| Patents for E21B 34 - Valve arrangements for boreholes or wells (14,685) |
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| 02/27/1990 | US4903775 Well surging method and apparatus with mechanical actuating backup |
| 02/22/1990 | WO1990001611A1 Removal of accumulated liquids in hydrocarbon wells |
| 02/21/1990 | EP0354979A2 Downhole shuttle valve for wells |
| 02/20/1990 | US4901798 Apparatus and method for removal of accumulated liquids in hydrocarbon producing wells |
| 02/20/1990 | US4901752 Apparatus for maintenance of ball valve |
| 02/20/1990 | CA1265996A2 Hydraulically operable control unit |
| 02/20/1990 | CA1265995A1 Surface controlled subsurface safety valve |
| 02/20/1990 | CA1265993A1 Tubing isolation disc valve |
| 02/13/1990 | US4899821 Method and apparatus for servicing well casing and the like |
| 02/07/1990 | EP0353275A1 Shut-in tool. |
| 02/06/1990 | US4898241 Method and device for taking measurements and/or carrying out interventions in a well subjected to hydraulic compression |
| 02/06/1990 | US4898236 Drill stem testing system |
| 02/06/1990 | CA1265439A2 Method for production testing of a well |
| 02/06/1990 | CA1265438A2 Ball valve apparatus |
| 01/30/1990 | US4896722 Multiple well tool control systems in a multi-valve well testing system having automatic control modes |
| 01/25/1990 | WO1990000668A1 Well backsurging apparatus and method |
| 01/25/1990 | WO1990000667A1 Plug for well logging operations |
| 01/24/1990 | CN2051667U Automatic valve for oil pumping wells |
| 01/23/1990 | CA1264656A1 Full-bore sample-collecting apparatus |
| 01/10/1990 | EP0349685A1 Annulus valve for concentric tubing hangers |
| 01/02/1990 | US4890674 Flapper valve protection |
| 12/26/1989 | US4889199 Downhole valve for use when drilling an oil or gas well |
| 12/26/1989 | US4889184 Polished rod stuffing box with safety valve for a beam pumped production well |
| 12/20/1989 | EP0347050A2 Tubing conveyed downhole sampler |
| 12/19/1989 | US4887672 Subsea wellhead with annulus communicating system |
| 12/13/1989 | CN1037945A Sub surface safety valve block,particularly suitable for the risers of offshore platforms |
| 12/12/1989 | US4886114 Electric surface controlled subsurface valve system |
| 12/07/1989 | DE3809401C1 Method of fitting an underground safety valve in the delivery line of an underground gas reservoir |
| 11/29/1989 | EP0344060A2 Well tool control system and method |
| 11/29/1989 | CN2048511U Dual water tap |
| 11/28/1989 | US4883123 Above packer perforate, test and sample tool and method of use |
| 11/14/1989 | US4880062 Oil well downhole liquid injection assembly |
| 11/14/1989 | US4880060 Valve control system |
| 11/14/1989 | US4880059 Sliding sleeve casing tool |
| 11/14/1989 | US4880058 Stage cementing valve |
| 11/14/1989 | US4880056 Hydraulically activated firing head for well perforating guns |
| 11/08/1989 | CN2047301U Well stabilization single pass valve |
| 11/07/1989 | US4878538 Perforate, test and sample tool and method of use |
| 10/31/1989 | US4878053 Actuation method |
| 10/31/1989 | US4877217 Fail-safe blowout preventer |
| 10/31/1989 | US4877095 Stopper for cable passages or conduits |
| 10/25/1989 | EP0338030A1 Apparatus for maintenance of ball valve |
| 10/18/1989 | CN1036431A Drill stem test method and apparatus |
| 10/17/1989 | US4874008 Valve mounting and block manifold |
| 10/11/1989 | EP0336010A1 Percussion drill with interchangeable downhole or sideways discharging cutting or drilling head |
| 10/03/1989 | US4871019 Wellbore fluid sampling apparatus |
| 09/27/1989 | EP0333955A1 Wellhead valve |
| 09/26/1989 | US4869318 Annulus valve for concentric tubing hangers |
| 09/26/1989 | CA1261176A1 Method of, and measuring tube and measuring probe for, measuring fluid pressure in a sealed bore hole |
| 09/26/1989 | CA1260384A1 Subsea master valve for use in well testing |
| 09/26/1989 | CA1260376A1 Wear resistant diamond cladding |
| 09/26/1989 | CA1259908A1 Non-return valve |
| 09/19/1989 | US4867242 Method and apparatus for breaking gas lock in oil well pumps |
| 09/12/1989 | CA1259224A1 Gas-lock breaking device |
| 09/06/1989 | EP0331227A1 Sub surface safety valve block, particularly suitable for the risers of offshore platforms |
| 09/05/1989 | US4862965 Threadless well tool and method of making |
| 09/05/1989 | US4862964 Method and apparatus for perforating well bores using differential pressure |
| 09/05/1989 | US4862915 Rotary actuated disc valve |
| 08/29/1989 | US4860991 Safety valve |
| 08/22/1989 | US4858692 Cementing apparatus and method for execution of cementing operation |
| 08/22/1989 | US4858690 Upward movement only actuated gravel pack system |
| 08/22/1989 | US4858644 Fluid flow regulator |
| 08/15/1989 | US4856756 Well bottom release valve |
| 08/15/1989 | US4856595 Well tool control system and method |
| 08/15/1989 | US4856585 Tubing conveyed sampler |
| 08/15/1989 | US4856583 Apparatus for treating well bores |
| 08/10/1989 | WO1989007191A1 Clamped body replacement tool |
| 08/09/1989 | EP0327432A2 Process and device for hydraulically and selectively controlling at least two tools or instruments of a device, valve for carrying out this method or for using this device |
| 08/09/1989 | EP0327405A1 Well cementing stage tool and method and device for alleviating a hydraulic lock |
| 08/08/1989 | US4854387 Large bore retrievable well safety valve |
| 08/01/1989 | US4852648 Well installation in which electrical current is supplied for a source at the wellhead to an electrically responsive device located a substantial distance below the wellhead |
| 07/27/1989 | WO1989006740A1 Shut-in tool |
| 07/25/1989 | US4850432 Manual port closing tool for well cementing |
| 07/18/1989 | US4848473 Subsea well choke system |
| 07/18/1989 | US4848472 Insert choke and control module therefor |
| 07/18/1989 | US4848463 Surface read-out tester valve and probe |
| 07/18/1989 | US4848457 Annulus sliding sleeve valve |
| 07/18/1989 | US4848454 Downhole tool for use with a ball and seat traveling valve for a fluid pump |
| 07/18/1989 | US4848401 Isolation chamber valve |
| 07/18/1989 | US4848399 First out pneumatic indicator valve |
| 07/18/1989 | CA1257538A2 Surface controlled subsurface safety valve |
| 07/11/1989 | US4846281 Dual flapper valve assembly |
| 07/11/1989 | US4846280 Drill stem test method and apparatus |
| 07/11/1989 | US4846272 Downhole shuttle valve for wells |
| 07/06/1989 | DE3740367C1 Seat ring for ball cocks mounted in a floating manner, having a sealing element which blocks on one side |
| 07/04/1989 | US4844166 Method and apparatus for recompleting wells with coil tubing |
| 06/28/1989 | EP0321610A1 Oil well safety valve and setting and retrieving tools for such a valve |
| 06/28/1989 | EP0321609A1 Oil well safety valve and tool for installing such a valve |
| 06/27/1989 | US4842074 Gas storage well safety system and method |
| 06/27/1989 | US4842064 Well testing apparatus and methods |
| 06/27/1989 | US4842062 Hydraulic lock alleviation device, well cementing stage tool, and related methods |
| 06/20/1989 | US4840346 Apparatus for sealing a well blowout |
| 06/20/1989 | US4840229 Multiple position service seal unit with positive position indicating means |
| 06/13/1989 | US4838355 Dual hydraulic safety valve |
| 06/13/1989 | CA1255780A2 Well production controller system |
| 06/08/1989 | DE3740368A1 Seat ring seal for ball valves |
| 06/06/1989 | USH635 Injection mandrel |
| 06/06/1989 | US4836287 Safety gate valve for petroleum wells, permitting operation by artificial flow |
| 06/06/1989 | CA1255375A1 Verification of a surface controlled subsurface actuating device |
| 05/30/1989 | US4834183 Surface controlled subsurface safety valve |