Abstract:
The embodiments described herein generally relate to a method and apparatus for providing a back up system of Directional and Inclination (D&I) information to be gathered and transmitted in addition to primary D&I sensors currently employed in industry. A downhole probe assembly including primary sensors, back up sensors and a controller is disclosed. The primary sensors comprise primary accelerometers and primary magnetometers configured to gather information relating to each of orthogonal axes X, Y and Z. The back up sensors comprise back up accelerometers configured to gather information relating to each of orthogonal axes X, Y and Z, the back up accelerometers being solid state accelerometers. The controller is in electrical communication with the primary sensors and the back up sensors. The controller is configured to receive and process information from the primary sensors and the back up sensors so that information from the back up accelerometers can be used when one or more of the primary accelerometers fail, which may allow drilling operations to continue despite such failure.
Abstract:
A component mounting apparatus for holding a rigid component in a downhole bore or a downhole collar based application includes a first body including first and second parallel spaced apart component holders disposed in a first common plane and a first support connecting the component holders together. The first and second parallel spaced apart component holders are operable to receive and grip a rigid component between the first and second parallel spaced apart component holders. Various component mounting assemblies and configurations may be realized using the component mounting apparatus described. The component mounting apparatus and various mounting assemblies may be used to mount a printed circuit board in a cylindrical enclosure or to bular housing, for example.
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:
An assembly for receiving telemetry signals from downhole equipment is located at a top end of a drill string above a drill rig floor. The assembly may be configured to receive multiple types of telemetry signals, for example, two or more of electromagnetic telemetry, mud pulse telemetry and drill string acoustic telemetry signals. The assembly may comprise a cap comprising a coupling and an end separated by an electrically-insulating gap region. The end of the cap may be connected to a grounding system for the drill rig.
Abstract:
An electromagnetic telemetry system adjusts telemetry parameters which may include carrier frequency, signal amplitude and/or data encoding protocol to achieve reliable data transmission and to conserve power. In some embodiments, sweep signals transmit a range of carrier frequencies and the parameters are determined in part by analyzing the received sweep signals. In some embodiments, different parameters are selected automatically based on a mode of drilling.
Abstract:
A method for using a downhole probe. The method comprises providing a probe, at least one vertical cross section of the probe having an area of at least pi inches squared. The method further comprises inserting the probe into a bore of a drill collar and passing a drilling fluid through the bore of drill collar at a flow velocity of less than 41 feet per second.
Abstract:
An electromagnetic telemetry signal generating assembly comprises a first section of drill string, a second section of drill string, a gap sub configured to insulate the first section from the second section, and a power source configured to provide a first voltage to a control circuit. The control circuit is configured to drive a second voltage between the sections of drill string. The gap sub provides a gap of at least 12 inches (30 cm). The second voltage may be different than the first voltage.
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 method for regulating an electromagnetic (“EM”) telemetry signal sent from downhole to surface includes determining a value of a controlled parameter of the EM telemetry signal, comparing the value of the controlled parameter to a configuration value, and adjusting the value of the controlled parameter in a first direction towards the configuration value while monitoring a feedback parameter of the EM telemetry signal when the value of the controlled parameter and the configuration value differ. The controlled parameter is one of transmission voltage and transmission current, and the feedback parameter is the other of transmission voltage and transmission current. The value of the controlled parameter ceases to be adjusted in the first direction upon the earlier of either of the following occurring: the value of the controlled parameter substantially equals the configuration value, a value of the feedback parameter meets a feedback parameter cutoff threshold, and a product of the controlled and feedback parameters meets a power cutoff threshold.