SYSTEM AND METHOD FOR MANAGING BATTERIES FOR USE IN A DOWNHOLE DRILLING APPLICATION

The present disclosure is directed at methods, systems, and techniques for managing batteries for use in a downhole drilling application. The system includes a power bus, pairs of battery terminals for connecting to batteries, switching circuitry that connects and disconnects the batteries to the power bus, data collection circuitry that obtains battery parameters obtained during system operation, and a controller that controls the switching circuitry and receives the battery parameters. A control line connects the controller to the switching circuitry and a data line connects the controller to the data collection circuitry, with the control and data lines being distinct such that control and data signals are not multiplexed with each other. 1. A battery management system for use in a downhole drilling application , the battery management system comprising:(a) a power bus;(b) pairs of battery terminals, wherein each of the battery terminals is for connecting to a battery;(c) switching circuitry operable to electrically connect the power bus to and to disconnect the power bus from any one or more of the pairs of battery terminals electrically connected in parallel;(d) data collection circuitry operable to obtain battery parameters of batteries connected to the pairs of battery terminals;(e) a controller operable to control the switching circuitry and to receive the battery parameters from the data collection circuitry; and(f) a control line communicatively connecting the controller to the switching circuitry and a data line, distinct from the control line, communicatively connecting the controller to the data collection circuitry.2. The system of wherein there are multiple control lines claim 1 , and the controller is configured to use each of the control lines to control whether only one of the pairs of battery terminals is connected to or disconnected from the power bus.3. The system of wherein there are multiple data lines claim 1 , and the controller is ...

INTEGRATED DOWNHOLE SYSTEM WITH PLURAL TELEMETRY SUBSYSTEMS

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. 1. A downhole system comprising:a plurality of telemetry subsystems,a control system comprising a plurality of telemetry controllers, each telemetry controller associated and in communication with at least one telemetry subsystem of the plurality of telemetry subsystems,a bus, each telemetry controller of the plurality of telemetry controllers being in communication with each other telemetry controller of the plurality of telemetry controllers via the bus, andone or more sensors in communication with the plurality of telemetry controllers,wherein:a first telemetry controller of the plurality of telemetry controllers is associated with a first telemetry subsystem of the plurality of telemetry subsystems and is operable to obtain first sensor information from a first set of the one or more sensors and to transmit the first sensor information on the first telemetry subsystem; anda second telemetry controller of the plurality of telemetry controllers is associated with a second telemetry subsystem of the plurality of telemetry subsystems and is operable independently of the first telemetry controller to obtain second sensor information from a second set of the one or more sensors and to transmit the second sensor information on the second telemetry subsystem.2. A downhole system according to wherein the control system is configured to provide a splitting mode wherein the control system is operable to obtain a data unit for transmission claim 1 , transmit a first part of the data unit using a first one of the telemetry subsystems and transmit a second part of ...

DETECTION OF DOWNHOLE DATA TELEMETRY SIGNALS

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. 1. A signal receiving assembly suitable for transmitting and/or receiving telemetry data to/from downhole equipment , the signal receiving assembly comprising:a first section and a second section, wherein the first section is configured to be electrically coupled into a drill string and the second section is electrically insulated from the first section;a blow out preventer; anda signal detector, wherein the signal detector is electrically coupled to the second section, the first section, and the blow out preventer, and wherein the signal detector is configured to measure a difference in voltage between the second section and the first section and a difference in voltage between the second section and the blow out preventer.2. A signal receiving assembly according to wherein the signal receiving assembly is located above ground.3. A signal receiving assembly according to wherein the first section comprises a coupling configured for coupling the first section to a drill string.4. A signal receiving assembly according to wherein the coupling is configured for coupling the first section to a top end of the drill string.5. A signal receiving assembly according to wherein the first section comprises a coupling configured for coupling the first section to a kelly.6. A signal receiving assembly according to wherein the coupling is configured for coupling the first section to a top end of the kelly.7. A signal receiving assembly according to wherein the ...

Automated drilling methods and systems using real-time analysis of drill string dynamics

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.

PINNED ELECTROMAGNETIC TELEMETRY GAP SUB ASSEMBLY

A gap sub comprises a female member comprising a first and second plurality of apertures, and a male member comprising a first and second plurality of cavities. A plurality of non-conductive pins may be inserted through the second plurality of apertures and the second plurality of cavities, thereby locking the relative positions of the female and male members. A plurality of conductive pins may be inserted through the first plurality of apertures and the first plurality of cavities such that there are no electrical connections between the conductive pins and the male member. A dielectric material may be inserted between the male member and the conductive pins. 1. A gap sub comprising:a female member;a male member coupled to the female member, the male member at least partially inserted into a bore of the female member; anda plurality of electrically-conductive pins; each of the plurality of electrically-conductive pins is oriented radially relative to the gap sub and extends from a corresponding one of a first plurality of apertures in the female member into a corresponding one of a first plurality of cavities in the male member; and', 'each of the plurality of electrically-conductive pins is electrically-insulated from at least one of the female member and the male member., 'wherein2. A gap sub according to wherein each of the plurality of electrically-conductive pins is electrically-insulated from the male member.3. A gap sub according to comprising a dielectric material filling a space between each of the plurality of electrically-conductive pins and an inner surface of a corresponding one of the first plurality of cavities.4. A gap sub according to wherein each of the electrically-conductive pins is coupled to a corresponding one of the first plurality of apertures by a threaded connection.5. A gap sub according to wherein each of the electrically-conductive pins is coupled to a corresponding one of the first plurality of apertures by a press fit.6. A gap sub ...

Gap assembly for em data telemetry

A gap sub has electrically-conductive parts held together by electrical insulators which engage in channels formed in the parts. The electrical insulators hold the parts in a spaced-apart electrically-insulated relationship. In some embodiments, the electrical insulators are removable to allow separation of the parts. An insulating oil or other fluid may fill the gap.

Downhole tool with plural data stores

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.

CENTRALIZER FOR DOWNHOLE PROBES

An assembly for use in subsurface drilling includes a downhole 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. 1. A centralizer for use in subsurface drilling , the centralizer comprising:an elongated tubular member having a wall formed to provide a cross-section that provides first outwardly-convex and inwardly-concave lobes, the first lobes arranged to contact a bore wall of a bore in a section of drill string at a plurality of spots spaced apart around a circumference of the bore wall; anda plurality of inwardly-projecting portions, each of the plurality of inwardly-projecting portions arranged between two adjacent ones of the plurality of first lobes.2. A centralizer according to wherein the inwardly-projecting portions comprise inwardly-projecting lobes that are inwardly-convex and outwardly-concave.3. A centralizer according to wherein the inwardly-projecting lobes are minor symmetrical about an axis passing through a longitudinal centerline of the centralizer.4. A centralizer according to wherein a thickness of the wall is substantially uniform.5. A centralizer according to wherein the wall has a thickness in the range of about 0.1 to 0.3 inches.6. A centralizer according to wherein the wall has a thickness of 0.15 to 0.25 inches.7. A centralizer according to wherein claim 2 , in cross-section the centralizer has 4-fold rotational symmetry.8. A centralizer according to wherein the cross-section provides four first lobes.9. A centralizer according to wherein the cross-section provides two to eight first lobes.10. A centralizer according to wherein each of the plurality of first lobes is minor symmetrical about an axis passing ...

Optimizing downhole data communication with at bit sensors and nodes

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.

AXIALLY-SUPPORTED DOWNHOLE PROBES

An assembly for use in subsurface drilling includes a downhole probe supported by a locking mechanism with a bore of a drill string section. The probe comprises a first spider and a second spider at the uphole and downhole sections of the probe. The locking mechanism secures the probes in the bore against axial and rotational movement relative the drill string section. 1. A downhole assembly comprising:a drill string section having a bore extending longitudinally through the drill string section;a downhole probe located in the bore of the section; the probe supported in the bore by first and second spiders spaced apart longitudinally within the bore, at least one of the first and second spiders abutting a landing step in a wall of the bore.2. A downhole assembly according to wherein the first spider is coupled to an uphole end of the probe and the second spider is coupled to a downhole end of the probe; and at least one of the first and second spiders is coupled non-rotationally to the probe and to the drill string section.3. A downhole assembly according to wherein the landing step is adjacent the uphole end of the probe and the first spider is configured to engage the landing step.4. A downhole assembly according to wherein the locking mechanism comprises at least one key member coupled to the probe away from the landing claim 3 , the at least one key member engages a corresponding at least one key channel in the section.5. A downhole assembly according to wherein the at least one key member is connected to the second spider.6. A downhole assembly according to wherein the section comprises a landing adjacent the downhole end of the probe and the second spider is configured to engage the landing.7. A downhole assembly according to wherein the landing comprises a step in the bore of the section.8. A downhole assembly according to wherein the locking mechanism comprises at least one key member coupled to the probe away from the landing claim 7 , the at least one key ...

MUD MOTOR WITH INTEGRATED ABRASION-RESISTANT STRUCTURE

A housing for a mud motor is disclosed. The housing comprises a female member comprising a female mating section and a male member comprising a male mating section and a housing section. The male mating section is matingly received within the female mating section. The collar is positioned on the housing section. The collar is made up of a framework with a plurality of discrete bodies spaced about the framework and a portion of each of the discrete bodies protrudes above the framework. 1. A housing for a downhole component , the housing comprising a collar having a pair of longitudinal ends spaced apart from each other and a bore therethrough , the collar comprising:(a) a framework; and(b) a plurality of discrete bodies spaced about the framework, a portion of each of the plurality of discrete bodies protruding above a surface of the framework;wherein the framework and the plurality of discrete bodies extend between the longitudinal ends of the collar.2. A housing as claimed in wherein the framework comprises a wear-resistant material.3. A housing as claimed in claim 2 , wherein the framework comprises a metal or metal alloy.4. A housing as claimed in any one of to claim 2 , wherein the plurality of discrete bodies are spheres.5. A housing as claimed in any one of to wherein the plurality of discrete bodies comprise a wear-resistant material.6. A housing as claimed in wherein the plurality of discrete bodies comprise carbide.7. A housing as claimed in any one of to claim 5 , wherein the framework comprises a plurality of rings with opposed side faces and at least some of the discrete bodies are engaged between side faces of adjacent ones of the rings.8. A housing as claimed in wherein at least one of the one or more than one ring with opposed side faces is tapered in thickness such that the outer part claim 7 , furthest from the bore claim 7 , is thicker than the inner part claim 7 , closest to the bore.9. A housing as claimed in claim 7 , wherein the framework ...

Mud motor with integrated mwd system

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.

DOWNHOLE POCKET ELECTRONICS

An assembly for use in subsurface drilling includes a drill collar section having a bore extending longitudinally through an inner surface of the drill collar section. A pocket is formed in a section of the inner surface of the drill collar section. A holster is located in the pocket and a sleeve is snuggly fitted inside the bore in order to secure the holster inside the pocket. The sleeve may be sealed to the drill collar section for example by seals such as O-rings such that the holster is sealed from the bore. O-rings may be located on one or both of the inside of the inner surface of the collar or on the outside of the sleeve. 1. A downhole assembly comprising:a drill collar section having a longitudinally-extending through bore and at least one of a box coupling and a pin coupling;a pocket opening into the bore, the pocket formed in an inner surface of the drill collar section;an electronics package located in the pocket; anda sleeve snugly fitted inside the bore;wherein the sleeve secures the electronics package in the pocket.2. A downhole assembly according to wherein the drill collar section comprises a box coupling and the sleeve is insertable into the bore through the box coupling.3. A downhole assembly according to wherein the bore includes an abutment surface that engages a surface of the sleeve to limit travel of the sleeve into the bore.4. A downhole assembly according to wherein the abutment surface comprises a shoulder between a first portion of the bore having a larger diameter and a second portion of the bore having a smaller diameter.5. A downhole assembly according to wherein an outside of the sleeve comprises a step between a larger-diameter portion of the sleeve and a smaller-diameter portion of the sleeve and the step of the sleeve engages the abutment surface of the bore when the sleeve is fully inserted into the bore.6. A downhole assembly according to wherein the electronics package has a shape complementary to a shape of the pocket.7. A ...

TELEMETRY SYSTEMS WITH COMPENSATION FOR SIGNAL DEGRADATION AND RELATED METHODS

This invention comprises systems, methods and apparatus for mud pulse telemetry involving sending benchmark pulses with known characteristics (such as amplitude or duration) from the surface to the BHA, measuring those characteristics at the BHA, using those measurements to predict the likely attenuation of downhole-to-surface mud pulse transmissions, and adjusting those transmissions to compensate for high attenuation or to obtain energy savings (or transmission rate increases) during low-attenuation conditions. Further refinements on these systems and methods, particularly concerning the use of signal-to-noise ratio measurements at the surface to more efficiently predict attenuation, are also disclosed. 1. A mud pulse telemetry system comprising:a first pulse sensor in fluid communication with a first pulse generator by way of a drillstring; anda second pulse generator in fluid communication with a second pulse sensor by way of the drillstring;wherein:the first pulse generator is configured to transmit a benchmark pulse with a known characteristic to the first pulse sensor, the benchmark pulse propagating in a first direction along the drillstring;the first pulse sensor is configured to measure the known characteristic of the received benchmark pulse;a first processor is configured to generate one or more telemetry parameters based at least in part on the known characteristic of the received benchmark pulse; andthe first processor is configured to control and/or cause a second processor to control the second pulse generator to transmit to the second pulse sensor a set of one or more mud pulses according to the one or more telemetry parameters, the set of one or more mud pulsed propagating along the drillstring in a second direction opposite to the first direction.2. A mud pulse telemetry system according to wherein:the first processor is provided by surface equipment in communication with the first pulse sensor and the second pulse generator.3. A mud pulse ...

METHODS AND APPARATUS FOR GENERATING ELECTROMAGNETIC TELEMETRY SIGNALS

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. 1. Apparatus for use in EM telemetry , the apparatus comprising a gap sub comprising:first and second electrically conductive members the first and second electrically conductive members mechanically connected to one another and electrically insulated from one another;a pin coupling on the first electrically conductive member;a box coupling on the second electrically conductive member;a bore extending longitudinally through the gap sub from the pin coupling to the box coupling; and,an electromagnetic telemetry signal generator connected to apply an electrical signal between the first and second electrically conductive members;wherein the electromagnetic telemetry signal generator comprises a control circuit, and a power source wherein:the power source is configured to provide a first voltage to the control circuit;the control circuit is configured to drive a second voltage greater than the first voltage between the first and second electrically conductive members.2. Apparatus according to wherein a distance between electrically conductive parts of the first and second electrically conducting members exposed on an outer surface of the gap sub is at least 8 inches (20 cm).3. Apparatus according to wherein the electromagnetic telemetry signal generator is housed in a probe comprising a housing having a rod extending axially from one end claim 1 , the rod extending through the bore of the gap sub claim 1 , the rod providing at least part of the electrical connection between ...

DOWNHOLE TELEMETRY

A telemetry system with a plurality of controllers and telemetry systems, where the controllers are 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. 1. A telemetry system comprising:plurality of telemetry subsystems,a control system comprising a plurality of telemetry controllers, each telemetry controller associated and in communication with at least one telemetry subsystem of the plurality of telemetry subsystems,a bus, each telemetry controller of the plurality of telemetry controllers being in communication with each other telemetry controller of the plurality of telemetry controllers via the bus, andone or more sensors in communication with the plurality of telemetry controllers,wherein:a first telemetry controller of the plurality of telemetry controllers is configured to obtain first part sensor information from a first set of the one or more sensors and to transmit the first part sensor information on a first telemetry subsystem of the plurality of telemetry subsystems, anda second telemetry controller of the plurality of telemetry controllers is configured to obtain second sensor part information from a second set of the one or more sensors and to transmit the second sensor part information on a second telemetry subsystem of the plurality of telemetry subsystems.2. A telemetry system according to wherein the first telemetry subsystem comprises an EM telemetry subsystem.3. A telemetry system according to wherein the control system is configured to monitor to detect that EM telemetry is ineffective or undesired and to automatically stop using the first telemetry subsystem and to reallocate data from the first part sensor information to the second part sensor information in response to detecting EM telemetry is ineffective or undesired.4. A ...

Method and apparatus for placing receiver electrodes for em telemetry transmissions

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.

Centralizer for downhole probes

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.

Downhole probe assembly with bluetooth device

The embodiments described herein generally relate a downhole probe assembly incorporating a Bluetooth device for wirelessly transmitting electrical information between the downhole probe assembly and a surface electronic interface such as a computer when the probe assembly is above ground. The downhole probe assembly includes sensors for sensing downhole conditions; a controller in electrical communication with the sensors and configured to receive and process information from the sensors; a housing enclosing the one or more than one sensor and the controller; the Bluetooth device in electrical communication with the controller; and an end cap assembly fitted at one end of the housing. The end cap assembly partially surrounds the Bluetooth device and is configured for transmission of the electrical information therethrough. Also described is an end cap assembly for fitting to one end of a downhole probe assembly including a transmission module mated with and electrically connected to the Bluetooth device. The end cap assembly includes an end cap having an end cap mating section configured to mate with a mating section of the transmission module to form a chamber enclosing the Bluetooth device between the transmission module and the end cap. A known downhole probe assembly can be retrofitted with the Bluetooth device and end cap subassembly. The end cap subassembly is configured and adapted to promote signal transmission between the Bluetooth device and a surface computer or other electronic interface.

TRANSMITTING DATA ACROSS ELECTRICALLY INSULATING GAPS IN A DRILL STRING

A range of apparatus and methods for providing local and long range data telemetry within a wellbore is described. These apparatus and methods may be combined in a wide variety of ways. In some embodiments data is transmitted across a gap in a drill string using signals of a higher frequency for which an electrical impedance of the gap or of a filter connected across the gap is low. Low-frequency EM telemetry signals may be applied across the gap. The gap and any filter connected across the gap present a high impedance to the low-frequency EM telemetry signals. The described technology may be applied for transferring sensor readings between downhole electrical packages. In some embodiments sensors are electrically connected across electrically insulating gaps in the drill string. 1. A gap sub assembly comprising:an electrically conductive uphole portion and an electrically conductive downhole portion separated by an electrically-insulating gap;an EM telemetry signal generator connected to apply a low frequency EM telemetry signal between the uphole portion and the downhole portion; anda data signal generator connected to drive a higher-frequency data signal across the gap, the data signal having frequencies higher than the EM telemetry signal at which the gap presents a reduced impedance.2. The gap sub assembly according to comprising an electrical high-pass or bandpass filter electrically connected across the gap.3. The gap sub assembly according to wherein the filter comprises one or more capacitors connected between the electrically conductive uphole portion and the electrically conductive downhole portion.4. The gap sub assembly according to wherein the filter comprises an inductive coupling.5. The gap sub assembly according to comprising a sensor circuit connected in series with the filter.6. The gap sub assembly according to wherein the EM telemetry signal generator is located in a probe in a bore of the gap sub assembly claim 1 , the probe having terminals in ...

OPTIMIZING ELECTROMAGNETIC TELEMETRY TRANSMISSIONS

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. 1. A method for downhole electromagnetic (EM) telemetry in a downhole drilling operation , the method comprising the steps of:determining a mode of the drilling operation;sending a set of EM sweep signals from a downhole EM telemetry system located at a downhole location to an uphole system located at a surface location, each of the EM sweep signals having a different frequency;determining whether each of the EM sweep signals is received at the uphole system and, for the EM sweep signals received, measuring parameters of the received EM sweep signals, the parameters comprising at least one of signal strength and signal-to-noise-ratio;based at least in part on: the mode of drilling operation, the EM sweep signals received, and the parameters measured, determining a protocol for downhole data transmission, the protocol specifying protocol parameters including one or more of signal frequency, signal amplitude, and data encoding scheme; andconfiguring the downhole EM telemetry system to transmit data to the uphole system using the protocol.2. A method according to wherein: the data encoding scheme comprises a number of cycles of EM signals to use for encoding symbols for transmission; anddetermining the protocol comprises setting the number of cycles to be used for encoding signals for transmission.3. A method according to wherein each mode of the drilling operation is assigned a pre-set protocol.4. A method according to wherein the protocol is determined based at least in part on one or more of a desired data ...

DOWNHOLE SYSTEM WITH INTEGRATED BACKUP SENSORS

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. 1. A sensor system for use in a downhole system , the sensor system comprising:a first sensor operable to sense an environmental property;a second sensor operable to sense the environmental property; and receive, from the first sensor, a first calibration sensor reading acquired at a first time;', 'receive, from the second sensor, a second calibration sensor reading acquired at substantially the first time;', 'determine, based on the first and second calibration sensor readings, calibration information for the second sensor;', 'receive, from the second sensor, a backup sensor reading acquired at a second time subsequent to the first time;', 'determine, based on the calibration information and the backup sensor reading, an estimated replacement sensor reading estimating a sensor reading by the first sensor at the second time., 'a controller in communication with the first and second sensors, the controller configured to2. A sensor system according to claim 1 , wherein the controller is configured to calibrate the second sensor to estimate the output of the first sensor so that the backup sensor reading comprises the estimated replacement sensor reading.3. A sensor system according to claim 1 , wherein:the controller is configured to receive, from the first sensor, a plurality of sensor ...

Methods and apparatus for downhole probes

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.

Integrated downhole system with plural telemetry subsystems

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.

Fluid pressure pulse generator and method of using same

A fluid pressure pulse generator comprising a stator and rotor that can be used in measurement while drilling using mud pulse or pressure pulse telemetry is disclosed. The stator comprises a stator body with a circular opening therethrough and the rotor comprises a circular rotor body rotatably received in the circular opening of the stator body. One of the stator body or the rotor body comprises one or more than one fluid opening for flow of fluid therethrough and the other of the stator body or the rotor body comprises one or more than one full flow chamber. The rotor is rotatable between a full flow configuration whereby the full flow chamber and the fluid opening align so that fluid flows from the full flow chamber through the fluid opening, and a reduced flow configuration whereby the full flow chamber and the fluid opening are not aligned. The flow of fluid through the fluid opening in the reduced flow configuration is less than the flow of fluid through the fluid opening in the full flow configuration thereby generating a fluid pressure pulse.

Detection of downhole data telemetry signals

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.

Measurement while drilling fluid pressure pulse generator

A coupling key for fixedly coupling a driveshaft to a rotating component of a measurement while drilling telemetry apparatus comprises a key body and at least one zero backlash ring. The key body has dimensions selected to fit within a keyhole of a driveshaft and a receptacle of a rotating component, with a gap that is large enough that the key body can be freely inserted into the keyhole and receptacle and small enough that the coupling body can couple the driveshaft to the rotating component in a rotational direction. The least one zero backlash ring extends around the key body and protrudes from surfaces of the key body and into the gap such that an interference fit is established between the coupling key, the keyhole, and the receptacle when the coupling key is coupling the driveshaft and rotating component together.

Electromagnetic communications system and method for a drilling operation

A wireless communications system for a downhole drilling operation comprises surface communications equipment and a downhole telemetry tool. The surface communications equipment comprises a surface EM communications module with an EM downlink transmitter configured to transmit an EM downlink transmission at a frequency between 0.01 Hz and 0.1 Hz. The downhole telemetry tool is mountable to a drill string and has a downhole electromagnetic (EM) communications unit with an EM downlink receiver configured to receive the EM downlink transmission. The downhole EM communications unit can further comprise an EM uplink transmitter configured to transmit an EM uplink transmission at a frequency greater than 0.5 Hz, in which case the surface EM communications module further comprises an EM uplink receiver configured to receive the EM uplink transmission. More particularly, the downhole EM uplink transmitter can be configured to transmit the EM uplink transmission at a frequency that is at least ten times higher than the EM downlink transmission frequency.

DRILL COLLAR WITH INTEGRATED PROBE CENTRALIZER

An assembly for use in subsurface drilling includes a downhole probe supported in a drill string section by centralizing features that are integral with the drill string section. A bore wall of the drill string section is fluted to provide inward contact points that support the downhole probe. The downhole probe may be supported for substantially its entire length. A vibration damping and/or electrically insulating material may optionally be provided between the downhole probe and the drill string section. 1. A downhole assembly comprising:a drill string section having a bore extending longitudinally through the drill string section and a downhole probe located in the bore of the sectionwherein the drill string section comprises centralizing features extending inwardly from a wall of the bore, the centralizing features supporting the downhole probe in the bore and the centralizing features are arranged to provide passages for the flow of drilling fluid around an outside of the downhole probe between the centralizing features.2. A downhole assembly according to wherein the section comprises a plurality of components coupled together.3. A downhole assembly according to wherein the section comprises a plurality of collars coupled together by threaded couplings.4. A downhole assembly according to any one of to wherein the section has a cylindrical outer wall.5. A downhole assembly according to any one of to wherein the centralizing features are integral with the section.6. A downhole assembly according to any one of to wherein the probe has a fixed rotational orientation relative to the section.7. A downhole assembly according to any one of to wherein the centralizing features comprise a plurality of ridges circumferentially spaced apart around a periphery of the bore and extending longitudinally within the bore.8. A downhole assembly according to wherein the probe comprises projecting features that project to engage between the plurality of ridges.9. A downhole ...

Optimizing electromagnetic telemetry transmissions

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.

Mud pulse telemetry apparatus with a pressure transducer and method of operating same

A pressure measurement apparatus for a downhole measurement-while-drilling tool comprises a feed through connector and a pressure transducer. The feed through connector comprises a body with a first end and an opposite second end, at least one electrical interconnection extending axially through the body and out of the first and second ends, and a pressure transducer receptacle in the first end and a communications bore extending from the receptacle to the second end. The pressure transducer is seated in the receptacle such that a pressure at the first end can be measured, and comprises at least one electrical contact that extends from the pressure transducer through the communication bore and out of the second end. The pressure transducer can take pressure measurements used to predict wear of a primary seal in a motor subassembly of the tool, detect a pressure-related battery failure event, and control operation of a dual pulse height fluid pressure pulse generator.

Rotary locking sub for angular alignment of downhole sensors with high side in directional drilling

Adjustment of the angle of a bent sub or other steering feature in a drill string relative to a reference angle of a downhole sensor is facilitated by a rotatable coupling between the bent sub and the sensor. The rotatable coupling may be rotated to align the high side with a reference indicium and locked at the set angle. Rows of ceramic balls retained in circumferential channels may be provided to permit rotation while carrying tensile and compressional forces. Calibration of the sensor is facilitated and opportunities for certain measurement errors are eliminated. An embodiment provides a mechanism for locking the rotatable coupling at a desired angle. The embodiment comprises a ring with teeth that engage a downhole portion of the coupling and depressions that engage an uphole portion of the coupling.

DOWNHOLE PROBES AND SYSTEMS

Disclosed are downhole probes in which electrical interconnections between different modules are achieved without wiring harnesses. Modules may be coupled to one another and/or to bulkheads in the probe my couplings that provide substantially rigid couplings. The couplings may be configured to connect together only in one orientation. Electrical connectors may be fixed relative to components of the couplings so that the electrical connectors are automatically aligned for connection by the couplings. 1. A downhole probe comprising:an elongated housing andfirst and second modules arranged in a row and fixed relative to one another within the housing, each of the first and second modules comprising one or more electrical components and being electrically connected to the other one of the first and second modules by way of an electrical connection; a first electrical connector attached to the first module and electrically connected to one or more of the electrical components of the first module by one or more immobilized first electrical conductors; and', 'a second electrical connector attached to the second module and electrically connected to one or more of the electrical components of the second module by one or more immobilized second electrical conductors; and', 'the first and second electrical connectors are either directly coupled to one another or electrically connected to one another by immobilized conductors,, 'wherein the electrical connection comprisesthe first module mechanically coupled to the second module by a non-rotational coupling, the non-rotational coupling comprises a male portion attached to one of the first and second modules and a female portion attached to the other one of the first and second modules, wherein engagement of the male portion and the female portion restricts the relative movement of the first and second modules.2. A downhole probe according to in which no electrical connections are made by way of wire harnesses in which wires are ...

Apparatus for angular alignment of downhole sensors with high side in directional drilling

Adjustment of the angle of a bent sub or other steering feature in a drill string relative to a reference angle of a downhole sensor is facilitated by a rotatable coupling between the bend sub and the sensor. The rotatable coupling may be rotated to align the high side with a reference indicia and locked at the set angle. Calibration of the sensor is facilitated and opportunities for certain measurement errors are eliminated. An embodiment provides a locking mechanism comprising tapered locking fingers which are clamped against a surface by a tapered collar. Rows of ceramic balls retained in circumferential channels may be provided to permit rotation while carrying tensile and compressional forces.

CENTRALIZER FOR DOWNHOLE PROBES

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. 1. A centralizer for use in subsurface drilling , the centralizer comprising:an elongated tubular member having a wall formed to provide a cross-section that provides first outwardly-convex and inwardly-concave lobes, the first lobes arranged to contact a bore wall of a bore in a section of drill string at a plurality of spots spaced apart around a circumference of the bore wall; anda plurality of inwardly-projecting portions, each of the plurality of inwardly-projecting portions arranged between two adjacent ones of the plurality of first lobes.2. A centralizer according to wherein the inwardly-projecting portions comprise inwardly-projecting lobes that are inwardly-convex and outwardly-concave.3. A centralizer according to wherein the inwardly-projecting lobes are symmetrical to one another.4. A centralizer according to wherein the inwardly-projecting lobes are mirror symmetrical about an axis passing through a longitudinal centerline of the centralizer.5. A centralizer according to wherein the inwardly-projection portions are shaped to conform to an outer surface of a downhole probe.6. A centralizer according to any one of to wherein a thickness of the wall is substantially uniform.7. A centralizer according to wherein the wall has a thickness in the range of about 0.1 to 0.3 inches (¼ cm to ¾ cm).8. A centralizer according to wherein the wall has a thickness of 0.15 to 0.25 inches (⅜ cm to ⅝ cm).9. A centralizer according to any one of to wherein claim 7 , in cross-section the centralizer has 4-fold rotational symmetry.10. A ...

AXIALLY-SUPPORTED DOWNHOLE PROBES

An assembly for use in subsurface drilling includes a downhole probe supported by a locking mechanism with a bore of a drill string section. The probe comprises a first spider and a second spider at the uphole and downhole sections of the probe. The locking mechanism secures the probes in the bore against axial and rotational movement relative the drill string section.

Fluid pressure pulse generating apparatus with primary seal assembly, back up seal assembly and pressure compensation device and method of operating same

The embodiments described herein generally relate to a fluid pressure pulse generating apparatus with a primary seal assembly, back up seal assembly and pressure compensation device. The pressure compensation device comprises a membrane support and a longitudinally extending membrane system. The membrane support has a longitudinally extending bore therethrough for receiving a drive-shaft of the fluid pressure pulse generating apparatus. The longitudinally extending membrane system comprising a longitudinally extending outer membrane sleeve and a longitudinally extending inner membrane sleeve with the inner membrane sleeve positioned inside the outer membrane sleeve. The membrane system is sealed to the membrane support to allow flexing of the membrane system in response to fluid pressure on either an inner longitudinal surface of the membrane system or an outer longitudinal surface of the membrane system and to prevent fluid on the inner longitudinal surface mixing with fluid on the outer longitudinal surface.

Downhole electromagnetic and mud pulse telemetry apparatus

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.

Back up directional and inclination sensors and method of operating same

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.

Multi-mode control of downhole tools

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.

Mud motor with integrated mwd system

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.

System and method for charging a capacitor used to power measurement-while-drilling equipment

A system for charging a capacitor used to power measurement-while-drilling equipment includes a power bus, which is electrically connected to the capacitor; a first pair of battery terminals; switching circuitry for electrically connecting the power bus to and disconnecting the power bus from the first pair of battery terminals; and a controller, for controlling the switching circuitry, which is configured to charge the capacitor by applying a first pulse width modulated control signal to control the switching circuitry. The first pulse width modulated control signal has a duty cycle selected such that the voltage of the first battery remains above a first minimum operating voltage while the capacitor is being charged.

Downhole telemetry tool with adaptive frequency transmitter

A method for selecting a drilling fluid pressure pulse transmission frequency in a downhole telemetry tool comprises: emitting a frequency sweep wave in a drilling fluid that comprises pressure pulses over a range of frequencies and over a period of time; measuring a pressure of the drilling fluid at the telemetry tool while the frequency sweep wave is being emitted; determining a signal strength at each frequency in the range of frequencies from the measured pressure of the drilling fluid; and selecting at least one frequency in the range of frequencies that meets a selected signal strength threshold as a telemetry signal transmission frequency for the telemetry tool. The method can further comprise encoding the at least one selected frequency in a header message and transmitting the header message to surface using pressure pulse telemetry, and then encoding telemetry data into a pressure pulse telemetry signal and transmitting the pressure pulse telemetry signal to surface at the at least one selected frequency.

Detection of downhole data telemetry signals

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.

Downhole telemetry signal modulation using pressure pulses of multiple pulse heights

A method for modulating a downhole telemetry signal uses a fluid pressure pulse generator that generates pressure pulses of multiple pulse heights in a drilling fluid. The method comprises: converting measurement data into a bitstream comprising symbols of a selected symbol set; encoding the bitstream into a pressure pulse telemetry signal using a modulation technique that includes amplitude shift keying, wherein each symbol of the selected symbol set is assigned a pressure pulse having a unique amplitude; and generating pressure pulses in the drilling fluid corresponding to the telemetry signal. Alternatively, the method can comprise a modulation technique that includes amplitude shift keying and phase shift keying and wherein each symbol of the selected symbol set is assigned a pressure pulse having a unique combination of amplitude and phase.

Detection of downhole data telemetry signals

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.

Method and apparatus for determining rotor position in a fluid pressure pulse generator

A method for determining a rotational position of a rotor in a fluid pressure pulse generator of a downhole telemetry tool comprises: for at least one rotational position of the rotor, determining an expected pressure of a drilling fluid at the fluid pressure pulse generator that corresponds to the at least one rotational position; forming a rotor position map of rotor rotational positions and corresponding expected drilling fluid pressures from the at least one rotational position of the rotor and the corresponding determined expected pressure; measuring a pressure of the drilling fluid at the fluid pressure pulse generator, and determining the rotational position of the rotor at the measured pressure by associating the measured pressure to an expected pressure and corresponding rotor rotational position in the rotor position map.

Method and system for transmitting a data frame of an electromagnetic telemetry signal to or from a downhole location

Methods, techniques, and systems for transmitting a data frame of an electromagnetic (EM) telemetry signal to or from a downhole location can be performed using multi-channel transmissions in which at least two different channels at two different frequencies are used to send a long header and the data frame. At least a portion of the long header is transmitted at a first frequency, and at least a portion of the data frame and any remaining portion of the long header not transmitted at the first frequency are transmitted at one or more additional frequencies different from each other and the first frequency. In one example, only two channels are used: one channel is used to transmit all of the long header, another channel is used to transmit all of the data frame, and either of the channels is used to transmit an identifier identifying the type of the data frame.

Device and method for securing conduit interior wear sleeve

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.

Electromagnetic telemetry system with compensation for drilling fluid characteristics

A downhole apparatus for measuring drilling fluid characteristics. The downhole apparatus may comprise one or more sensors located within a housing. The sensors may include one or more of an imaging device, a resistivity/conductivity sensor, a temperature sensor, a pressure sensor, a flowmeter and a fluid density sensor. The downhole apparatus may also include a controller for receiving measurements and/or determining optimal electromagnetic telemetry transmission settings. The downhole apparatus may also comprise a transmitter for transmitting the measurements and/or the optimal electromagnetic transmission settings. The downhole apparatus may be operated to determine optimal transmission settings for an electromagnetic telemetry system. Optimal transmission settings may include settings relating to one or more of frequency, amplitude, voltage, current, and power.

Universal downhole probe system

A downhole probe is adapted to be supported in drill string sections having different internal diameters with the use of a set of interchangeable centralizers. Each centralizer is dimensioned to snugly receive the downhole probe and to bear against the bore wall of a drill-string section. Interchangeable axial supports such as spiders may also be provided in a set. The downhole probe may comprise a slick body. As drilling progresses the downhole probe may be adapted to be received in drill string sections of varying diameters.

Fluid pressure pulse generator for a downhole telemetry tool

A fluid pressure pulse generator comprises a stator with a body and cylindrical bore and a generally cylindrical rotor having uphole and downhole ends with different diameters to form an annular fluid barrier at the intersection of the two ends. An annular gap is formed between the rotor uphole end and stator body. The stator body and rotor body collectively have a fluid flow chamber comprising a lateral opening and an uphole axial inlet, and a downhole axial outlet and fluid diverter comprising a lateral opening in fluid communication with the axial outlet. The annular fluid barrier is in fluid communication with the fluid flow chamber or the fluid diverter. The rotor can be rotated such that the fluid diverter is movable in and out of fluid communication with the fluid flow chamber to create fluid pressure pulses.

Integrated downhole system with plural telemetry subsystems

Abstract of the Disclosure 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. Date Recue/Date Received 2020-11-12

Mounting and component holder apparatuses and assemblies for holding rigid components

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 tubular housing, for example.

Fluid pressure pulse generator for a telemetry tool

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. The reduced outer diameter rotor and/or stator projections provide bypass channels for flow of fluid and allow for generation of a pattern of different fluid pressure pulses.

Integrated downhole system with plural telemetry subsystems

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.

At-surface communication with downhole tools

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.

Rotary locking sub for angular alignment of downhole sensors with high side in directional drilling

Adjustment of the angle of a bent sub or other steering feature in a drill string relative to a reference angle of a downhole sensor is facilitated by a rotatable coupling between the bent sub and the sensor. The rotatable coupling may be rotated to align the high side with a reference indicium and locked at the set angle. Rows of ceramic balls retained in circumferential channels may be provided to permit rotation while carrying tensile and compressional forces. Calibration of the sensor is facilitated and opportunities for certain measurement errors are eliminated. An embodiment provides a mechanism for locking the rotatable coupling at a desired angle. The embodiment comprises a ring with teeth that engage a downhole portion of the coupling and depressions that engage an uphole portion of the coupling.

Method and apparatus for multi-channel downhole electromagnetic telemetry

An electromagnetic (EM) telemetry method comprises encoding downhole data into a single data stream; separating the single data stream into a plurality of separate data streams; converting each separate data stream into a corresponding separate waveform using a selected digital modulation technique wherein at least one of the frequency and phase of each waveform is assigned a unique value or unique non- overlapping range of values; combining each separate waveform into a combined waveform; and transmitting from a downhole location, an electromagnetic (EM) telemetry carrier wave comprising the combined waveform.

Preloadable connectors for tubing

Connectors and connection systems for connecting two tubing sections together are provided. The connectors can include: a first end having an outer surface and adapted for insertion into an end of the tubing section and a second end adapted for connection to a second connector. The connector can have an attachment block in one aspect with a first threaded aperture and a second threaded aperture passing through it so that axial screws and radial screws can secure the connector to the end of a tubing section before it is connected to another connector. In another aspect, the connector can have an attachment slot provided in an outer surface of the first end of the connector sized to fit a retaining clips so that axial screws can secure the connector to an end of a tubing section before the connector is connected to another connector.

Device and method for securing conduit interior wear sleeve

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.

Fluid pressure pulse generating apparatus with primary seal assembly, back up seal assembly and pressure compensation device and method of operating same

The embodiments described herein generally relate to a fluid pressure pulse generating apparatus with a primary seal assembly, back up seal assembly and pressure compensation device. The pressure compensation device comprises a membrane support and a longitudinally extending membrane system. The membrane support has a longitudinally extending bore therethrough for receiving a driveshaft of the fluid pressure pulse generating apparatus. The longitudinally extending membrane system comprising a longitudinally extending outer membrane sleeve and a longitudinally extending inner membrane sleeve with the inner membrane sleeve positioned inside the outer membrane sleeve. The membrane system is sealed to the membrane support to allow flexing of the membrane system in response to fluid pressure on either an inner longitudinal surface of the membrane system or an outer longitudinal surface of the membrane system and to prevent fluid on the inner longitudinal surface mixing with fluid on the outer longitudinal surface.

Downhole pocket electronics

An assembly for use in subsurface drilling includes a drill collar section having a bore extending longitudinally through an inner surface of the drill collar section. A pocket is formed in a section of the inner surface of the drill collar section. A holster may be located in the pocket and a sleeve may be snuggly fitted inside the bore in order to secure the holster inside the pocket. The sleeve may be sealed to the drill collar section for example by seals such as O-rings such that the holster is sealed from the bore. O-rings may be located on one or both of the inside of the inner surface of the collar or on the outside of the sleeve.

Device and method for retaining probe exterior wear sleeve

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.

Fluid pressure pulse generator and method of using same

A fluid pressure pulse generator comprising a stator and rotor that can be used in measurement while drilling using mud pulse or pressure pulse telemetry is disclosed. The stator comprises a stator body with a circular opening therethrough and the rotor comprises a circular rotor body rotatably received in the circular opening of the stator body. One of the stator body or the rotor body comprises one or more than one fluid opening for flow of fluid therethrough and the other of the stator body or the rotor body comprises one or more than one full flow chamber. The rotor is rotatable between a full flow configuration whereby the full flow chamber and the fluid opening align so that fluid flows from the full flow chamber through the fluid opening, and a reduced flow configuration whereby the full flow chamber and the fluid opening are not aligned. The flow of fluid through the fluid opening in the reduced flow configuration is less than the flow of fluid through the fluid opening in the full flow configuration thereby generating a fluid pressure pulse.

Drill collar with integrated probe centralizer

An assembly for use in subsurface drilling includes a downhole probe supported in a drill string section by centralising features that are integral with the drill string section. A bore wall of the drill string section is fluted to provide inward contact points that support the downhole probe. The downhole probe may be supported for substantially its entire length. A vibration damping and/or electrically insulating material may optionally be provided between the downhole probe and the drill string section.

Universal downhole probe system

A downhole probe is adapted to be supported in drill string sections having different internal diameters with the use of a set of interchangeable centralizers. Each centralizer is dimensioned to snugly receive the downhole probe and to bear against the bore wall of a drill-string section. Interchangeable axial supports such as spiders may also be provided in a set. The downhole probe may comprise a slick body. As drilling progresses the downhole probe may be adapted to be received in drill string sections of varying diameters.

Automated drilling methods and systems using real-time analysis of drill string dynamics

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.

Electromagnetic communications system and method for a drilling operation

A wireless communications system for a downhole drilling operation comprises surface communications equipment and a downhole telemetry tool. The surface communications equipment comprises a surface EM communications module with an EM downlink transmitter configured to transmit an EM downlink transmission at a frequency between 0.01 Hz and 0.1 Hz. The downhole telemetry tool is mountable to a drill string and has a downhole electromagnetic (EM) communications unit with an EM downlink receiver configured to receive the EM downlink transmission. The downhole EM communications unit can further comprise an EM uplink transmitter configured to transmit an EM uplink transmission at a frequency greater than 0.5 Hz, in which case the surface EM communications module further comprises an EM uplink receiver configured to receive the EM uplink transmission. More particularly, the downhole EM uplink transmitter can be configured to transmit the EM uplink transmission at a frequency that is at least ten times higher than the EM downlink transmission frequency.

Downhole probe centralizer

An assembly for use in subsurface drilling includes a downhole probe supported in a drill string section by centralizing features of a centralizer that is slidably removable from the drill string section. The centralizer may comprise a tubular body having a bore defined through it. A bore wall of the centralizer is fluted to provide inward contact points that support the downhole probe. The downhole probe may be supported for substantially its entire length. The centralizer may optionally comprise and/or be coated with a vibration damping and/or electrically insulating material.

Optimizing electromagnetic telemetry transmissions

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.

System and method for charging a capacitor used to power measurement-while-drilling equipment

A system for charging a capacitor used to power measurement-while-drilling equipment includes a power bus, which is electrically connected to the capacitor; a first pair of battery terminals; switching circuitry for electrically connecting the power bus to and disconnecting the power bus from the first pair of battery terminals; and a controller, for controlling the switching circuitry, which is configured to charge the capacitor by applying a first pulse width modulated control signal to control the switching circuitry. The first pulse width modulated control signal has a duty cycle selected such that the voltage of the first battery remains above a first minimum operating voltage while the capacitor is being charged.

At-surface communication with downhole tools

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.

System and method for regulating an electromagnetic telemetry signal sent from downhole to surface

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.

Axially-supported downhole probes

An assembly for use in subsurface drilling includes a downhole probe supported by a locking mechanism with a bore of a drill string section. The probe comprises a first spider and a second spider at the uphole and downhole sections of the probe. The locking mechanism secures the probes in the bore against axial and rotational movement relative the drill string section.

Measurement while drilling fluid pressure pulse generator

A mechanical stop sub-assembly for a pulser assembly of a measurement-while-drilling telemetry apparatus comprises: a collar fixedly coupled to the housing and an indexer protruding from a side of a driveshaft such that a portion of the indexer protrudes from a side of the driveshaft. The indexer can be a coupling key that couples the driveshaft to a motor of the pulser assembly. The indexer can also comprise a key body and at least one zero backlash ring that extends around the key body and protrudes from surfaces of the key body and into a gap between the key body and a keyhole of the driveshaft. The collar comprises an angular movement restrictor window with a central window segment which axially and rotatably receives the driveshaft, and an indexing window segment in communication with the central window segment and which receives the indexer. The indexing window segment has an angular span across which the indexer can be oscillated by the driveshaft.

Battery coil engaging members for downhole tools

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.

Method for sealing a gap sub assembly

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.

Downhole electronic device carrier

一种钻柱部段，该钻柱部段接纳电子装置组件。流通道延伸穿过电子装置组件中的孔。流通道运送通过钻柱部段的钻井流体流。流通道被密封至钻柱部段的本体。电子装置组件不需要具有额定压力。

Fluid pressure pulse generator for a downhole telemetry tool

A fluid pressure pulse generator apparatus for a downhole telemetry tool, comprises a stator and a rotor. The stator has a stator body with a cylindrical central bore. The rotor has a cylindrical body and a cap. The cylindrical body has a smaller diameter than the diameter of the stator central bore such that an annular gap is formed when the rotor body is seated in the stator central bore. The cap is connected to an uphole end of the rotor body and has a base with a larger diameter than the diameter of the rotor body; the base forms a lip that protrudes laterally outwards from the rotor body and covers at least a portion of the annular gap when the rotor body is seated in the stator central bore. One of the stator body and rotor body has at least one fluid flow chamber comprising a lateral opening and an uphole axial inlet; the other of the stator body and rotor body has a downhole axial outlet and at least one fluid diverter comprising a lateral opening in fluid communication with the axial outlet. The rotor can be rotated relative to the stator such that the at least one fluid diverter is movable in and out of fluid communication with the at least one fluid flow chamber to create fluid pressure pulses in drilling fluid flowing through the fluid pressure pulse generator.

Gap assembly for em data telemetry

A gap sub has electrically-conductive parts held together by electrical insulators which engage in channels formed in the parts. The electrical insulators hold the parts in a spaced-apart electrically-insulated relationship. In some embodiments, the electrical insulators are removable to allow separation of the parts. An insulating oil or other fluid may fill the gap.

Centralizer for downhole probes

An assembly for use in subsurface drilling includes a downhole 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.

Optimizing downhole data communications using node and at-bit sensors

数据从钻头附近的井下位置处的传感器被传送至地面装备。可以直接或者可以通过一系列节点传送至地面装备。在一些情况下，节点被智能地重新配置成实现期望的数据速率，实现功率管理目标以及/或者补偿故障节点。

Apparatus for angular alignment of downhole sensors with high side in directional drilling

Adjustment of the angle of a bent sub or other steering feature in a drill string relative to a reference angle of a downhole sensor is facilitated by a rotatable coupling between the bend sub and the sensor. The rotatable coupling may be rotated to align the high side with a reference indicia and locked at the set angle. Calibration of the sensor is facilitated and opportunities for certain measurement errors are eliminated. An embodiment provides a locking mechanism comprising tapered locking fingers which are clamped against a surface by a tapered collar. Rows of ceramic balls retained in circumferential channels may be provided to permit rotation while carrying tensile and compressional forces.

Integrated downhole system with plural telemetry subsystems

A downhole system (50) has a plurality of telemetry systems and a control system (42) 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. Fig. 3 wO Of C /) Cl,- 0 0 Of zw 0w x 0 L 0oO cGo 0-_ _ _ _Q l w ( -- pop

Fluid pressure pulse generator for a downhole telemetry tool

A fluid pressure pulse generator for a downhole 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, whereby adjacently 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 to 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. The rotor projections may be positioned downhole of the stator projections and include a self-correction mechanism to move the rotor to an open flow position where the rotor projections are out of fluid communication with the stator flow channels if the telemetry tool fails. The stator body may be configured to fixedly attach to a pulser assembly of the downhole telemetry tool and the rotor may be configured to fixedly attach to a driveshaft of the pulser assembly with the driveshaft and/or the rotor body received within the bore of the stator body such that the stator projections are positioned between the pulser assembly and the rotor projections.

Electromagnetic communications system and method for a drilling operation

A wireless communications system for a downhole drilling operation comprises surface communications equipment and a downhole telemetry tool. The surface communications equipment comprises a surface EM communications module with an EM downlink transmitter configured to transmit an EM downlink transmission at a frequency between 0.01 Hz and 0.1 Hz. The downhole telemetry tool is mountable to a drill string and has a downhole electromagnetic (EM) communications unit with an EM downlink receiver configured to receive the EM downlink transmission. The downhole EM communications unit can further comprise an EM uplink transmitter configured to transmit an EM uplink transmission at a frequency greater than 0.5 Hz, in which case the surface EM communications module further comprises an EM uplink receiver configured to receive the EM uplink transmission. More particularly, the downhole EM uplink transmitter can be configured to transmit the EM uplink transmission at a frequency that is at least ten times higher than the EM downlink transmission frequency.

Optimizing downhole data communication with at bit sensors and nodes

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.

Preloadable connectors for tubing

Connectors and connection systems for connecting two tubing sections together are provided. The connectors can include: a first end having an outer surface and adapted for insertion into an end of the tubing section and a second end adapted for connection to a second connector. The connector can have an attachment block in one aspect with a first threaded aperture and a second threaded aperture passing through it so that axial screws and radial screws can secure the connector to the end of a tubing section before it is connected to another connector. In another aspect, the connector can have an attachment slot provided in an outer surface of the first end of the connector sized to fit a retaining clips so that axial screws can secure the connector to an end of a tubing section before the connector is connected to another connector.

Mud motor with integrated abrasion-resistant structure

A housing for a mud motor is disclosed. The housing comprises a female member comprising a female mating section and a male member comprising a male mating section and a housing section. The male mating section is matingly received within the female mating section. The collar is positioned on the housing section. The collar is made up of a framework with a plurality of discrete bodies spaced about the framework and a portion of each of the discrete bodies protrudes above the framework.

Integrated downhole system with multiple telemetry subsystems

井下系统具有多个遥测系统和控制系统，该控制系统被配置成从一个或更多个传感器获得信息并且在所述多个遥测系统中的一个或更多个遥测系统上传输信息。可以改变控制器的配置，以改变哪些信息在给定遥测系统上进行传输以及如何在给定遥测系统上传输该信息。

Sealed gap sub

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.

Centralizer for downhole probes

An assembly for use in subsurface drilling includes a downhole 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.

Apparatuses and methods for evaluating systems used in electromagnetic telemetry transmissions

Methods and systems for testing connectivity in an EM telemetry system for transmission of a ground originating uplink EM telemetry signal. The methods and systems comprise a switch coupled to the link and configured to selectively connect the link to a test signal generator or a signal receiver, the test signal generator configured to generate a test signal and to supply it to a ground conductor, and the current within the link is measured to determine whether the link and ground conductor can properly transmit the ground originating uplink EM telemetry signal.

Downhole telemetry tool with adaptive frequency transmitter

A method for selecting a drilling fluid pressure pulse transmission frequency in a downhole telemetry tool comprises: emitting a frequency sweep wave in a drilling fluid that comprises pressure pulses over a range of frequencies and over a period of time; measuring a pressure of the drilling fluid at the telemetry tool while the frequency sweep wave is being emitted; determining a signal strength at each frequency in the range of frequencies from the measured pressure of the drilling fluid; and selecting at least one frequency in the range of frequencies that meets a selected signal strength threshold as a telemetry signal transmission frequency for the telemetry tool. The method can further comprise encoding the at least one selected frequency in a header message and transmitting the header message to surface using pressure pulse telemetry, and then encoding telemetry data into a pressure pulse telemetry signal and transmitting the pressure pulse telemetry signal to surface at the at least one selected frequency.

Jig for coupling or uncoupling drill string sections with detachable couplings and related methods

A jig and method useful for coupling and/or uncoupling drill string sections. In some embodiments, the jig comprises a body having an outer surface for engaging a torqueing tool and a cavity extending from a first end to a second end of the body and an engagement means at the first end of the body. The engagement means may be dimensioned to non-rotationally engage an outer surface of a first end of a drill string section and the cavity may be sized to fit about a drill string section.

Fluid pressure pulse generator for a telemetry tool

A telemetry tool comprising a pulser assembly and a fluid pressure pulse generator. The pulser assembly comprises a housing enclosing a motor and a driveshaft rotationally coupled to the motor. The fluid pressure pulse generator comprises a stator fixedly attached to the housing or to a drill collar housing the fluid pressure pulse generator and a rotor fixedly attached to the driveshaft. The stator has an angular movement restrictor window with a central window segment which axially and rotatably receives a rotatable member comprising at least a portion of the driveshaft and/or a portion of the rotor, and an indexing window segment in communication with the central window segment which receives an indexer protruding from the rotatable member received in the central window segment. The indexing window segment has an angular span across which the indexer can be oscillated by the driveshaft, whereby the angular span of the indexing window segment defines the range of angular movement of the rotor relative to the stator.

Fluid pressure pulse generator and flow bypass sleeve for a telemetry tool

A fluid pressure pulse generator for a telemetry tool comprising a stator and a rotor. The stator comprising a stator body and a plurality of radially extending stator projections spaced around the stator body, whereby adjacently spaced stator projections define stator flow channels extending therebetween. The rotor comprising 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 generate fluid pressure pulses in fluid flowing through the stator flow channels. At least one of the rotor projections has an angled rotor bypass channel which moves in and out of fluid communication with the stator flow channels as the rotor rotates relative to the stator, the angled rotor bypass channel extending through or along a surface of the at least one rotor projection and having a fluid inlet and a fluid outlet downhole and lateral relative to the fluid inlet. The angled rotor bypass channel providing a self-correction mechanism causing the rotor to rotate to an open flow position when there is failure of the telemetry tool.

Fluid pressure pulse generator for a downhole telemetry tool

A fluid pressure pulse generator apparatus for a downhole telemetry tool comprises a stator and a rotor. The stator has a stator body with a cylindrical central bore and at least one fluid flow chamber comprising a lateral opening and an uphole axial inlet. The rotor comprises a cylindrical rotor body at least partially rotatably seated within the central bore, a rotor head connected to an uphole end of the rotor body, and a fluid diverter comprising a fluid passage through the rotor body and at least one nozzle in the rotor head. At least one fluid passage has at least one fluid opening on an outside surface of the rotor body and an axial outlet at a downhole end of the rotor body. The at least one nozzle has an inlet end fluidly communicable with a drilling fluid and an outlet end in fluid communication with the at least one fluid opening. The cross-sectional flow area of the at least one nozzle increases from the inlet end to the outlet end such that the velocity of the drilling fluid slows while flowing from the inlet end to the outlet end of the at least one nozzle. The rotor can be rotated relative to the stator such that the fluid diverter is movable in and out of fluid communication with the at least one fluid flow chamber to create fluid pressure pulses in the drilling fluid flowing through the pulse generator.

System and method for data telemetry among adjacent boreholes