Bench Tree Group, LLC

Baker Hughes Corporation

Precision Energy Services, Inc.

Cidra Corporation

Precision Drilling Technology Services Group, Inc.

Other

Weatherford/lamb, Inc.

Weatherford Canada Patnership

Weatherford Canada Partnership

Jian-Qun Wu

Larry Wayne Thompson

Macmillan M Wisler

Alan D Kersey

Lee Jacobo Jose Roitberg

Lance Pate

James-Christian F Ang

Arthur D Hay

MacMillian M Wisler

Daniel L Gysling

James R Dunphy

John W Harrell

Andrew G Brooks

Robert J Maron

Michael Louis Larronde

Bob A Hardage

Roger P Bartel

Francis X Bostick, Iii

Allen R Davis

Phillip E Pruett

Peter C Ogle

Wallace H Meyer, Jr

Paul E Radzinski

Xiaomin Zhao

Kevin F Didden

Michael S Spencer

Lee Jacobo Roitberg

An improved total field calibration system and method is disclosed for reducing the rotational misalignment between magnetic and gravity sensors in a directional sensing system. A method of calibrating a tri-axial directional sensor comprising orthonormal accelerometers and orthonormal magnetometers, comprises measuring Earth's magnetic and gravity fields with said directional sensor in at least 4 sensor orientations; obtaining at least one reference field value of dip drift of Earth's magnetic field from at least one source independent of said directional sensor corresponding to said orientations; and, determining and applying rotational misalignments between said magnetometers and said accelerometers so that measured magnetic dip drifts are substantially equal to said reference values. The calibration process can be performed without monitoring the declination change during the calibration process. Directional sensing systems can be calibrated accurately during a period when the Earth's magnetic field changes rapidly.

System and method of directional sensor calibration

Slotted dipole antennas for use in an antenna system on a drill collar segment is presented. Dipoles may be placed in slots on the drill collar segment. A dipole consists of a ferrite rod with electric wires placed above and below the ferrite rod. Wires may be connected such that wire current forms a loop around the ferrite rod. When a group of slots are used for an antenna, wire holes are constructed between slots. Effectively a single wire may be used to go above all ferrite rods in the group and then turn to go below all the ferrite rods. Two wire segments are in a wire hole connecting two adjacent slots. Currents in the two segments are the same in magnitudes and flow in opposite directions. There is no net current in wires in a wire hole.

Electromagnetic tool using slotted point dipole antennas

Methods for sensing formation properties while drilling a well are described. An antenna system and transceiver electronics system are disposed on a drill collar segment. The antenna system includes at least one transmitter antenna for creating an electromagnetic field and at least one receiver antenna for detecting the electromagnetic field. At least one antenna in the antenna system is a magnetic dipole based antenna having at least two slot based magnetic dipoles. The slot based magnetic dipoles include slots in an outer surface of the drill collar segment, wire holes beneath the outer surface connecting the slots with each other and with the transceiver electronics system, a ferrite rod placed in each slot, and, at least one continuous antenna wire passing through the slots and the wire holes.

An electromagnetic tool using slotted dipole antennas is presented. The dipoles may be placed in slots on a drill collar. A receiver or transmitter antenna consists of one or more slots. A dipole consists of a ferrite rod with electric wires placed above and below the ferrite. Wires may be connected such that wire current forms a loop around the ferrite rod. When a group of slots are used for an antenna, wire holes are constructed between slots. Effectively a single wire may be used to go above all ferrite rods in the group and then turn to go below all the rods. Two wire segments are in a wire hole connecting two adjacent slots. Currents in the two segments are the same in magnitudes and flow in opposite directions. There is no net current in wires in a wire hole.

A steerable, magnetic dipole antenna for Measurement-While-Drilling (MWD) or Logging-While-Drilling (LWD) applications. The antenna elements use a hole arrangement in addition to grooves in a steel tool body, which is typically a drill collar. This antenna embodiment is extremely robust, meaning that does not significantly reduce the structural integrity of the tool body in which it is disposed. The antenna embodiment is also relatively wear resistant. The resultant magnetic dipole generated by this antenna is also electrically steerable in inclination angle from a common origin. A variable dipole moment inclination angle combined with independently measured tool rotation orientation during normal drilling allows the antenna to generate a magnetic dipole moment that may be directed at any three dimensional angle and from a common origin point at the centroid of the antenna.

Steerable magnetic dipole antenna for measurement while drilling applications

An improved total field calibration system and method is disclosed for reducing the rotational misalignment between magnetic and gravity sensors in a directional sensing system. A method of calibrating a tri-axial directional sensor that includes orthonormal accelerometers and orthonormal magnetometers is disclosed. The method includes measuring Earth's magnetic and gravity fields with said directional sensor in at least 4 sensor orientations; obtaining at least one reference field value of dip drift of Earth's magnetic field from at least one source independent of said directional sensor corresponding to said orientations; and, determining and applying rotational misalignments between said magnetometers and said accelerometers so that measured magnetic dip drifts are substantially equal to said reference values. The calibration process can be performed without monitoring the declination change during the calibration process. Directional sensing systems can be calibrated accurately during a period when the Earth's magnetic field changes rapidly.

An improved total field calibration system and method is disclosed for reducing the rotational misalignment between magnetic and gravity sensors in a directional sensing system. The effect of variation of surface components of the Earth's magnetic field during the calibration process on magnetometer misalignment may be completely eliminated by requiring the magnetic dip derived from the sensing system to match that of the Earth's field obtained from a reference source. The calibration process can be performed without monitoring the declination change during the calibration process. Directional sensing systems can be calibrated accurately during a period when the Earth's magnetic field changes rapidly.

A steerable or non-steerable, magnetic dipole antenna for Measurement-While-Drilling (MWD) or Logging-While-Drilling (LWD) applications. The antenna elements use a hole arrangement in addition to grooves in a steel tool body, which is typically a drill collar. This antenna embodiment is extremely robust, meaning that does not significantly reduce the structural integrity of the tool body in which it is disposed. The antenna embodiment is also relatively wear resistant. The resultant magnetic dipole generated by this antenna is also electrically steerable in inclination angle from a common origin. A variable dipole moment inclination angle combined with independently measured tool rotation orientation during normal drilling allows the antenna to generate a magnetic dipole moment that may be directed at any three dimensional angle and from a common origin point at the centroid of the antenna. The antenna can also be embodied to be more sensitive to resistivity in a particular azimuthal direction.

Steerable magnetic dipole antenna for measurement-while-drilling applications

A steerable, magnetic dipole antenna for Measurement-While-Drilling (MWD) or Logging-While-Drilling (LWD) applications. The antenna elements use a hole arrangement in addition to grooves in a steel tool body, which is typically a drill collar. This antenna embodiment is extremely robust, meaning that does not significantly reduce the structural integrity of the tool body in which it is disposed. The antenna embodiment is also relatively wear resistant. The resultant magnetic dipole generated by this antenna is also electrically steerable in inclination angle from a common origin. A variable dipole moment inclination angle combined with independently measured tool rotation orientation during normal drilling allows the antenna to generate a magnetic dipole moment that may be directed at any three dimensional angle and from a common origin point at the centroid of the antenna. The antenna can also be embodied to be more sensitive to resitivity in a particular azimuthal direction.

An electromagnetic antenna for Measurement-While-Drilling (MWD) applications is disclosed. The antenna can include several array elements that can act alone or together in various measurement modes. The antenna elements can be disposed in tool body recesses to be protected from damage. The antenna elements can include a ferrite plate crossed or looped by independent current carrying conductors in two or more directions forming a bi-directional or crossed magnetic dipole. Although disclosed as a MWD system conveyed by a drill string, basic concepts of the system are applicable to other types of borehole conveyance.

Array antenna for measurement-while-drilling

A directional sensor system that incorporates a single axis sensor element that is manipulated to a plurality of orientations. The resulting responses of the sensor element at these locations are combined to obtain a measure of orientation of the system. The system applicable for determining orientation of instrumentation within a well borehole such as measurement-while-drilling, wireline and tubing conveyed borehole instrumentation. The system can be used in other subsurface and surface applications.

Growing community of inventors

Kingwood, TX, United States of America

Jian-Qun Wu