Abstract: A downhole system comprises a main sensor, such as a gamma sensor, and a backup sensor. The backup sensor may be of a different type from the main sensor. In some embodiments the backup sensor is a high reliability sensor that may have a different sensitivity from the main sensor. The system operates both the main and backup sensors and generates calibration data for the backup sensor. If the main sensor fails the calibration data may be applied to process data from the backup sensor to yield an estimate of the data that the main sensor would have yielded if it had remained operational. The calibration data may compensate for temperature variations and/or temporal drift, for example.

Abstract: Arrangements for retaining coiled battery internals in a coiled orientation within a cell casing, in which end caps and/or sleeves are provided with at least one inward-facing protuberance for engaging and securing the coiled battery internals, and means for securing and aligning pouch cell batteries within a sleeve.

Abstract: Arrangements for retaining coiled battery internals in a coiled orientation within a cell casing, in which end caps and/or sleeves are provided with at least one inward-facing protuberance for engaging and securing the coiled battery internals, and means for securing and aligning pouch cell batteries within a sleeve.

Abstract: A downhole system provides a data interface to a first downhole tool such as a steerable rotary tool. The data interface uses a close proximity data connections such as a connection between inductive loops or coils or a direct wired or optical connection. The interface provides data to a second downhole tool in a drill string section adjacent to the first downhole tool. In some embodiments data is passed to a third downhole tool that includes a telemetry transmitter. The third downhole tool may comprise a MWD (measurement while drilling) tool.

Abstract: Method and apparatus for transmitting data to or from a downhole tool while the tool is at or near the surface using a wireless data link. A downhole tool comprising a gap sub having a tubular section with first and second longitudinally spaced-apart electrically-conducting parts that are electrically isolated from each other. An electromagnetic telemetry transmitter is connected to apply a potential difference between the first and second electrically conductive parts. A single-wire bus provides a data connection between one of the first and second electrically conductive parts and a data processor.

Abstract: A device and method for securing a sleeve (for sacrificial wear and/or electrical isolation) inside a conduit. In one embodiment, the retention device sits adjacent one end of the sleeve and comprises a ring having a protuberance or lip extending parallel to and against the end of the sleeve, thus pressing the end of the sleeve against the inner surface of the conduit. This has the advantage, in situations where fluids are flowing through the conduit, of reducing the risk of fluids moving behind the sleeve and collapsing it inwardly.

Abstract: A device and method for retaining a sacrificial wear sleeve on the exterior of an in-pipe device such as an electronics package or probe. In one embodiment, the retention mechanism comprises a ring having a protuberance or lip extending parallel to and against the end of the sleeve, thus pressing the end of the sleeve against the external surface of the device. This has the advantage, in situations where fluids are flowing through the pipe and around the device, of reducing the risk of fluids moving beneath the sleeve and damaging it and/or the underlying device external surface. In another embodiment, the retention mechanism is of unitary construction with the device itself and comprises a protuberance or lip extending parallel to and against the end of the sleeve, thus pressing the end of the sleeve against the external surface of the device.

Abstract: A method and apparatus for downhole data transmission. The method comprising monitoring electrical impedance properties of a downhole formation by applying an electrical signal between a first portion and a second portion of a drill string that are electrically insulated from each other by an insulating portion, selecting a frequency for transmitting data by electromagnetic telemetry based at least in part on the monitored electrical impedance and transmitting the data by encoding the data in a waveform having the selected frequency and applying the waveform between the first portion and the second portion of the drill string.

Abstract: A method and apparatus for downhole data transmission. The method comprising monitoring electrical impedance properties of a downhole formation by applying an electrical signal between a first portion and a second portion of a drill string that are electrically insulated from each other by an insulating portion, selecting a frequency for transmitting data by electromagnetic telemetry based at least in part on the monitored electrical impedance and transmitting the data by encoding the data in a waveform having the selected frequency and applying the waveform between the first portion and the second portion of the drill string.

Abstract: A measurement-while-drilling (MWD) telemetry system comprises a downhole MWD telemetry tool comprising a mud pulse (MP) telemetry unit and an electromagnetic (EM) telemetry unit. The MWD telemetry tool can be configured to transmit data in an EM-only telemetry mode using only the EM telemetry unit, in an MP-only mode using only the MP telemetry unit, or in a concurrent telemetry mode using both the EM and MP telemetry units concurrently. When transmitting data in the concurrent telemetry mode, the telemetry tool can be configured to transmit in a concurrent confirmation mode wherein the same telemetry data is transmitted by each of the EM and MP telemetry units, or in a concurrent shared mode wherein some of the telemetry data is transmitted by the EM telemetry unit, and the rest of the telemetry data is transmitted by the MP telemetry unit. The telemetry tool can be programmed to change its operating telemetry mode in response to a downlink command sent by an operator at surface.

Abstract: Data is communicated from sensors at a downhole location near a drill bit to surface equipment. Communication to the surface equipment may be direct or may pass through a series of nodes. The nodes in some cases are intelligently reconfigured to achieve desired data rates, achieve power management goals, and/or compensate for failed nodes.

Abstract: A downhole system comprises a main sensor, such as a gamma sensor, and a backup sensor. The backup sensor may be of a different type from the main sensor. In some embodiments the backup sensor is a high reliability sensor that may have a different sensitivity from the main sensor. The system operates both the main and backup sensors and generates calibration data for the backup sensor. If the main sensor fails the calibration data may be applied to process data from the backup sensor to yield an estimate of the data that the main sensor would have yielded if it had remained operational. The calibration data may compensate for temperature variations and/or temporal drift, for example.

Abstract: A measurement-while-drilling system is integrated into a mud motor. The measurement-while-drilling system includes sensors which may include inclination and tool face sensors, for example, located near to the drill bit. Data from the near bit sensors is transmitted by way of telemetry, for example, EM telemetry. The mud motor may include a rotating electrical coupling which provides good electrical productivity between an uphole coupling of the mud motor and the rotating mandrel. The EM telemetry transmitter may include an electrically-insulating gap integrated with the mandrel of the mud motor.

Abstract: A data logger comprising a first data store, a second data store and a controller connected to receive output from a temperature sensor indicating a temperature of the first data store. The controller may be configured to write data to the first data store and to switch to writing the data on the second data store if the indicated temperature of the first data store exceeds a first threshold temperature. The first and second data stores may be of different types. Upon the temperature of the first data store transitioning from above the first threshold to below the first threshold, the controller may be configured to copy any data recorded in the second data store to the first data store.

Abstract: A method for sealing a gap sub wherein injected material is used to secure a seal member in a gap. The seal member is positioned in the gap, and the material is then injected into the gap and against the seal member, seating the seal member and securing it in place once the material solidifies. The injected material is preferably electrically non-conductive.

Abstract: A sealing member or gasket for sealing a space between two adjacent surfaces, the sealing member having at least one non-helical circumferential extension or ridge configured for size-on-size or press fit engagement with a corresponding recess in at least one of the surfaces being sealed. The sealing member can be formed by molding followed by insertion between the two adjacent surfaces, or by positioning the surfaces adjacent one another and then injecting or pouring the sealing member material into the space and allowing it to solidify in place.

Abstract: A measurement-while-drilling (MWD) telemetry system comprises a downhole MWD telemetry tool comprising a mud pulse (MP) telemetry unit and an electromagnetic (EM) telemetry unit. The MWD telemetry tool can be configured to transmit data in an EM-only telemetry mode using only the EM telemetry unit, in an MP-only mode using only the MP telemetry unit, or in a concurrent telemetry mode using both the EM and MP telemetry units concurrently. When transmitting data in the concurrent telemetry mode, the telemetry tool can be configured to transmit in a concurrent confirmation mode wherein the same telemetry data is transmitted by each of the EM and MP telemetry units, or in a concurrent shared mode wherein some of the telemetry data is transmitted by the EM telemetry unit, and the rest of the telemetry data is transmitted by the MP telemetry unit. The telemetry tool can be programmed to change its operating telemetry mode in response to a downlink command sent by an operator at surface.

Abstract: A measurement-while-drilling (MWD) telemetry system comprises a downhole MWD telemetry tool comprising a mud pulse (MP) telemetry unit and an electromagnetic (EM) telemetry unit. The MWD telemetry tool can be configured to transmit data in an EM-only telemetry mode using only the EM telemetry unit, in an MP-only mode using only the MP telemetry unit, or in a concurrent telemetry mode using both the EM and MP telemetry units concurrently. When transmitting data in the concurrent telemetry mode, the telemetry tool can be configured to transmit in a concurrent confirmation mode wherein the same telemetry data is transmitted by each of the EM and MP telemetry units, or in a concurrent shared mode wherein some of the telemetry data is transmitted by the EM telemetry unit, and the rest of the telemetry data is transmitted by the MP telemetry unit. The telemetry tool can be programmed to change its operating telemetry mode in response to a downlink command sent by an operator at surface.

Abstract: A measurement-while-drilling (MWD) telemetry system comprises a downhole MWD telemetry tool comprising a mud pulse (MP) telemetry unit and an electromagnetic (EM) telemetry unit. The MWD telemetry tool can be configured to transmit data in an EM-only telemetry mode using only the EM telemetry unit, in an MP-only mode using only the MP telemetry unit, or in a concurrent telemetry mode using both the EM and MP telemetry units concurrently. When transmitting data in the concurrent telemetry mode, the telemetry tool can be configured to transmit in a concurrent confirmation mode wherein the same telemetry data is transmitted by each of the EM and MP telemetry units, or in a concurrent shared mode wherein some of the telemetry data is transmitted by the EM telemetry unit, and the rest of the telemetry data is transmitted by the MP telemetry unit. The telemetry tool can be programmed to change its operating telemetry mode in response to a downlink command sent by an operator at surface.

Abstract: A measurement-while-drilling (MWD) telemetry system comprises a downhole MWD telemetry tool comprising a mud pulse (MP) telemetry unit and an electromagnetic (EM) telemetry unit. The MWD telemetry tool can be configured to transmit data in an EM-only telemetry mode using only the EM telemetry unit, in an MP-only mode using only the MP telemetry unit, or in a concurrent telemetry mode using both the EM and MP telemetry units concurrently. When transmitting data in the concurrent telemetry mode, the telemetry tool can be configured to transmit in a concurrent confirmation mode wherein the same telemetry data is transmitted by each of the EM and MP telemetry units, or in a concurrent shared mode wherein some of the telemetry data is transmitted by the EM telemetry unit, and the rest of the telemetry data is transmitted by the MP telemetry unit. The telemetry tool can be programmed to change its operating telemetry mode in response to a downlink command sent by an operator at surface.