David P Herd

US Patent:

20050067167, Mar 31, 2005

Filed:

Sep 25, 2003

Appl. No.:

10/671357

Inventors:

Douglas Hall - Houston TX, US
David Herd - Houston TX, US
Richard Buckenham - Singapore, SG

International Classification:

E21B043/16

US Classification:

166379000, 166305100, 166090100

Abstract:

Radial penetrator assembly conducts fluid through the passageway in the wall to a wellhead housing and into a port in a tubular hanger positioned within a central bore in the wellhead housing. The flexible tube extends between the passageway in the wellhead housing and the port in the inner member, while sleeve-shaped adapter extends radially from the wellhead housing and has an adapter bore sealed to a radial passageway in the wellhead housing. A radial outer seal seals between the radial outer portion of the adapter and a radially outer portion of the flexible tube . The flexibility of the tube permits an inner portion axis with the tube to be offset or slanted with respect to an outer portion axis of the tube.

US Patent:

42942845, Oct 13, 1981

Filed:

Nov 13, 1979

Appl. No.:

6/093612

Inventors:

David P. Herd - Kingwood TX

Assignee:

Smith International, Inc. - Newport Beach CA

International Classification:

F16K 31122
F16K 300

US Classification:

137613

Abstract:

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.

US Patent:

44510470, May 29, 1984

Filed:

Sep 30, 1982

Appl. No.:

6/429533

Inventors:

David P. Herd - Houston TX
Duane E. Gibson - Houston TX

Assignee:

Smith International, Inc. - Newport Beach CA

International Classification:

F16J 1518

US Classification:

277 26

Abstract:

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.

US Patent:

39333388, Jan 20, 1976

Filed:

Oct 21, 1974

Appl. No.:

5/516704

Inventors:

David P. Herd - Houston TX
John W. McCaskill - Houston TX
Thomas W. Childers - Mandeville LA

Assignee:

Exxon Production Research Company - Houston TX

International Classification:

F16K 31126

US Classification:

251 636

Abstract:

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.

US Patent:

43402046, Jul 20, 1982

Filed:

Sep 15, 1977

Appl. No.:

5/833684

Inventors:

David P. Herd - Houston TX

Assignee:

Smith International, Inc. - Newport Beach CA

International Classification:

F16K 4104
B65D 5302

US Classification:

251327

Abstract:

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.

US Patent:

39715760, Jul 27, 1976

Filed:

Aug 13, 1973

Appl. No.:

5/387667

Inventors:

David P. Herd - Houston TX
John H. Fowler - Pittsburgh PA

Assignee:

McEvoy Oilfield Equipment Co. - Houston TX

International Classification:

F16L 3724

US Classification:

285 87

Abstract:

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.

US Patent:

42720559, Jun 9, 1981

Filed:

Oct 13, 1978

Appl. No.:

5/951109

Inventors:

David P. Herd - Houston TX

Assignee:

McEvoy Oilfield Equipment Company - Houston TX

International Classification:

F16K 4116
F16K 4114

US Classification:

251214

Abstract:

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.

US Patent:

40292940, Jun 14, 1977

Filed:

Oct 4, 1974

Appl. No.:

5/512092

Inventors:

John Walton McCaskill - Houston TX
Robert D. Barnett - Magnolia TX
David P. Herd - Houston TX

Assignee:

McEvoy Oilfield Equipment Co. - Houston TX

International Classification:

F16K 522
F16K 4114

US Classification:

251282

Abstract:

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.