Abstract: A downhole tool including a transmitter coil assembly and a receiver coil assembly. The coil assembly includes at least one first coil having a first support member with a first single layer of wire wound therearound. The coil assembly further includes at least one second coil. The second coil includes a second support member having a second single layer of wire wound therearound. The first support member is disposed within the second support member, and the first single layer spaced apart from the second single wire by a distance of D.

Abstract: A logging tool and method for winding a multi-component induction (MCI) antenna is presented. The method eliminates unwanted dipole signals that are created by the voltage drop that takes place in the transmitter. The antenna is made of at least two parts physically separated, one on each side of the mandrel. The winding method is performed in a way that creates at least four windings arranged to eliminate dipole signals attributable to an asymmetric voltage distribution. The midpoint of the conductive wire that for is the antenna windings may be electrically attached to the tool body. This method is suitable for the winding of the cross-components X and Y of the MCI coil arrays.

Abstract: A system and method for reducing borehole effects in a borehole within a subterranean formation is disclosed. The apparatus includes a fluid excluder, which includes a sleeve body and a sleeve opening defined by the sleeve body. The sleeve may be sized to fit around an induction tool. The sleeve body may include a fluid passageway therethrough, which may divert drilling fluids when the apparatus is deployed downhole. The apparatus may further include an electrode disposed within the fluid passageway for reducing the electrical current in the drilling fluid and thereby improve the readings obtained by logging devices.

Abstract: A logging tool and method for winding a multi-component induction (MCI) antenna is presented. The method eliminates unwanted dipole signals that are created by the voltage drop that takes place in the transmitter. The antenna is made of at least two parts physically separated, one on each side of the mandrel. The winding method is performed in a way that creates at least four windings arranged to eliminate dipole signals attributable to an asymmetric voltage distribution. The midpoint of the conductive wire that for is the antenna windings may be electrically attached to the tool body. This method is suitable for the winding of the cross-components X and Y of the MCI coil arrays.

Abstract: A downhole tool including a transmitter coil assembly and a receiver coil assembly. The coil assembly includes at least one first coil having a first support member with a first single layer of wire wound therearound. The coil assembly further includes at least one second coil. The second coil includes a second support member having a second single layer of wire wound therearound. The first support member is disposed within the second support member, and the first single layer spaced apart from the second single wire by a distance of D.

Abstract: An apparatus and method for performing high transverse resolution voltage measurements in downhole logging tools utilized to determine the resistivity of an adjacent portion of a borehole wall. Two current electrodes 508 and 509 are energized by an excitation source to create an oscillatory electric field in a borehole wall. The voltage drop from each voltage electrode in a row of laterally spaced voltage electrodes 604 is measured relative to a shared voltage electrode 606 longitudinally spaced from the row of electrodes. The differential voltage is used in combination with a measured current flow to determine a resistivity value for the borehole. A second row of laterally spaced voltage electrodes 608 having electrodes laterally offset from the electrodes of the first row is included to provide high transverse resolution. A common mode voltage at the shared voltage electrodes is measured and utilized to minimize the resistivity measurement error.

Abstract: A device is provided, the device comprising a downhole tool comprising a wire comprising at least one strand comprising a low thermal expansion material. The low thermal expansion material may have a low electrical resistance material disposed thereon.

Abstract: An apparatus and method for performing high transverse resolution voltage measurements in downhole logging tools utilized to determine the resistivity of an adjacent portion of a borehole wall Two current electrodes 508 and 509 are energized by an excitation source to create an oscillatory electric field in a borehole wall The voltage drop from each voltage electrode in a row of laterally spaced voltage electrodes 604 is measured relative to a shared voltage electrode 606 longitudinally spaced from the row of electrodes The differential voltage is used in combination with a measured current flow to determine a resistivity value for the borehole A second row of laterally spaced voltage electrodes 608 having electrodes laterally offset from the electrodes of the first row is included to provide high transverse resolution A common mode voltage at the shared voltage electrodes is measured and utilized to minimize the resistivity measurement error

Abstract: An orientation sensing apparatus includes a rotatable first member, an orientation sensor device fixed with the first member for generating orientation data relating to an orientation sensor device orientation, and a rotation sensor device for generating rotation data relating to rotation of the first member. A method for determining an orientation includes assembling a set of sensor data including the orientation data and rotation data and processing the set of sensor data to generate a set of corrected orientation data. The set of corrected orientation data includes the orientation data which has been corrected using the rotation data to reduce the effects of rotation of the first member and misalignment of the gravity sensor device. One or more sets of corrected orientation data may be processed to determine an inclination orientation of the first member or a toolface orientation of a second member which is connected with the first member.

Abstract: An orientation sensing apparatus includes a rotatable first member, an orientation sensor device fixed with the first member for generating orientation data relating to an orientation sensor device orientation, and a rotation sensor device for generating rotation data relating to rotation of the first member. A method for determining an orientation includes assembling a set of sensor data including the orientation data and rotation data and processing the set of sensor data to generate a set of corrected orientation data. The set of corrected orientation data includes the orientation data which has been corrected using the rotation data to reduce the effects of rotation of the first member and misalignment of the gravity sensor device. One or more sets of corrected orientation data may be processed to determine an inclination orientation of the first member or a toolface orientation of a second member which is connected with the first member.

Abstract: In some embodiments, a device includes a downhole tool comprising a wire comprising at least one strand comprising a low thermal expansion material. The low thermal expansion material may have a low electrical resistance material disposed thereon.

Abstract: A telemetry system and method for communicating information axially along a drill string comprised of a drive train supported within a housing. The system includes an axial conducting loop formed by the drill string for conducting an axial electrical signal embodying the information between a first axial position and a second axial position in the drill string, which axial conducting loop extends between the first and second axial positions. A transmitter transmits information to the axial conducting loop. The drive train includes a downhole end which extends from and is located below the housing. At least one of the first and second axial positions is located in the downhole end. The method includes the step of conducting the axial electrical signal between the first and second axial positions through the axial conducting loop which extends between the first and second axial positions.

Abstract: The present invention is directed to a logging tool induction coil form having a coating layer, which is easy to form to tight tolerances, bonded to at least a portion of the outer surface of the ceramic hollow cylindrical core. A plurality of parallel circumferential grooves are machined into the coating layer. Since the coating material is easy to machine, the parallel circumferential grooves can be machined to the tight tolerances needed in logging applications at a fraction of the time and cost of machining ceramic-only forms.

Abstract: A drilling shaft deflection assembly for a drilling direction control device of the type comprising a rotatable drilling shaft and a housing for supporting a length of the drilling shaft for rotation therein. The deflection assembly is contained within the housing and is axially located between a first support location and a second support location for bending the drilling shaft between the first support location and the second support location. The deflection assembly includes a deflection mechanism for imparting lateral movement to the drilling shaft to bend the drilling shaft, a deflection actuator for actuating the deflection mechanism in response to longitudinal movement of the deflection actuator, and a deflection linkage mechanism between the deflection mechanism and the deflection actuator for converting longitudinal movement of the deflection actuator to lateral movement of the drilling shaft.

Abstract: A telemetry system and method for communicating information axially along a drill string comprised of a drive train supported within a housing. The system includes an axial conducting loop formed by the drill string for conducting an axial electrical signal embodying the information between a first axial position and a second axial position in the drill string, which axial conducting loop extends between the first and second axial positions. A transmitter transmits information to the axial conducting loop. The drive train includes a downhole end which extends from and is located below the housing. At least one of the first and second axial positions is located in the downhole end. The method includes the step of conducting the axial electrical signal between the first and second axial positions through the axial conducting loop which extends between the first and second axial positions.

Abstract: A drilling shaft deflection assembly for a drilling direction control device of the type comprising a rotatable drilling shaft and a housing for supporting a length of the drilling shaft for rotation therein. The deflection assembly is contained within the housing and is axially located between a first support location and a second support location for bending the drilling shaft between the first support location and the second support location. The deflection assembly includes a deflection mechanism for imparting lateral movement to the drilling shaft to bend the drilling shaft, a deflection actuator for actuating the deflection mechanism in response to longitudinal movement of the deflection actuator, and a deflection linkage mechanism between the deflection mechanism and the deflection actuator for converting longitudinal movement of the deflection actuator to lateral movement of the drilling shaft.

Abstract: The invention relates to a data transmission or telemetry system and a method for communicating information axially along a drill string. The method includes the step of conducting an axial electrical signal embodying the information between a first axial position in the drill string and a second axial position in the drill string through an axial conducting loop formed by the drill string, which axial conducting loop extends between the first and second axial positions. The system includes the axial conducting loop for conducting the axial electrical signal embodying the information between the first and second axial positions and a transmitter for transmitting the information to the axial conducting loop. The system further preferably includes a receiver for receiving the information from the axial conducting loop. Finally, the portion of the drill string forming the axial conducting loop is preferably comprised of a downhole motor drilling assembly.