1
Donald H Van Steenwyk, Ira N Childress: Catheter locating device. Applied Medical Devices, Christie Parker & Hale, November 6, 1979: US04173228 (334 worldwide citation)

A system for detecting and monitoring the position of a catheter tip during insertion and after placement of the catheter in a body cavity. A coupling means such as an inductor coil is secured adjacent the catheter tip, and leads extend from the coil along the catheter for connection to external ind ...


2
Donald H Van Steenwyk, James N Towle, Timothy Price: Apparatus and method for electric field telemetry employing component upper and lower housings in a well pipestring. Scientific Drilling International, William W Haefliger, March 16, 1999: US05883516 (59 worldwide citation)

An apparatus for borehole electric field telemetry includes a source of modulated voltage or current, at least one axially extending collar connected between pipe sections in a pipe string, and a system of insulated wireline components providing electrical connections, insulated from drilling fluids ...


3
Donald H Van Steenwyk: Direct switching modulation for electromagnetic borehole telemetry. Scientific Drilling International, William W Haefliger, July 14, 1992: US05130706 (58 worldwide citation)

An apparatus for borehole electromagnetic telemetry is provided comprising a direct switching element to couple energy from a downhole energy source to the earth-drillstring system, a downhole energy source that may be adapted to a variety of voltage levels, a system to control the switching element ...


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Donald H Van Steenwyk, James N Towle, Timothy Price: Electric field borehole telemetry. Scientific Drilling International, William W Haefliger, February 13, 2001: US06188223 (43 worldwide citation)

An apparatus for borehole electric field telemetry includes a source of modulated voltage or current, at least one axially extending collar collar connected between pipe sections in a pipe string, and a system of insulated wireline components providing electrical connections, insulated from drilling ...


6
Timothy M Price, Donald H Van Steenwyk: Casing joint detector. Applied Technologies Associates, Christie Parker & Hale, February 24, 1998: US05720345 (36 worldwide citation)

A borehole instrument that detects the joints of successive axial lengths of magnetic material enclosing a borehole while traveling along the inside of the enclosure by detecting anomalous magnetic fields indicative of the enclosure's joints. One embodiment of the invention is to measure the distanc ...


7
Donald H Van Steenwyk, James N Towle, Timothy Price: Apparatus and method for electric field telemetry employing component upper and lower housings in a well pipestring. Scientific Drilling International, William W Haefliger, May 28, 2002: US06396276 (36 worldwide citation)

An apparatus for borehole electric-field telemetry that comprises a source of modulated voltage or current, at least one axially non-conductive collar connected between pipe sections in a pipe string, and a system of insulated wireline components providing electrical connections, insulated from dril ...


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Donald H Van Steenwyk, Michael S Orcutt Clenard, Raymond W Teys: Wireline wet connection. Scientific Drilling International, William W Haefliger, February 14, 1995: US05389003 (30 worldwide citation)

A releasable and reseatable electrical connection between female and male members associated with disconnectible sections of wireline used in a drill string in a borehole comprising the male member defining a first axis and having an externally exposed electrical contact ring, extending about the ax ...


10
Donald H Van Steenwyk, John R Cash, Paul W Ott: Survey apparatus and method employing rate-of-turn and free gyroscopes. Applied Technologies Associates, William W Haefliger, November 3, 1981: US04297790 (29 worldwide citation)

Survey apparatus and method employs a free gyroscope for fast determination of azimuth, free gyroscope alignment being periodically corrected by a rate gyroscope which is periodically rotated for accurate azimuth determination. An accelerometer is also usable in conjunction with the gyroscopes for t ...