular bearing element formed from a thermoplastic such as a polyphenylene sulfide resin having good bearing properties. Each of the thermoplastic bearing elements is in turn abutted by an annular metallic restraining element having correspondingly shaped reversely curved axial side surfaces and defining an inverted truncated pear-shaped cross-sectional configuration.