Abstract: 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 the string possesses threaded ends configured for mechanically connecting with other pipe joints, a electrical or inductive coupler at each threaded end, and an insulated conductor that electrically connects the couplers. The transmitter and receiver communicate via DMT modulated signals transported by the wired pipe string. The system may further include multiple repeaters in the string. Each repeater may be configured to receive a DMT-modulated signal, to recover information from the DMT-modulated signal, and to re-transmit the information in the form of a DMT-modulated signal.

Abstract: 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 tubing string in a first direction. A second of the acoustic sensors is configured to detect the communication signal before the first acoustic sensor. The electronics module combines the detection signals from the acoustic sensors to obtain a combined signal that substantially excludes signals propagating in a direction opposite to the communication signal. Such signal suppression may significantly enhance the communication signal's signal-to-noise ratio, thereby increasing channel capacity. The acoustic telemetry device may be configured to support logging while drilling and/or full-duplex communication.

Abstract: 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 attenuated. Similarly, by positioning the surface transceiver between the top of the drill pipe and a second low frequency acoustic attenuator, acoustic noise generated by surface equipment is attenuated. In this manner, the first and second low frequency acoustic attenuators serve as terminators for the acoustic transmission channel.

Abstract: 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 fracturing process, an acidizing process, and a conformance process.

Abstract: 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 provided up the other of the communications channels. Preferred embodiments incorporate the use of a combination of at least two of mud-based telemetry, tubular-based telemetry, and electromagnetic telemetry to achieve improved results and take advantage of opportunities presented by the differences between the different channels of communication.

Abstract: 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 packer through which coiled tubing is moved into a well is operated between at least a first state and a second state; and an acoustic communication device responds to operation of the stripper packer such that when the stripper packer is in the first state, the acoustic communication device is decoupled from acoustic communication with the coiled tubing, but when the stripper packer is in the second state, the acoustic communication device is coupled for acoustic communication with the coiled tubing.

Abstract: 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 implementation uses fiber optic cable with a cementing process whereby flowing cementing fluid pulls the portion of the cable into the exterior annulus.

Abstract: A communication system usable in a borehole in which a downhole modem wirelessly communicates with a surface modem using discrete multi-tone (“DMT”) modulation. The communication may be one-way (i.e., from downhole modem to surface modem, or vice versa) or two-way between the two modems.

Abstract: 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 packer through which coiled tubing is moved into a well is operated between at least a first state and a second state; and an acoustic communication device responds to operation of the stripper packer such that when the stripper packer is in the first state, the acoustic communication device is decoupled from acoustic communication with the coiled tubing, but when the stripper packer is in the second state, the acoustic communication device is coupled for acoustic communication with the coiled tubing.

Abstract: 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 fracturing process, an acidizing process, and a conformance process.

Abstract: In a subterranean well completion a bi-directional signal transmission system includes an in-line acoustic transceiver mounted in a tubing string extending through the wellbore, the transceiver being disposed beneath a hanger structure engaging the tubing string. Via the tubing string the transceiver receives acoustic signals from well parameter sensing apparatus further downhole and converts the received acoustic signals to non-acoustic signals. The resulting non-acoustic signals are then transmitted upwardly through the hanger structure, to a signal receiving location, via cabling. In this manner, the hanger structure does not adversely affect the strength of either upwardly or downwardly transmitted signals traversing it. Alternatively, the acoustic well parameter signals received by the transceiver are converted to electromagnetic signals which pass through the earth, are picked up by a receiver external to the well completion, and then relayed to the receiving location.

Abstract: 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 implementation uses fiber optic cable with a cementing process whereby flowing cementing fluid pulls the portion of the cable into the exterior annulus.

Abstract: A method and apparatus for analyzing a deposited layer on the inner surface of a fluid container wall having inner and outer surfaces are disclosed. One embodiment of the method comprises (a) transmitting an acoustic signal from a transmitter at a first distance from the outer surface of the wall; (b) receiving a first received signal A, comprising a reflection from the wall outer surface; (c) receiving a second received signal B, comprising a reflection from the wall inner surface; (d) receiving a third received signal C from the wall inner surface; (e) calculating a coefficient Rwp from A, B and C, and (f) calculating a coefficient Rpd from A, B and Rwp, and calculating the acoustic impedance of the deposited layer Zd from Rwp, Rpd, and Zw, where Zw is the acoustic impedance of the material between the transmitter and the wall outer surface.

Abstract: A system of measuring properties, such as pressure, and transmitting measurements in a subterranean well. In a described example, a valve system includes a valve having a closure member. A sensor senses a pressure differential across the closure member. A tool positioned in the valve transmits power to the valve to operate the sensor, and the sensed pressure differential is transmitted from the valve to the tool.

Abstract: A process and apparatus for treating a wellbore, comprising subjecting a substantially same portion of the wellbore to vibratory waves produced by a plurality of vibratory wave generators. The vibratory waves may have about the same frequency or a plurality of frequencies, and the frequencies may partially overlap, not overlap, or be modulated across a range. Additionally, the frequencies may be modulated in an oval, hoop, and flexural modes. The vibratory waves may be produced by firing the vibratory wave generators simultaneously or in sequence. Combinations of a vibrating pipe, piston pulser, or valve may be used as vibratory wave generators. In a preferred embodiment, the thickness and change of thickness of a mudcake on the interior surface of a wellbore are measured to evaluate the effectiveness of the wellbore treatment.

Abstract: 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 provided up the other of the communications channels. Preferred embodiments incorporate the use of a combination of at least two of mud-based telemetry, tubular-based telemetry, and electromagnetic telemetry to achieve improved results and take advantage of opportunities presented by the differences between the different channels of communication.

Abstract: An acoustic telemetry system for use in a borehole achieves both bi-directional and multi-hop communications without need for a wireline. Each step in the communications link comprises a processor and transceiver, which communicate with adjacent transceivers to achieve self-optimization. During operation, if communications deteriorate, each pair of transceivers can re-initiate optimization and attempt to reset parameters to achieve improved communications. Similarly, the system can also re-calibrate periodically to assure that optimal conditions are maintained.

Abstract: 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 and indicates for each symbol interval the multipulse block having the waveform closest to the baseband envelope signal. The receiver may also include a timing recovery module that models the baseband envelope signal for the detected multipulse blocks and determines a distance for early-sampling and late-sampling of the baseband envelope signal. The timing recovery module then provides a sampling clock that minimizes the average difference between the early- and late-sampling distances. The telemetry system may further include a transmitter having an encoder and a modulator. The encoder converts a data signal into a sequence of multipulse blocks having a settling interval between the blocks.

Abstract: A system for monitoring the presence of deposits or buildup on the inside wall of a fluid-containing pipe comprises a pair of acoustic transmitters outside of the pipe and spaced apart along the length of the pipe and capable of transmitting an acoustic signal into the pipe wall, a pair of acoustic receivers outside of the pipe and spaced apart along the length of the pipe and capable of receiving an acoustic signal from the pipe wall, and a power source for causing the transmitters to transmit a signal.

Abstract: A system for monitoring the presence of deposits or buildup on the inside wall of a fluid-containing pipe comprises a pair of acoustic transmitters outside of the pipe and spaced apart along the length of the pipe and capable of transmitting an acoustic signal into the pipe wall, a pair of acoustic receivers outside of the pipe and spaced apart along the length of the pipe and capable of receiving an acoustic signal from the pipe wall, and a power source for causing the transmitters to transmit a signal.