Nam Thi Le

48906743, Jan 2, 1990

Dec 16, 1988

7/285517

Nam V. Le - Lewisville TX

Otis Engineering Corporation - Carrollton TX

E21B 3408
E21B 3410

166319

An improved subsurface safety valve has a flapper plate which is held open by an operator tube, and which can be closed rapidly during high flow operating conditions without damage to the flapper plate or to the operator tube. The operator tube is telescopically coupled within a tubular piston. Retraction of the operator tube relative to the piston is yieldably opposed by a compression wave spring which is interposed between the operator tube and the piston. Telescoping retraction of the operator tube within the piston is limited by engagement of the operator tube against an internal shoulder of the piston. Damage to the flapper closure plate, pivot pin and operator tube is avoided by effectively decoupling the operator tube from the inertia load presented by the hydraulic piston and column of hydraulic control fluid. This is achieved by telescoping retraction of the operator tube within the piston as the flapper plate rotates through the critical throttling region into sealing engagement against the flapper valve seat. Because of its lower inertia, the operator tube is retracted rapidly through the spring housing in response to rotation of the flapper plate, thereby substantially reducing the magnitude of reaction forces which arise during dragging engagement between the flapper plate and the curved edge of the operator tube.

55645020, Oct 15, 1996

Jan 30, 1995

8/381571

Robert W. Crow - Irving TX
John C. Gano - Carrollton TX
Nam V. Le - Lewisville TX
James R. Longbottom - Whitesboro TX
Karluf Hagen - Stavanger, NO

Halliburton Company - Dallas TX

E21B 3312

166386

A well control valve assembly prevents flow from or to completion segments further downhole from the well control valve assembly once the stimulation stimulation/shifter string has been removed from the production tubing string. The well control valve assembly features a shaped flapper plate which, when opened, conforms closely to the shape and size of the production tubing string's interior diameter. The flapper plate is biased toward a closed position by a compression spring arrangement that includes an arm which levers the plate upward toward a seating surface. The valve assembly's closure is mechanically induced and is not responsive to a sensed well condition.

60036052, Dec 21, 1999

Dec 1, 1997

8/980593

Rennie L. Dickson - Carrollton TX
Nam Van Le - Carrollton TX

Halliburton Enery Services, Inc. - Dallas TX

E21B 3410

166375

A tubing retrievable surface controlled subsurface safety valve 106 is adapted to be positioned in a well tubing string 102 to control the flow through the tubing string. The safety valve includes an annular housing or body 200 defining a fluid passageway through which fluids and/or gasses may flow to the surface. The safety valve is equipped with a valve closure member such as flapper 252, positioned in the fluid passageway which is moveable between an open and closed position. The valve closure member is engaged and actuated by a longitudinally extending operator 242 that engages the valve closure member 252. In one embodiment, the longitudinally extending operator 242 may be a tubular member longitudinally moveable within the valve body. The longitudinally extending member 242 is operatively coupled to a spring guide 226. A biasing spring 222 is positioned in a spring chamber 120 defined by a spring housing 228 and the spring guide 226.

58232656, Oct 20, 1998

Jul 19, 1996

8/683947

Robert W. Crow - Irving TX
John C. Gano - Carrollton TX
Nam Van Le - Lewisville TX
James R. Longbottom - Whitesboro TX
Karluf Hagen - Stavanger TX

Halliburton Energy Services, Inc. - Dallas TX

E21B 3406

166373

A system for selective production from, and stimulation of, subterranean production zones while improving productivity and enhancing control of the well. Portions of a production tubing string and an internal stimulation/shifter string are assembled and run together as completion segments. Consecutive completion segments, with each segment including packers that surround sleeves and terminate at the upper end in a well control valve, are run into the cased wellbore so that the acid flow ports operated by sleeve valve assemblies are placed proximate the perforations of prospective production zones. The production zones are then stimulated as the stimulation/shifter string is moved progressively outward placing acid at each consecutive zone. The stimulation/shifter string is then removed from the production tubing string, mechanically closing the well control valve assembly by tubing manipulation. A well control valve assembly prevents flow from or to completion segments further downhole from the well control valve assembly once the stimulation/shifter string has been removed from the production tubing string.

51599813, Nov 3, 1992

Jun 20, 1991

7/718214

Nam V. Le - Lewisville TX

Otis Engineering Corporation - Dallas TX

E21B 3406
F16K 1503

166325

A flapper valve assembly when closed permits flow through in one direction and prevents flow in the opposite direction. When open, two way flow may occur and the flapper valve member is biased toward closed position, to sealingly engage an annular seat, by one or more springs in the wall of the flapper valve housing. This structure provides a greater closing force applied to the flapper valve through a tension member connected to the flapper valve hinge. Three forms of tension members are disclosed.

50224271, Jun 11, 1991

Mar 2, 1990

7/487398

Ronald K. Churchman - Carrollton TX
Michael W. Meaders - Lewisville TX
Nam Van Le - Lewisville TX

Otis Engineering Corporation - Carrollton TX

F04F 120

137155

A lift gas safety valve has a compound valve closure assembly which will close automatically upon loss of hydraulic control pressure, and which can be reopened and maintained in the open position by the application of hydraulic control pressure at a relatively low pressure level. A primary valve closure member is slideably mounted onto a valve stem for movement to a seated position on the valve body in which a lift gas flow passage is closed, to an unseated position in which the lift gas flow passage is opened. A bypass flow passage is formed between the stem and the primary valve closure member for establishing fluid flow communication between the lift gas flow passage and the outlet port when the primary valve closure member is in its seated position. The auxiliary valve closure member is mounted onto the valve stem for movement from a seated position on the primary valve closure member to an unseated position for selectively closing and opening the bypass flow passage. According to this arrangement, when the auxiliary valve closure member is moved to its open position, the pressure differential across the safety valve is equalized, thereby permitting the main valve closure member to be unseated by the application of hydraulic control fluid at a relatively low pressure level.