1
Martin E Cobern: Method for evaluation of formation invasion and formation permeability. Teleco Oilfield Services, Fishman & Dionne, January 5, 1988: US04716973 (50 worldwide citation)

A method is presented for evaluation of formation invasion and formation permeability by conducting a series of formation resistivity loggings in the operation of a measurement while drilling (MWD) logging system.


2
Martin E Cobern: Mud turbine tachometer. Teleco Oilfield Services, Fishman & Dionne, March 3, 1987: US04647853 (38 worldwide citation)

In an MWD measurement system, the speed of rotation of a downhole turbine is measured by the interaction of a triaxial magnetometer in a sensor package and a permanent magnet attached to the turbine shaft. The triaxial magnetometer may be part of an existing MWD system for measuring borehole directi ...


3
Martin E Cobern: Method for deploying extendable arm for formation evaluation MWD tool. Baker Hughes Incorporated, Fishman Dionne & Cantor, September 7, 1993: US05242020 (37 worldwide citation)

An extending arm is incorporated into a formation evaluation MWD collar or sub for extending outwardly from the tool and maintaining direct and continuous contact with the borehole wall (e.g., formation). In accordance with this invention, a method is presented for intermittently deploying the exten ...


4
Martin E Cobern, Frederick A Stone, Edmund M Hamlin: Method for the detection and correction of magnetic interference in the surveying of boreholes. Teleco Oilfield Services, Fishman Dionne & Cantor, August 9, 1988: US04761889 (34 worldwide citation)

A method is presented, for use in borehole drilling, for correcting errors in azimuth determination resulting from variations in the earth's magnetic field to which a measuring instrument is exposed. The method distinguishes between variations in the earth's magnetic field caused by the drillstring ...


5
Richard D DiPersio, Martin E Cobern: Method for measurement of azimuth of a borehole while drilling. Teleco Oilfield Services, Fishman Dionne & Cantor, March 21, 1989: US04813274 (31 worldwide citation)

A method is presented for measuring the azimuth angle of a borehole being drilled, the data for determining the azimuth angle being obtained while the drillstring is rotating.


6
Martin E Cobern, Walter A Helm: Means for varying MWD tool operating modes from the surface. Teleco Oilfield Services, Fishman Dionne & Cantor, July 23, 1991: US05034929 (30 worldwide citation)

A method and apparatus for establishing a remote communications link from the rig floor to the downhole MWD system is presented. In accordance with the present invention, the state of a physical condition downhole is changed in a predetermined timed sequence. This state change is controlled on the s ...


7
Martin E Cobern, Richard D DiPersio, Edmund M Hamlin: Method and apparatus for measurement of azimuth of a borehole while drilling. Alcan International, Cooper & Dunham, January 23, 1990: US04894923 (27 worldwide citation)

A method and apparatus is presented for measuring the azimuth angle of a borehole being drilled, the data for determining the azimuth angle being obtained while the drillstring is rotating.


8
William E Turner, Carl A Perry, Mark E Wassell, Jason R Barbely, Daniel E Burgess, Martin E Cobern: Rotary steerable motor system for underground drilling. APS Technology, Woodcock Washburn, July 27, 2010: US07762356 (18 worldwide citation)

A preferred embodiment of a system for rotating and guiding a drill bit in an underground bore includes a drilling motor and a drive shaft coupled to drilling motor so that drill bit can be rotated by the drilling motor. The system further includes a guidance module having an actuating arm movable b ...


9
William E Turner, Carl A Perry, Mark E Wassell, Jason R Barbely, Daniel E Burgess, Martin E Cobern: Rotary steerable motor system for underground drilling. APS Technology, Woodcock Washburn, June 24, 2008: US07389830 (15 worldwide citation)

A preferred embodiment of a system for rotating and guiding a drill bit in an underground bore includes a drilling motor and a drive shaft coupled to drilling motor so that drill bit can be rotated by the drilling motor. The system further includes a guidance module having an actuating arm movable b ...


10
Martin E Cobern: Methods and systems for determining angular orientation of a drill string. APS Technology, Woodcock Washburn, March 23, 2010: US07681663 (13 worldwide citation)

Preferred methods and systems generate a control input based on a periodically-varying characteristic associated with the rotation of a drill string. The periodically varying characteristic can be correlated with the magnetic tool face and gravity tool face of a rotating component of the drill strin ...