| Patents for E21B 34 - Valve arrangements for boreholes or wells (14,685) |
|---|
| 07/02/1991 | CA1285471C Well testing apparatus and methods |
| 06/25/1991 | CA1285264C Downhole device for oil/gas wells |
| 06/19/1991 | EP0432873A2 Pressure balanced cartridge choke valve |
| 06/18/1991 | USRE33614 Apparatus and method for enhanced oil recovery |
| 06/18/1991 | US5024274 Method and apparatus for enhanced oil recovery |
| 06/18/1991 | US5024273 Cementing apparatus and method |
| 06/12/1991 | EP0431162A1 By-pass valve for boring column |
| 06/12/1991 | CN2078794U Safety means of pressure-testing plugging device in well head |
| 06/12/1991 | CA2031168A1 Valving system for inflatable packers |
| 06/05/1991 | CN2078368U High-grade general extraction liquid-injection valve |
| 06/05/1991 | CN1051958A Casing valve |
| 06/04/1991 | US5020600 Method and apparatus for chemical treatment of subterranean well bores |
| 06/04/1991 | US5020592 Tool for treating subterranean wells |
| 05/28/1991 | US5018581 Sand release apparatus and method |
| 05/22/1991 | CN1051607A Method of well completion |
| 05/16/1991 | WO1991006743A1 Bottom hole blowout preventer |
| 05/15/1991 | EP0427422A2 Casing valve |
| 05/15/1991 | EP0427371A1 Method of well completion |
| 05/15/1991 | EP0426915A1 Valve with removable insert |
| 05/14/1991 | CA1284099C Packer bypass |
| 05/07/1991 | US5012871 Fluid flow control system, assembly and method for oil and gas wells |
| 05/07/1991 | US5012867 Well flow control system |
| 05/07/1991 | US5012866 Drill stem mud wiping apparatus |
| 05/07/1991 | US5012865 Annular and concentric flow wellhead isolation tool |
| 05/07/1991 | US5012854 Pressure release valve for a subsea blowout preventer |
| 05/02/1991 | EP0424452A1 Plug for well logging operations. |
| 04/30/1991 | US5010956 Subsea tree cap well choke system |
| 04/24/1991 | CA2001387A1 Bottom hole blowout preventer |
| 04/18/1991 | WO1991005134A1 Cementing apparatus |
| 04/16/1991 | US5008664 Apparatus for inductively coupling signals between a downhole sensor and the surface |
| 04/16/1991 | CA1283042C Annulus pressure operated vent assembly |
| 04/09/1991 | US5005649 Multiple fracture production device and method |
| 04/02/1991 | US5004007 Chemical injection valve |
| 03/20/1991 | EP0417877A1 Shearing gate valve |
| 03/20/1991 | CN2073473U Heat-washing valve |
| 03/19/1991 | US5000264 Method and means for introducing treatment fluid into a subterranean formation |
| 03/13/1991 | EP0416719A1 Shearing gate valve |
| 03/12/1991 | CA1281280C Annular and concentric flow wellhead isolation tool and method of use thereof |
| 03/05/1991 | US4997162 Shearing gate valve |
| 03/05/1991 | US4997038 Lock mandrel latch assembly |
| 02/27/1991 | EP0290560B1 Shut down valve for use in a subwater position |
| 02/27/1991 | CN1049542A Rope core drilling tool |
| 02/26/1991 | US4995462 Dewaxing control apparatus for oil well |
| 02/22/1991 | CA2023640A1 Drill stem mud wiping apparatus |
| 02/20/1991 | EP0413628A1 Well testing apparatus |
| 02/19/1991 | US4993493 Retrievable landing method and assembly for a well bore |
| 02/12/1991 | US4991654 A sliding sleeve |
| 02/06/1991 | EP0411059A1 Removal of accumulated liquids in hydrocarbon wells |
| 02/05/1991 | US4990233 Method for retarding mineral buildup in downhole pumps |
| 01/30/1991 | CN2070354U Washing liquid-saving petroleum pipe end |
| 01/30/1991 | CN1011431B Anti-lifting safety device by interlocking the anti-gush and the brake of a drilling machine |
| 01/29/1991 | CA1279571C Well tool lock mandrel and handling tools therefor |
| 01/23/1991 | EP0409633A1 An actuator |
| 01/23/1991 | EP0409547A2 Inflatable straddle packer |
| 01/22/1991 | US4986358 Flapper mount for well safety valve |
| 01/22/1991 | US4986357 Subsurface |
| 01/22/1991 | US4986301 Sub-sea valve actuator |
| 01/17/1991 | DE3922379A1 Cut=off arrangement for artesian well - has shut=off valve in pipe packing which can be directly opened from sample extracting pipe above ground level |
| 01/16/1991 | CN1048579A Combined multifunctional oil wellhead assembly |
| 01/10/1991 | WO1991000412A1 By-pass valve for boring column |
| 01/10/1991 | WO1990012196A3 Method and apparatus for monitoring well fluid parameters |
| 01/10/1991 | DE3920392A1 Verfahren zum abbau und zur foerderung einer unter wasser lagernden bodenschicht und vorrichtung zur durchfuehrung des verfahrens A method for degrading and foerderung a ground layer overlying underwater and apparatus for performing the method |
| 01/09/1991 | CN1048436A Gas pressure balance and safety in pumping unit |
| 01/08/1991 | US4983803 Method of making a subsurface well safety valve |
| 01/01/1991 | US4981177 Method and apparatus for establishing communication with a downhole portion of a control fluid pipe |
| 01/01/1991 | US4981173 Electric surface controlled subsurface valve system |
| 12/25/1990 | US4979569 Dual action valve including at least two pressure responsive members |
| 12/25/1990 | US4979568 Annulus fluid pressure operated testing valve |
| 12/25/1990 | US4979566 Running tool for installing a casing hanger in a subsea tubular conductor |
| 12/18/1990 | US4977958 Downhole pump filter |
| 12/18/1990 | US4977957 Subsurface well safety valve with light weight components |
| 12/13/1990 | WO1990013764A3 Ball valve actuating member with force multiplier |
| 12/13/1990 | WO1990013731A3 Well control apparatus |
| 12/13/1990 | WO1990011429A3 Drill stem test tools |
| 12/11/1990 | US4976317 Well tool hydrostatic release means |
| 12/06/1990 | DE4017775A1 Verfahren und vorrichtung zum ausbau eines unterirdischen bohrloches Method and apparatus for the expansion of a subterranean well |
| 12/04/1990 | US4974690 Adapter for drilling strings with controllable air passage |
| 12/02/1990 | CA2018054A1 Apparatus for completion of a subterranean well |
| 11/28/1990 | EP0399890A1 Apparatus for testing an oil well, and corresponding method |
| 11/28/1990 | CN2066484U Well pressing device with one-way valve for open or close |
| 11/27/1990 | CA1276874C Subsurface device actuators |
| 11/22/1990 | EP0398838A1 Injection tube with anchor effect |
| 11/22/1990 | EP0397771A1 Clamped body replacement tool |
| 11/20/1990 | US4971099 Pressure balanced cartridge choke valve |
| 11/15/1990 | WO1990013764A2 Ball valve actuating member with force multiplier |
| 11/14/1990 | CN1046956A Manual port closing tool for well cmenting |
| 11/13/1990 | US4969524 Well completion assembly |
| 11/13/1990 | US4969515 Expendable devices for well lock system |
| 11/06/1990 | US4967845 Lock open mechanism for downhole safety valve |
| 11/06/1990 | US4967844 Selectively operable ball valve and production packer system |
| 11/06/1990 | US4967842 Sub surface safety valve block, particularly suitable for the risers of offshore platforms |
| 10/31/1990 | CN2064820U Oil field water injection wellhead check valve |
| 10/31/1990 | CN2064819U Combined multifunctional oil production wellhead assembly |
| 10/29/1990 | WO1990013731A2 Well control apparatus |
| 10/28/1990 | CA2015592A1 Method and apparatus for chemical treatment of subterranean well bores |
| 10/23/1990 | US4964460 Shut-in tool |
| 10/18/1990 | WO1990012196A2 Method and apparatus for monitoring well fluid parameters |
| 10/16/1990 | US4962815 Inflatable straddle packer |
| 10/16/1990 | US4962813 Well tool locking system for staggered bore |
| 10/16/1990 | US4962812 Tubular system for use in packing off a well bore |