Abstract: An assembly for use in subsurface drilling includes a downhole probe supported by a centralizer. The centralizer comprises a tubular member that extends around the downhole probe. A wall of the centralizer is fluted to provide inward contact points that support the downhole probe and outward contact points that bear against a bore wall of a section of drill string. The downhole probe may be supported for substantially its entire length.

Abstract: An assembly for use in subsurface drilling includes a downhole probe supported by a centralizer. The centralizer comprises a tubular member that extends around the downhole probe. A wall of the centralizer is fluted to provide inward contact points that support the downhole probe and outward contact points that bear against a bore wall of a section of drill string. The downhole probe may be supported for substantially its entire length.

Abstract: A gap sub assembly for electromagnetic telemetry used in downhole drilling. The gap sub comprises a female part comprising a female mating section and a male part comprising a male mating section. The male mating section is matingly received within the female mating section and electrically isolated therefrom. One or more electrically insulating bodies secure the male part axially and torsionally relative to the female part. The electrically insulating bodies also electrically isolate the male part from the female part. The electrically insulating bodies can be installed through apertures in the female part or at least some of the electrically insulating bodies can be installed before the male mating section is inserted into the female mating section. The electrically insulating bodies can be held in place on the male mating section using a retention apparatus such as a ring, a scarf, pods or an adhesive.

Abstract: A downhole system has a plurality of telemetry systems and a control system configured to obtain information from one or more sensors and transmit that information on one or more of the plurality of telemetry systems. The configuration of a controller may be changed so as to change which information is transmitted on a given telemetry system and how the information is to be transmitted on the given telemetry system.

Abstract: A downhole system has a plurality of telemetry systems and a control system configured to obtain information from one or more sensors and transmit that information on one or more of the plurality of telemetry systems. The configuration of a controller may be changed so as to change which information is transmitted on a given telemetry system and how the information is to be transmitted on the given telemetry system.

Abstract: A downhole system has a plurality of telemetry systems and a control system configured to obtain information from one or more sensors and transmit that information on one or more of the plurality of telemetry systems. The configuration of a controller may be changed so as to change which information is transmitted on a given telemetry system and how the information is to be transmitted on the given telemetry system.

Abstract: One or more seals may be provided in a gap sub to prevent the ingress of drilling fluid into an insulating gap between a male member of the gap sub and a female member of the gap sub. A first seal may comprise an internal gap sub seal provided near the tip of the male member of the gap sub. A second seal may comprise an external gap sub seal provided near the tip of the female member of the gap sub. The first and second seals may comprise non-conductive materials. The first and second seals may each comprise one or more O-rings. The first and second seals may comprise one or more lips, protrusions or flanges to engage the male and/or female members of the gap sub for maintaining contact with the male and/or female members during deformation of the gap sub.

Abstract: Methods and apparatus for identifying downhole dynamics in a drilling system are provided. Acceleration-detecting sensors are mounted at multiple locations near to a drill bit, such as at a drill collar. The sensors may be spaced 90° apart along a circumference of the drill collar. The sensors detect acceleration measurements in a plane orthogonal to the drill string's axis of rotation, with respect to a first reference frame that moves with the drill string. The acceleration measurements are received by a processor and processed to determine rotational and revolution positions of the drill string within the wellbore with respect to a static reference frame. Whirl dynamics may, in particular, be determined based on the results in real time.

Abstract: A downhole probe of a drilling rig has a probe sleeve for protecting the downhole probe. The probe sleeve may be made of a metal or a polymer such as polyphenylene sulfide. The probe sleeve may be heat-shrinkable to provide a tight fit between the downhole probe and the probe sleeve. The probe sleeve may include one or more protrusions shaped to engage a centralizer surrounding at least part of the downhole probe. The one or more protrusions may be arranged to prevent rotation of the centralizer relative to the probe sleeve. The probe sleeve may be made using a modified extrusion process and may include reinforcement to add strength to weld-lines along the length of the probe sleeve. The protrusions may also be used as reinforcement.

Abstract: A gap sub assembly for electromagnetic telemetry used in downhole drilling is disclosed. The gap sub comprises a female part comprising a female mating section and a male part comprising a male mating section. The male mating section is matingly received within the female mating section and electrically isolated therefrom. One or more electrically insulating bodies secure the male part axially and torsionally relative to the female part. The electrically insulating bodies also electrically isolate the male part from the female part. The electrically insulating bodies can be installed through apertures in the female part or at least some of the electrically insulating bodies can be installed before the male mating section is inserted into the female mating section. The electrically insulating bodies can be held in place on the male mating section using a retention apparatus such as a ring, a scarf, pods or an adhesive.

Abstract: A downhole system has a plurality of telemetry systems and a control system configured to obtain information from one or more sensors and transmit that information on one or more of the plurality of telemetry systems. The configuration of a controller may be changed so as to change which information is transmitted on a given telemetry system and how the information is to be transmitted on the given telemetry system.

Abstract: Methods and apparatus for identifying downhole dynamics in a drilling system are provided. Acceleration-detecting sensors are mounted at multiple locations near to a drill bit, such as at a drill collar. The sensors may be spaced 90° apart along a circumference of the drill collar. The sensors detect acceleration measurements in a plane orthogonal to the drill string's axis of rotation, with respect to a first reference frame that moves with the drill string. The acceleration measurements are received by a processor and processed to determine rotational and revolution positions of the drill string within the wellbore with respect to a static reference frame. Whirl dynamics may, in particular, be determined based on the results in real time.

Abstract: A gap sub assembly for electromagnetic telemetry used in downhole drilling. The gap sub comprises a female part comprising a female mating section and a male part comprising a male mating section. The male mating section is matingly received within the female mating section and electrically isolated therefrom. One or more electrically insulating bodies secure the male part axially and torsionally relative to the female part. The electrically insulating bodies also electrically isolate the male part from the female part. The electrically insulating bodies can be installed through apertures in the female part or at least some of the electrically insulating bodies can be installed before the male mating section is inserted into the female mating section. The electrically insulating bodies can be held in place on the male mating section using a retention apparatus such as a ring, a scarf, pods or an adhesive.

Abstract: A downhole system has a plurality of telemetry systems and a control system configured to obtain information from one or more sensors and transmit that information on one or more of the plurality of telemetry systems. The configuration of a controller may be changed so as to change which information is transmitted on a given telemetry system and how the information is to be transmitted on the given telemetry system.

Abstract: An assembly for use in subsurface drilling includes a downhole probe supported by a centralizer. The centralizer comprises a tubular member that extends around the downhole probe. A wall of the centralizer is fluted to provide inward contact points that support the downhole probe and outward contact points that bear against a bore wall of a section of drill string. The downhole probe may be supported for substantially its entire length.

Abstract: A fluid pressure pulse generator apparatus for a telemetry tool comprising a stator and a rotor. The stator comprises a stator body and a plurality of radially extending stator projections spaced around the stator body and the spaced stator projections define stator flow channels extending therebetween. The rotor comprises a rotor body and a plurality of radially extending rotor projections spaced around the rotor body. The rotor projections are axially adjacent the stator projections and the rotor is rotatable relative to the stator such that the rotor projections move in and out of fluid communication with the stator flow channels to create fluid pressure pulses in fluid flowing through the stator flow channels. At least one of the rotor projections and at least one of the stator projections has a standard outer diameter. At least one of the rotor projections and/or at least one of the stator projections has a reduced outer diameter.

Abstract: An active downhole antenna located in a borehole receives electromagnetic (EM) telemetry transmissions from sources in adjacent boreholes. The antenna comprises a processor operable do decode and measure signal to noise ratio of received transmissions. Data received at the active antenna is transmitted to surface using a high-speed data communication network. The active antenna may handle data communications from multiple downhole EM telemetry transmitters.

Abstract: A method for establishing downlink telemetry communication to a downhole system involves placing into a drillstring a telemetry transcoder, and advancing the drillstring so the telemetry transcoder is below the surface. The method then transmits downlink EM telemetry signals from surface equipment. These signals are received at the telemetry transcoder which retransmits the signals as mud pulse signals. The mud pulse signals are received at the downhole system.

Abstract: A vehicle for detecting fields relevant to the suitability of a location for EM telemetry reception. The vehicle may include a magnetometer, a voltage monitoring system and position sensors. A wireless transmitter may transmit readings from the meters, monitoring systems and/or sensors to a receiver. The vehicle may include equipment for inserting or removing ground conductors for use in receiving electromagnetic telemetry signals. The vehicle may be driven or may drive itself autonomously. The vehicle may obtain measurements of magnetic field and/or potential differences at spaced apart locations along a path. Data obtained by the vehicle may be analyzed to identify hot spots. After selecting hot spots, the vehicle may be configured to insert ground conductors at selected locations within the hot spots. After installing ground rods, the vehicle may be configured to continuously monitor the area to maintain an optimum configuration of ground conductors.

Abstract: An assembly for use in subsurface drilling includes a downhole probe supported by a centralizer. The centralizer comprises a tubular member that extends around the downhole probe. A wall of the centralizer is fluted to provide inward contact points that support the downhole probe and outward contact points that bear against a bore wall of a section of drill string. The downhole probe may be supported for substantially its entire length.