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 retransmit the information in the form of a DMT-modulated signal.

Abstract: An embodiment includes an apparatus for wireless communications in a drilling operations environment. In an embodiment, the apparatus includes an instrument hub that is inline with drill pipe of a drill string. The instrument hub includes a sensor to receive downhole communications from downhole. The instrument hub also includes a transmitter to wireless transmit data representative of the downhole communications to a data processor unit.

Abstract: Therapeutic composition and method for treating or preventing various conditions and diseases, including inflammatory conditions, allergies, particularly seasonal allergies, and the common cold. In a preferred embodiment, the therapeutic composition is a formulation comprising an antibiotic, preferably a tetracycline, most preferably doxycycline, which has not been chemically modified to eliminate antimicrobial efficacy. The antibiotic is preferably in a vehicle to form a salve or paste for topical application to the skin or the nasal cavity. The therapeutic composition most preferably is a self-applied formulation that consists essentially of a tetracycline, most preferably doxycycline, which has not been chemically modified to eliminate antimicrobial efficacy, and a vehicle such as boric acid, zinc oxide or petroleum jelly.

Abstract: 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 data from the input data series as modulations of at least one of a plurality of evenly spaced frequency bins), and applying the information-carrying signal to a transducer that converts the information-carrying signal into pressure variations within a fluid.

Abstract: An embodiment includes a method comprising receiving an acoustic signal that is modulated along a jointed tubing. The method also includes performing equalization over a passband of the acoustic signal to generate an equalized signal.

Abstract: 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 detect an acoustic receive signal from the drillstring and a noise signal from a surface environment. The receiver operates on the acoustic receive signal and the noise signal to produce a modified signal indicative of the acoustic information signal and having a reduced noise content relative to the acoustic receive signal.

Abstract: 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 or more telemetry signals; generating a communications signal using the MCM parameters, and transmitting the communications signal via a communications channel. The MCM parameters may be determined by minimizing a telemetry signal distortion measure subject to CGNR and a transmit power constraint. The MCM parameters may further account for differing fidelity requirements when multiple telemetry signals are being transmitted.

Abstract: 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 acquired from a propagation along the drill string in an approximately noise free environment.

Abstract: Acoustic telemetry installation in subterranean wells. In a described embodiment, a method of contacting an assembly with a generally tubular string in a subterranean well includes the steps of: suspending the tubular string in the well, the tubular string extending into a surface structure; and then displacing the assembly through the structure into contact with an exterior of the tubular string. The assembly can selectively contact any one of several tubular strings or other objects within a wellhead or casing. The assembly can be permanently or temporarily used on the well.

Abstract: 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 joints.

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: 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 deflected into the dampening members for acoustically dispersal within the interior chamber. In various aspects thereof, the dampening members may include one or a group of two or more generally cylindrical sleeves having one end both physically and acoustically coupled to the housing and a second end projecting into the interior chamber. Preferably, when a group of two or more cylindrical sleeves are employed, the sleeves are nested within one another. The dampening members may further include a second, oppositely disposed, group of two or more acoustic attenuators nested within one another and interdigitated with the first group of cylindrical sleeves.

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: 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, and transmits a downlink signal to the downhole transceiver using a modulation method determined by the transceivers as communications are initiated. The downlink modulation methods supported by the surface transceiver may include DMT modulation and quadrature amplitude modulation (QAM). The modulation mode selection may be based on measured channel characteristics, on proposed data rates, or on other predetermined parameters. The uplink and downlink signals may be communicated over a shared transmission mode on multiconductor cable or wired pipe, and alternatively the uplink and downlink signals may be communicated over separate transmission modes.

Abstract: Therapeutic composition and method effective for reducing plaque formation and reducing tooth decay. The therapeutic composition is a formulation comprising an antibiotic, preferably a tetracycline, most preferably doxycycline, which optionally has not been chemically modified to eliminate antimicrobial efficacy. The antibiotic is preferably in a liquid vehicle, preferably one that contains at least 35%, most preferably 39% alcohol by volume. The teeth of a mammal are brushed with the therapeutic composition, preferably multiple times daily.

Abstract: A downhole telemetry system having a surface transceiver, a cable, and a downhole transceiver. The downhole transceiver transmits a first category of data over a first set of frequency subchannels and a second category of data over a second set of frequency subchannels. The frequency subchannels of the first set preferably have lower error rate than the frequency subchannels of the second set. The first category of data may include data from a tool, data from a group of sensors within a tool, data sampled from a data stream at a pre-determined frequency, or a combination thereof. In at least some embodiments, the first and second sets of frequency subchannels are at lower frequencies than a third set of frequency subchannels allocated for downlink communications.

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.