| Patents for E21B 47 - Survey of boreholes or wells (31,352) |
|---|
| 01/14/1992 | US5081613 Method of identification of well damage and downhole irregularities |
| 01/11/1992 | CA2046229A1 Method and apparatus for determining the torque applied to a drillstring at the surface |
| 01/10/1992 | CA2046470A1 Method and apparatus for actuating a downhole tool |
| 01/09/1992 | WO1991019075A3 Double-tube core drill for inclined drilling |
| 01/08/1992 | EP0465316A1 Apparatus for stimulating production and for logging for non-eruptive wells |
| 01/08/1992 | EP0464346A1 Device to determine linear deformations of a medium along a measuring line |
| 01/07/1992 | US5079750 Method and apparatus for transmitting information in a borehole employing discrimination |
| 01/07/1992 | CA1294067C Method for determining depth of penetration of radioactive tracersin formation fractures |
| 01/07/1992 | CA1294022C Method and apparatus for controlling a well pumping unit |
| 12/31/1991 | US5077471 Method and apparatus for measuring horizontal fluid flow in downhole formations using injected radioactive tracer monitoring |
| 12/27/1991 | EP0462803A2 Method and apparatus for determining oil/water mixtures in a well borehole |
| 12/26/1991 | WO1991020002A1 An improved system for locating concealed underground objects |
| 12/26/1991 | WO1991019954A1 Angle sensor for a steerable boring tool |
| 12/25/1991 | CN2091455U Rotary convert instrument |
| 12/24/1991 | US5074365 Producing drainage |
| 12/24/1991 | US5074359 Method for hydraulic fracturing cased wellbores |
| 12/20/1991 | CA2044944A1 Dielectric measuring apparatus for determining oil and water mixtures in a well borehole |
| 12/18/1991 | EP0461963A1 Method and device for logging non-eruptive wells |
| 12/18/1991 | EP0461321A1 Apparatus and method for analyzing the composition of formation fluids |
| 12/17/1991 | US5073877 For use in a pipe string having a bore suspended in a well |
| 12/17/1991 | CA1293296C Apparatus for electromagnetically coupling power and data signals between well bore apparatus and the surface |
| 12/16/1991 | WO1991019884A1 Video logging system having remote power source |
| 12/11/1991 | CN1015067B Ring-drop testing method of oil-extracting well without shutdown |
| 12/10/1991 | US5072404 Method of tracking fluids flowing along a flow path |
| 12/10/1991 | US5072388 Lined casing inspection method |
| 12/10/1991 | US5072387 Method for determining a transit time for a radioactive tracer |
| 12/10/1991 | US5070949 Method of analyzing fluid influxes in hydrocarbon wells |
| 12/10/1991 | US5070725 Water-cut monitoring means and method |
| 12/03/1991 | US5070462 Device for locating a boring machine |
| 12/03/1991 | US5070249 Photomultiplier tube mounting for well logging detectors |
| 12/01/1991 | WO1991019075A2 Double-tube core drill for inclined drilling |
| 12/01/1991 | CA2083827A1 Double-tube core drill for inclined drilling |
| 11/28/1991 | WO1991018262A1 Method for measuring the azimuth of a drillhole |
| 11/27/1991 | CN2089523U Mud filtering and removing device for signal channel interference |
| 11/26/1991 | CA1292427C Method of locating hydrocarbon producing strata and the instrument therefor |
| 11/21/1991 | EP0457650A2 Ultrasonic measurement apparatus and method for boreholes |
| 11/21/1991 | EP0457628A2 Nuclear activation method and apparatus for detecting and quantifying earth elements |
| 11/20/1991 | CN2089069U Frost proof pressure gauge base for water well |
| 11/19/1991 | US5067114 Correlation for combinational coded telemetry |
| 11/19/1991 | US5065825 Method and device for remote-controlling drill string equipment by a sequence of information |
| 11/19/1991 | US5065619 Method for testing a cased hole formation |
| 11/13/1991 | EP0456415A2 Control apparatus and method responsive to a changing stimulus |
| 11/12/1991 | US5064349 Method of monitoring and controlling a pumped well |
| 11/12/1991 | US5064348 Determination of well pumping system downtime |
| 11/12/1991 | US5064006 Downhole combination tool |
| 11/12/1991 | US5063778 Apparatus for measuring the level of a liquid in a wetwell |
| 11/12/1991 | US5063775 Method and system for controlling a mechanical pump to monitor and optimize both reservoir and equipment performance |
| 11/12/1991 | US5063772 Method for troubleshooting gas-lift wells |
| 11/07/1991 | DE4114784A1 Guiding tool along subterranean path e.g. under river |
| 11/05/1991 | US5062482 Piezometer actuator device and method for its installation in a borehole |
| 11/05/1991 | CA2041622A1 Guiding of a tool along a subterranean path |
| 10/31/1991 | WO1991016525A1 System for controlling direction of underground excavator |
| 10/30/1991 | EP0454560A1 Wireline and coiled tubing retrievable choke for downhole flow measurement |
| 10/30/1991 | CN2087782U Rubber cup type antifreezing device for pressure gage |
| 10/29/1991 | US5062048 Stretch corrected wireline depth measuring error and log quality indicator method and apparatus |
| 10/29/1991 | US5061849 Externally mounted radioactivity detector for MWD employing radial inline scintillator and photomultiplier tube |
| 10/29/1991 | US5060737 Drilling system |
| 10/29/1991 | US5060728 Process for preventing scale formation in oil wells |
| 10/29/1991 | CA1291557C Surface acoustic wave pipe identification system |
| 10/24/1991 | DE4012625A1 Water sample extractor for bore - has operating unit providing bidirectional optical data transfer for programming and sensor information |
| 10/23/1991 | EP0453052A2 Well bore measurement tool |
| 10/23/1991 | EP0453051A2 Well bore measurement tool |
| 10/17/1991 | WO1991015740A1 Integrated sensor-transducer device and pressure sensor-transducer |
| 10/16/1991 | EP0452126A2 Apparatus for orienting perforating gun |
| 10/16/1991 | EP0452044A2 Multiple caliper arm downhole tool |
| 10/16/1991 | CN2086792U Centralising apparatus for oil well logging |
| 10/15/1991 | US5058077 Compensation technique for eccentered MWD sensors |
| 10/15/1991 | US5057021 Arrow-plot with color coded azimuth |
| 10/15/1991 | US5056600 Control apparatus and method responsive to a changing stimulus |
| 10/15/1991 | CA1290669C Method for determining residual oil saturation |
| 10/15/1991 | CA1290668C Process for determining residual oil saturation |
| 10/13/1991 | CA2040299A1 Method for discriminating microphonic noise in proportional counters |
| 10/11/1991 | CA2040057A1 Multiple caliper arms capable of independent movement |
| 10/09/1991 | EP0450207A1 Downhole drilling tool system |
| 10/08/1991 | USRE33708 Surveying of boreholes using shortened non-magnetic collars |
| 10/08/1991 | US5056067 Analog circuit for controlling acoustic transducer arrays |
| 10/08/1991 | US5055837 Analysis and identification of a drilling fluid column based on decoding of measurement-while-drilling signals |
| 10/08/1991 | US5055675 Pulse height analyzer for spectroscopy thermal multigate decay well logging system |
| 10/08/1991 | US5054557 Device for extracting a liquid out of a tube of great length |
| 10/08/1991 | CA1290468C Method for detecting drilling fluid in the annulus of a cased wellbore |
| 10/08/1991 | CA1290467C Methods and apparatus for safely measuring downhole conditions and formation characteristics while drilling a borehole |
| 10/02/1991 | EP0449710A2 Video system and method for determining and monitoring the depth of a bottomhole assembly within a wellbore |
| 10/02/1991 | EP0448845A1 Measure while drilling system |
| 10/02/1991 | DE4006320C1 Straight line tunnel borer - has guide tube to which casing is connected with load-out conveyor |
| 10/01/1991 | US5052941 Inductive-coupling connector for a well head equipment |
| 10/01/1991 | US5052220 Apparatus for measurements related to fluid flow in a borehole |
| 10/01/1991 | CA2039406A1 Video system and method for determining and monitoring the depth of a bottomhole assembly within a borehole |
| 09/25/1991 | CN1054813A Method and system for controlling vibrations in borehole equipment |
| 09/25/1991 | CN1014097B System for acquiring and recording signals delivered by set of sensors disposed in well probes |
| 09/24/1991 | US5050675 Perforating and testing apparatus including a microprocessor implemented control system responsive to an output from an inductive coupler or other input stimulus |
| 09/24/1991 | CA2038850A1 Dipmeter responsive to phase shift differential |
| 09/24/1991 | CA1289464C Perforate, test and sample tool and method of use |
| 09/24/1991 | CA1289463C Well fluid sampling apparatus |
| 09/19/1991 | WO1991014079A1 System for detecting position of underground excavator and magnetic field producing cable |
| 09/18/1991 | EP0446360A1 Position detecting device for underground excavator |
| 09/18/1991 | CN2084979U Pressure measuring device for hydraulic piston pump oil well |
| 09/17/1991 | USRE33690 Level sensor |
| 09/17/1991 | US5050132 Acoustic data transmission method |
| 09/17/1991 | US5049037 Automatic well pump skimmer level control |
| 09/17/1991 | US5048619 Down-hole bearing assemblies |