Mcevoy Oilfield Equipment Co.

Smith International, Inc.

Exxon Production Research Company

Stewart & Stevenson Oiltools, Inc.

David P Herd

John H Fowler

John W McCaskill

Thomas W Childers

Jack Whiteman

Robert D Barnett

Terry W Pollard

Duane E Gibson

A split gate for a gate valve regulating fluid flow with reduced gate drag. The split gate comprises a plurality of members for sealing a flowway intersecting a valve chamber. A first member seats against a first portion of the flowway and has a pressure-balancing surface pressure-isolated from the first flowway portion and from the valve chamber. A second member seats against a second portion of the flowway and allows pressure in the second flowway portion to bear on the pressure-balancing surface of the first member. Pressure in the valve chamber exceeding pressures in the flowway portions creates pressure differentials pressing the gate members more firmly against their seats, thereby increasing the frictional resistance opposing reciprocation of a closed gate to its open position. The invention provides that, to the extent of the area of the pressure-balancing surface, the net pressure differential seating the first member is the first flowway portion-to-second flowway portion pressure differential, in place of the higher pressure differential between the valve chamber and the first flowway portion. A similar result is obtained for the second member by reducing the areas for pressure differential to act on the second member. The invention thus reduces the effects of internal valve pressure differentials to lower the frictional gate drag resisting opening of the gate.

Pressure-balanced gate for split-gate valve

Combined metal-to-metal/compliant material stem sealing means for high pressure, balanced, rising stem gate valve includes at least one seal set at each of the actuator and balance stems. Each seal set comprises a pair of frustoconical metal ring gaskets between which are disposed two make-up rings of compliant, tough material of high lubricity, e.g. tetrafluoroethylene polymer. One make-up ring is adjacent to one gasket, and the other make-up ring is adjacent to the other gasket. A core ring of material that expands substantially less volumetrically upon heating than the make-up rings, e.g. compacted graphite, is disposed between the make-up rings. Around the inner periphery of the core ring adjacent the respective actuator or balance stem is disposed a bearing ring of material like that used for the make-up rings, e.g. tetrafluoroethylene polymer. The seal set is compressed by a packing retainer such that the metal gaskets are coined into metal-to-metal sealing engagement with the stems and adjacent valve body parts. The sandwich stack, consisting of the core ring and bearing ring disposed between the make-up rings, is deformed to conform to the shape of, and fills substantially all of the space between, the compressed metal ring gaskets. The volume of the core ring is approximately one-third of the total volume of the sandwich stack.

Seal

A high pressure gate valve having at least one pressure actuated seal means between the bonnet part of the valve body and the valve actuating stem and between the chamber part of the valve body and the valve actuating stem is disclosed. Each seal means includes at least one seal assembly. Each seal assembly includes two sets of plural, e.g., four, metal rings with an elevated temperature resistant and chemical resistant ring of solid lubricant, e.g., tetrafluoroethylene or graphite, separating the metal rings. Each metal ring is softer than the stem and is of rectangular cross-section. The seal assembly is actuated by pressure on larger follower metal rings. When multiple seal means are involved, another metal follower ring larger than the set of metal rings of the seal means also separates the two sets of seal assemblies. The seal means may also include a biasing spring. Each seal means is disposed in an annular pocket or stuffing box in the adjacent part of the valve body extending around the stem. Each stuffing box is closed by an annular packing gland screwed into the stuffing box far enough to flatten out the lubricant sufficiently for the inner and outer peripheries of the inner and outer metal rings respectively of the set of metal rings to engage the stem and stuffing box walls respectively and seal in the lubricant ring. The valve stem sealing arrangement may also be employed for packing off lock screws and in other situations wherein relatively movable parts are to be sealed both during and after relative motion.

High pressure gate valve with preloaded, stacked, solid lubricated stem

A fail-safe non-pressure locking valve, actuated by hydraulic controls responsive to ambient sea pressure, disposed over 1000 feet below the surface on a submerged pipeline controlling the flow of fluids therethrough. The valve includes a housing having a chamber within which a gate, having upper and lower attached stems, reciprocates for opening and closing the valve to fluid flow. A piston, responsive to the hydraulic actuator controls, is attached to the upper stem for urging the gate to the open position upon application of hydraulic actuator fluid pressure. A spring is arranged in the valve housing to assist the internal valve pressure on the stem in urging the gate to its closed position in the event of loss of hydraulic actuator fluid pressure. A lower detached stem is disposed in the valve chamber below the lower attached stem and is responsive to ambient sea pressure. When the ambient sea pressure becomes greater than the internal valve pressure, the lower detached stem engages the lower attached stem. A second spring is disposed below the lower detached stem to overcome frictional forces between the lower detached stem and seals in the valve housing when the lower detached stem moves to its engagement position. A port extends through the valve housing from between the lower attached and detached stems to the side of the valve opposite the side of the valve connected to the short section allowing fluid between the lower attached and detached stems to be displaced as the gate moves downwardly to the open position or as the lower detached stem moves upwardly to engage the lower attached stem. Thus, by venting the internal valve pressure through the port, pressure lock is avoided where internal valve fluids otherwise would be prevented from being displaced from the valve chamber.

Fail-safe, non-pressure locking gate valve

A valve comprising a housing with an inlet and outlet and a chamber in between, a reciprocating gate mounted in a gate seat disposed within the chamber for opening and closing the valve, an upper bonnet for closing the chamber at one end and a lower bonnet for closing the chamber at the other end, the gate being disposed between upper and lower stems which extend into the upper and lower bonnets respectively. Metal-to-metal seals are provided at all junctures between the above members in the lower gate position with back-up seals at the junctures of all moving members. A double edged seal ring integral with the upper stem self-contained within the upper bonnet provides a metal-to-metal seal with the upper bonnet in the upper and lower gate positions of the valve. A metal gasket arrangement is provided between the upper bonnet and valve body whereby the assemblage of all points of contact between the gasket and body form an annular ring. A combination seal ring of metal and plastic is disposed between the gate seat and valve body at the outlet whereby the metal prevents the plastic from extruding between the seat and body and into the outlet. A removable backseat may be used to simultaneously seal the upper bonnet and upper stem upon moving the valve to one of its positions.

Single double backseat

Extended casing method and apparatus for completing an underwater well whereby complete and continuous pressure control is maintained at the surface drilling platform. A conductor casing is installed in the floor of a body of water with a casing head and riser attached near the floor. Other casing is installed and supported at the water floor by hanger heads and having other risers extending upwardly therefrom. Pressure control equipment is installed at the upper end of one of the risers. An innermost casing having a tubing hanger-head attached is lowered through the pressure control equipment and installed. An orientation sleeve is aligned with the tubing hanger-head to properly orient the tubing hanger. The tubing hanger and tubing is then passed through the pressure control equipment and the innermost riser, to which the pressure control equipment is attached, and is lowered to engage the orientation sleeve for proper alignment with the innermost hanger-head and remotely latched thereto. All seals are then pressure tested. The tubing is plugged, the riser and control equipment removed and a Christmas tree adapter connected to the tubing hanger-head. A Christmas tree assembly is then attached to the adapter in fluidtight flow communication with the tubing string.

Underwater well completion method and apparatus

High pressure valve

A hydraulic control system for controlling a plurality of remotely positioned hydraulically actuated underwater devices by a single hydraulic control line extending underwater. A reference hydraulic manifold is connected to the single control line and a signal hydraulic manifold is connected to the single control line. A pilot actuated hydraulic control valve is connected to each of the underwater devices controlling the flow of actuating fluid thereto. The pilot of each valve is connected to both the reference manifold and the signal manifold, but the pilot of each of the valves is actuated by different pressure levels in the signal manifold whereby the underwater devices may be controlled in a predetermined sequence by applying predetermined pressure levels to the single hydraulic control line. A pressure regulator is positioned in the control line upstream of the reference manifold to maintain the reference manifold at a predetermined pressure level. Time delay and fail safe circuits are provided in the reference manifold and signal manifold. In one embodiment the hydraulic control valves are connected to provide one mode of sequencing the underwater devices. In another embodiment the hydraulic control valves are connected to provide a different mode of sequencing.

Hydraulic control system for controlling a plurality of underwater

Extended casing method and apparatus for completing an underwater well whereby complete and continuous pressure control is maintained at the surface drilling platform. A conductor casing is installed in the floor of a body of water with a casing head and riser attached near the floor. Other casing is installed and supported at the water floor by hanger heads and having other risers extending upwardly therefrom. Pressure control equipment is installed at the upper end of one of the risers. An innermost casing having a tubing hanger-head attached is lowered through the pressure control equipment and installed. An orientation sleeve is aligned with the tubing hanger-head to properly orient the tubing hanger. The tubing hanger and tubing, is then passed through the pressure control equipment and the innermost riser, to which the pressure control equipment is attached and is lowered to engage the orientation sleeve for proper alignment with the innermost hanger-head and remotely latched thereto. All seals are then pressure tested. The tubing is plugged, the riser and control equipment removed and a Christmas tree adapter connected to the tubing hanger-head. A Christmas tree assembly is then attached to the adapter in fluidtight flow communication with the tubing string.

Extended casing method and apparatus for completing an underwater well whereby complete and continuous pressure control is maintained at the surface drilling platform. A conductor casing is installed in the floor of a body of water with a casing head and riser attached near the floor. Other casing is installed and supported at the water floor by hanger heads and having other risers extending upwardly therefrom. Pressure control equipment is installed at the upper end of one of the risers. An innermost casing having a tubing hanger-head attached is lowered through the pressure control equipment and installed. An orientation sleeve is aligned with the tubing hanger-head to properly orient the tubing hanger. The tubing hanger and tubing is then passed through the pressure control equipment and the innermost riser, to which the pressure control equipment is attached, and is lowered to engage the orientation sleeve for proper alignment with the innermost hanger-head and remotely latched thereto. All seals are then pressure tested. The tubing is plugged, the riser and control equipment removed and a Christmas tree adapter connected to the tubing hanger head. A assembly is then attached to the adapter in fluidtight flow communication with the tubing string.

A balanced stem fail-safe valve controls flow of fluids through a submerged pipeline. A closed subsea hydraulic pressure system operates or powers the valve. In the fail-safe mode the operating or reservoir pressure equals ambient sea pressure. A valve housing is arranged on the pipeline and a valve chamber is formed in the valve housing. A valve element is movable in the valve chamber between open and closed positions to control the flow of fluids through the pipeline. A first fluid pressure operable means is connected to the valve element to move the valve element to open position upon application of pump pressure to the first fluid pressure operable means. Electrically operated valves are used to direct the flow of power fluid to and from the valve. A spring is arranged in the valve housing to urge the valve element to its closed position in the event of power failure. A second fluid pressure operable means detached from the valve element engages the valve element upon application of operating or reservoir pressure to the second fluid pressure operable means to balance any unwanted force which might occur when the ambient pressure is greater than the internal valve pressure and permit the spring to close the valve element. The valve operator may be removable by means of a remotely operated manipulator for repair or replacement of the valve system or portions thereof.

Growing community of inventors

Houston, TX, United States of America

David P Herd