| Patent Number |
Title Of Patent |
Date Issued |
| 7443312 |
Downhole telemetry system having discrete multi-tone modulation with QAM fallback |
October 28, 2008 |
| Improved communication systems and methods are disclosed. In one embodiment, a downhole communications system comprises a downhole transceiver and a surface transceiver. The surface transceiver receives a discrete multi-tone (DMT) modulated uplink signal from the downhole transceiver |
| 7339494 |
Acoustic telemetry transceiver |
March 4, 2008 |
| One embodiment includes an apparatus that includes a piezoelectric transducer to generate an acoustic signal that is to modulate along a mandrel, wherein the piezoelectric transducer includes at least one piezoelectric element and at least one electrode that is without non-permanent |
| 7324010 |
Acoustic telemetry systems and methods with surface noise cancellation |
January 29, 2008 |
| Acoustic telemetry systems and methods with surface noise cancellation. One illustrative embodiment may include an acoustic telemetry system comprising a transmitter configured to generate an acoustic information signal that propagates along a drillstring, and a receiver configured to |
| 7301473 |
Receiver for an acoustic telemetry system |
November 27, 2007 |
| One embodiment includes a method comprising receiving an acoustic signal that is propagated along a drill string. The method also includes correlating the acoustic signal to a first stored acoustic signal representing a first symbol, wherein the first stored acoustic signal is acquir |
| 7268696 |
Directional signal and noise sensors for borehole electromagnetic telemetry system |
September 11, 2007 |
| An electromagnetic borehole telemetry system providing improved signal to noise ratio. Adaptive filters use noise channels as references to remove noise from the signal channel. Directional detectors provide a signal channel with reduced noise content and improved noise channels with |
| 7265682 |
Joint source-channel coding for multicarrier modulation |
September 4, 2007 |
| Methods and systems employing combined source-channel coding for multi-carrier modulation (MCM). In some embodiments, a described method comprises: estimating channel gain to noise ratio (CGNR) as a function of frequency bin; determining MCM parameters that minimize distortion of one |
| 7210555 |
Low frequency acoustic attenuator for use in downhole applications |
May 1, 2007 |
| An acoustic attenuator includes a housing having an inner side surface which defines an interior chamber and at least one dampening member both physically and acoustically coupled to the housing and projecting into the interior chamber. Acoustic energy propagating within the housing is |
| 7187298 |
Methods and systems for transmitting and receiving a discrete multi-tone modulated signal in a f |
March 6, 2007 |
| Methods and systems for transmitting and receiving a discrete multi-tone (DMT) modulated signal in a fluid. Some illustrative embodiments may be a method comprising transforming an input data series into an information-carrying signal (the information-carrying signal carrying input d |
| 7180825 |
Downhole telemetry system for wired tubing |
February 20, 2007 |
| A communications system employing discrete multi-tone ("DMT") modulated signals on a communications channel formed by inductively-coupled pipe. In one embodiment, the communications system includes a string of wired pipe joints that couple a transmitter to a receiver. Each pipe joint in |
| 7158446 |
Directional acoustic telemetry receiver |
January 2, 2007 |
| Acoustic telemetry devices and methods that provide directional detection. In one embodiment, a disclosed acoustic telemetry device comprises at least two acoustic sensors and an electronics module. A first of the acoustic sensors detects a communication signal that propagates along a |
| 7132958 |
Downhole telemetry system using multiple uplink modes as data channels using discrete multi-tone |
November 7, 2006 |
| A method and a downhole telemetry system a downhole telemetry system using discrete multitone modulation for transmitting a data stream over a plurality of transmission modes is provided. The downhole telemetry system includes a downhole transmitter, a cable, and a surface receiver. |
| 7068183 |
Drill string incorporating an acoustic telemetry system employing one or more low frequency acou |
June 27, 2006 |
| A drill pipe forms an acoustic transmission channel for data to be transmitted from a downhole transceiver to a surface transceiver. By positioning a first low frequency acoustic attenuator between a drill bit and the downhole transceiver, acoustic noise generated by the drill bit is |
| 7061932 |
Code-division multiple-access (CDMA) wireline telemetry system |
June 13, 2006 |
| A downhole telemetry system employing code division multiple access (CDMA) is disclosed. In one embodiment, the downhole telemetry system comprises one or more downhole transmitters and an uphole receiver. Each of the downhole transmitters transmits a corresponding uplink signal which is |
| 7042367 |
Very high data rate telemetry system for use in a wellbore |
May 9, 2006 |
| A very high data rate telemetry system is provided for use in a wellbore. In a described embodiment, a telemetry system includes multiple nodes positioned in the wellbore and distributed over a substantial length of the wellbore. The nodes simultaneously communicate with a remote locatio |
| 6978832 |
Downhole sensing with fiber in the formation |
December 27, 2005 |
| A portion of at least one fiber is moved from a wellbore into a formation such that the portion is placed to conduct a signal responsive to at least one parameter in the formation. One particular implementation uses fiber optic cable with a process selected from the group consisting of a |
| 6909667 |
Dual channel downhole telemetry |
June 21, 2005 |
| The present disclosure provides several methods for selecting and transmitting information from downhole using more than one channel of communication wherein data streams transmitted up each communications channel are each independently interpretable without reference to data provide |
| 6880634 |
Coiled tubing acoustic telemetry system and method |
April 19, 2005 |
| System, apparatus, and method of telemetering downhole sensor information to the surface while operations are performed in an oil or gas well using coiled tubing. Data are transmitted on coiled tubing as digital signals encoded in acoustic signals. In one implementation, a stripper packe |
| 6847034 |
Downhole sensing with fiber in exterior annulus |
January 25, 2005 |
| A portion of at least one fiber is moved into an exterior annulus of a well between a tubular structure in the well and the wall of the borehole of the well such that the portion is placed to conduct a signal responsive to at least one parameter in the exterior annulus. One particular |
| 6819260 |
Synchronous CDMA telemetry system for use in a wellbore |
November 16, 2004 |
| A synchronous CDMA telemetry system is provided for use in a wellbore. In one described embodiment, each data bit of digital outputs of multiple downhole data sources is multiplied by an orthogonal code unique to each data source. The resulting encoded outputs are modulated on a carrier |
| 6781521 |
Filters for canceling multiple noise sources in borehole electromagnetic telemetry system |
August 24, 2004 |
| An electromagnetic borehole telemetry system providing improved signal to noise ratio. Adaptive filters use noise channels as references to remove noise from the signal channel. Multiple noise channels are coupled to series connected adaptive filters for removing each noise source from t |
| 6781520 |
Motion sensor for noise cancellation in borehole electromagnetic telemetry system |
August 24, 2004 |
| An electromagnetic borehole telemetry system providing improved signal to noise ratio. Adaptive filters use noise channels as references to remove noise from the signal channel. Improved sensors provide noise channels with reduced signal content. Motion sensors are used to detect noise a |
| 6657597 |
Directional signal and noise sensors for borehole electromagnetic telemetry system |
December 2, 2003 |
| An electromagnetic borehole telemetry system providing improved signal to noise ratio. Adaptive filters use noise channels as references to remove noise from the signal channel. Directional detectors provide a signal channel with reduced noise content and improved noise channels with |
| 6657551 |
Downhole telemetry system having discrete multi-tone modulation and dynamic bandwidth allocation |
December 2, 2003 |
| A downhole telemetry system having discrete multi-tone modulation and dynamic bandwidth allocation is disclosed herein. In one embodiment, the downhole telemetry system comprises a surface transceiver, a cable, and a downhole transceiver coupled to the surface transceiver via the cable. |
| 6583729 |
High data rate acoustic telemetry system using multipulse block signaling with a minimum distanc |
June 24, 2003 |
| A reliable downhole acoustic telemetry system with increased data rate is disclosed. In one embodiment, the telemetry system includes a receiver having an envelope-detection demodulator and a multipulse-block distance detector that compares a baseband envelope signal to stored waveforms |
| 6580751 |
High speed downhole communications network having point to multi-point orthogonal frequency divi |
June 17, 2003 |
| A method and related apparatus for high speed digital data conmunications from multiple distributed modems to a single central modem or a common transmission medium. In one embodiment, multiple downhole modems, with each modem associated with a geophone, transmit data to a surface modem |
| 6400646 |
Method for compensating for remote clock offset |
June 4, 2002 |
| A system is disclosed for synchronizing a clock in a well containing a drill string with a clock located near the surface of the well. The system includes devices for transmitting and receiving a pair of acoustic signals between locations associated with each clock and processing those s |
| 6370082 |
Acoustic telemetry system with drilling noise cancellation |
April 9, 2002 |
| An acoustic telemetry system is disclosed that reduces any through-drillstring drilling noise which contaminates a through-drillstring telemetry signal. Normal filtering operations are provided to remove noise outside the frequency band of interest, and reference signal filtering ope |
| 6355928 |
Fiber optic tomographic imaging of borehole fluids |
March 12, 2002 |
| This invention provides a method and an apparatus for fiber optic tomographic analysis and imaging of fluids. This invention includes a method for providing information on downhole fluid flowing in a hydrocarbon well, utilizing at least one downhole tomograph chamber (10). Light is i |
| 6320820 |
High data rate acoustic telemetry system |
November 20, 2001 |
| A reliable, high data rate, downhole acoustic telemetry system is disclosed. In one embodiment, the acoustic telemetry system includes a tubing string with an acoustic transmitter and an acoustic receiver mounted on it. The acoustic transmitter transmits telemetry information by modu |
| 6229453 |
Method to transmit downhole video up standard wireline cable using digital data compression tech |
May 8, 2001 |
| Disclosed is a downhole video system that is suitable for use with a standard wireline transmission line, without the need for coaxial or fiber optic cable. A downhole video camera transmits a digitized video signal that may be multiplexed with orientation, sound, and other telemetry dat |
| 6172614 |
Method and apparatus for remote actuation of a downhole device using a resonant chamber |
January 9, 2001 |
| The method of remotely actuating a downhole device provides the initiation of an acoustic signal. The acoustic signal is amplified within a resonance chamber and is transmitted down a fluid column in the tubing string or in the annulus around the tubing string. The signal can be coded to |
| 6137747 |
Single point contact acoustic transmitter |
October 24, 2000 |
| The invention is an acoustic transmitter that imparts vibratory stresses onto a signal propagation medium such as oil well tubing when actuated by an electric driver. In one embodiment, the acoustic transmitter utilizes a mechanical driver that includes piezoelectric elements to generate |
| 5586084 |
Mud operated pulser |
December 17, 1996 |
| A poppet and orifice mud pulser assembly is disclosed for use in an MWD system. The mud pulser is capable of generating pressure pulses in the column of drilling mud of various amplitudes to increase the data rate of the mud pulse telemetry system. The mud pulser includes a piston assemb |
| 5515336 |
MWD surface signal detector having bypass loop acoustic detection means |
May 7, 1996 |
| An acoustic detector in a mud pulse telemetry system includes a bypass loop in parallel with a section of the main mud line that supplies drilling mud to a drill string. The detector includes a pair of pressure sensing ports in the bypass line, and one or more pressure transducers for de |
| 5490121 |
Nonlinear equalizer for measurement while drilling telemetry system |
February 6, 1996 |
| A nonlinear equalizer aids in transmitting data with more speed and accuracy by reducing nonlinear signal distortion such as found in a mud transmission channel in an MWD telemetry system. The nonlinear equalizer receives an input signal that is modified by at least one nonlinear fun |
| 5387907 |
High data rate wireline telemetry system |
February 7, 1995 |
| In a well logging tool forming a data stream for telemetry to the surface, an encoding system is located downhole cooperative with surface located decoding equipment. The encoder converts serial data into NRZ symbols, then duobinary code of seven levels and then into quadrature modulatin |
| 5365229 |
Adaptive telemetry system for hostile environment well logging |
November 15, 1994 |
| The operation of hostile environment logging tools at temperatures up to 250.degree. C. stresses not only the tools, it also places severe demands upon the wireline telemetry due to the wide variations in the logging cable transmission characteristics. A robust adaptive wireline telemetr |
| 5229765 |
SP noise cancellation technique |
July 20, 1993 |
| An adaptive transversal filter is incorporated with an SP conductor extending through a logging cable to the surface from an SP electrode supported on a sonde. This logging cable is operated in a noisy environment and there is the risk of noise on the logging cable obscuring the SP s |
| 5010333 |
Advanced digital telemetry system for monocable transmission featuring multilevel correlative co |
April 23, 1991 |
| The present disclosure is directed to an improved telemetry system and data recovery telemetry receiver apparatus for installation with a logging cable supported sonde. In the sonde, a data stream is modulated onto a carrier after conversion by an encoder. Encoding involves conversion fr |
