Abstract: A modem is described having a transceiver assembly, a non-transitory processor readable medium coupled to the transceiver assembly, transceiver electronics coupled to the transceiver and the non-transitory processor readable medium, and a power supply supplying power to the transceiver assembly and the transceiver electronics. The transceiver electronics are configured to calculate a size of an output bit stream based on an encoding scheme to encode for transmission data stored in the non-transitory processor readable medium, decimate the data if the size of the output bit stream exceeds a predetermined size, recalculate the size of the output bit stream, after decimation of the data, based on the encoding scheme to encode for transmission the decimated data, and encode the data using the encoding scheme.

Abstract: A method for configuring transmission signals is disclosed. The method includes receiving a signal from a downhole tool in a wellbore. The signal may include a telemetry portion and a noise portion. The method also includes reproducing the telemetry portion based at least partially on the signal. Further, the method includes subtracting the telemetry portion from the signal. The method includes estimating, based at least partially on the subtraction, the noise portion of the signal. The method also includes altering a transmission configuration of the downhole tool based at least partially on the noise portion of the signal.

Abstract: A method for transmitting signals in a subsea environment includes determining that a quality of an acoustic signal is below a threshold. The acoustic signal travels from a first device, through water in the subsea environment, to a second device. A parameter of the first device, the second device, or both is then adjusted to improve the quality of the acoustic signal when the quality of the acoustic signal is below the threshold.

Abstract: A method, subsea device, and system, of which the method includes acquiring data using one or more sensors of the subsea device, the data representing a subsea environment, compressing the data using one or more processors of the subsea device, transmitting the data wirelessly from the subsea device to the surface device, and decompressing the data using the surface device.

Abstract: A method for configuring transmission signals is disclosed. The method includes receiving a signal from a downhole tool in a wellbore. The signal may include a telemetry portion and a noise portion. The method also includes reproducing the telemetry portion based at least partially on the signal. Further, the method includes subtracting the telemetry portion from the signal. The method includes estimating, based at least partially on the subtraction, the noise portion of the signal. The method also includes altering a transmission configuration of the downhole tool based at least partially on the noise portion of the signal.

Abstract: A nuclear magnetic resonance (NMR) system includes a transmitter of an NMR tool to output a magnetic field pulse into a zone of interest, a receiver of the NMR tool to output an NMR echo data set produced from an interaction of the magnetic field pulse and the zone of interest, and an NMR echo processing module including a filter matched to a response of the NMR tool to output a filtered NMR echo data set from the NMR echo data set, wherein the filter is matched to an echo shape of the NMR echo data, is matched to an average of a selected signal spectra of the NMR echo data set, or dynamically changes in response to a measurement.

Abstract: An acoustic network is located in a formation traversed by a borehole having a pipe contained therein. The acoustic network includes a backbone network having a number of backbone modems engaging the pipe and acoustically communicating along the pipe using a first modulation technique. A number of end node modems acoustically communicate using a second modulation technique orthogonal to the first modulation technique. At least one of the backbone modems is a bridge hub modem that is coupled to both the backbone network and an end node modem and communicates with the backbone network using the first modulation technique and with the end node modem using the second modulation technique. The end node modems may have a hibernation mode defined by low energy usage with no transmission or receipt of data, and a transmission mode defined by transmission of data by the end node modem.

Abstract: Compression of multidimensional sonic data is disclosed. Example methods disclosed herein to compress input multidimensional sonic data include decorrelating the input multidimensional sonic data to determine decorrelated multidimensional sonic data. In some such examples, the input multidimensional sonic data has a plurality of dimensions corresponding to a respective plurality of azimuthal directions from which the input multidimensional sonic data was obtained. In such examples, the decorrelated multidimensional sonic data is decorrelated among the plurality of dimensions of the input multidimensional sonic data. Such example methods also include processing the decorrelated multidimensional sonic data to determine compressed data representative of the input multidimensional sonic data.

Abstract: Devices and methods for obtaining borehole images at a surface installation while a borehole-imaging downhole tool is logging a borehole are provided. One such method may involve, while the downhole tool is disposed in the borehole, obtaining a first borehole image at a first depth of investigation using the borehole-imaging downhole tool. Compression electronics may compress the first borehole image to obtain a first compressed borehole image. Compressing the first borehole image may involve exploiting a symmetry characteristic of the first borehole image to increase compression efficiency or exploiting a similarity of the first borehole image with a second borehole image to increase compression efficiency, or both. The compressed borehole image then may be efficiently transmitted to the surface installation via a telemetry system.

Abstract: Sensor array noise reduction is provided. Techniques involve systems and methods for reducing sensor array noise by estimating an instantaneous frequency of a coherent noise signal in a logging system. The instantaneous frequency may be estimated based on a rotation of an electric motor in the logging system, or may estimated by applying suitable signal processing algorithms on measurements in the logging system. A virtual measurement may be computer using the instantaneous frequency. The virtual measurement may be demodulated to obtain a baseband signal, and noise may be removed from the baseband signal to obtain a denoised signal.

Abstract: A method for improving a quality of data received from a downhole tool in a wellbore includes receiving a first block of data from a downhole tool in a wellbore. The first block of data represents a first measurement captured by the downhole tool during a first period of time. At least a portion of a bit budget for a second block of data is allocated to the first block of data to produce an updated first block of data. The method also includes receiving the second block of data from the downhole tool in the wellbore. The second block of data represents a second measurement captured by the downhole tool during a second period of time.

Abstract: A method for configuring transmission signals is disclosed. The method includes receiving a signal from a downhole tool in a wellbore. The signal may include a telemetry portion and a noise portion. The method also includes reproducing the telemetry portion based at least partially on the signal. Further, the method includes subtracting the telemetry portion from the signal. The method includes estimating, based at least partially on the subtraction, the noise portion of the signal. The method also includes altering a transmission configuration of the downhole tool based at least partially on the noise portion of the signal.

Abstract: Wireless communication and electromagnetic telemetry between various surface or downhole devices may be provided using two or more dipole antennas. The dipole antennas may be formed, for example, by electrically isolating, for each electric dipole antenna, two electrically conductive portions. The two electrically conductive portions are part of a downhole casing, a downhole liner, a completion, a production tube, or a downhole tool. The two or more electric dipole antennas are disposed in different sections of a completed well, in one or more lateral wells, in different completed wells, or in any combination of those. An electromagnetic signal is transmitting from at least one of the two or more dipole antennas and received at any other of the two or more dipole antennas, thereby providing telemetry or wireless communication between the dipole antennas of the petrophysical devices.

Abstract: A downhole tool and a wired drill string assembly including a downhole tool. The downhole tool includes a body having a first connector and a second connector. At least the first connector is configured to be connected to a wired drill pipe. The downhole tool also includes one or more electrical components coupled to the body and configured to receive a first signal and transmit a second signal. The downhole tool further includes a first transmission line extending along the body to the first connector and electrically connected to the one or more electrical components. The first transmission line is configured to be electrically connected to a transmission wire of the wired drill pipe when the wired drill pipe is connected to the first connector.

Abstract: Methods and systems are provided for tools having non-resonant circuits for analyzing a formation and/or a sample. For example, nuclear magnetic resonance and resistivity tools can make use of a non-resonant excitation coil and/or a detection coil. These coils can achieve desired frequencies by the use of switches, thereby removing the requirement of tuning circuits that are typical in conventional tools.

Abstract: Methods and systems are provided for tools having non-resonant circuits for analyzing a formation and/or a sample. For example, nuclear magnetic resonance and resistivity tools can make use of a non-resonant excitation coil and/or a detection coil. These coils can achieve desired frequencies by the use of switches, thereby removing the requirement of tuning circuits that are typical in conventional tools.

Abstract: In one aspect, a nuclear magnetic resonance (NMR) system includes a transmitter of an NMR tool to output a magnetic field pulse into a zone of interest, a receiver of the NMR tool to output an NMR echo data set produced from an interaction of the magnetic field pulse and the zone of interest, and an NMR echo processing module including a filter matched to a response of the NMR tool to output a filtered NMR echo data set from the NMR echo data set. In another aspect, a method of processing an NMR echo data set includes providing from an NMR tool the NMR echo data set produced from an interaction of a magnetic field pulse and a zone of interest, matching a filter to a response of the NMR tool, and filtering the NMR echo data set with the filter to produce a filtered NMR echo data set.

Abstract: Devices and methods for obtaining borehole images at a surface installation while a borehole-imaging downhole tool is logging a borehole are provided. One such method may involve, while the downhole tool is disposed in the borehole, obtaining a first borehole image at a first depth of investigation using the borehole-imaging downhole tool. Compression electronics may compress the first borehole image to obtain a first compressed borehole image. Compressing the first borehole image may involve exploiting a symmetry characteristic of the first borehole image to increase compression efficiency or exploiting a similarity of the first borehole image with a second borehole image to increase compression efficiency, or both. The compressed borehole image then may be efficiently transmitted to the surface installation via a telemetry system.

Abstract: Wireless communication and electromagnetic telemetry between various surface or downhole devices may be provided using two or more dipole antennas. The dipole antennas may be formed, for example, by electrically isolating, for each electric dipole antenna, two electrically conductive portions. The two electrically conductive portions are part of a downhole casing, a downhole liner, a completion, a production tube, or a downhole tool. The two or more electric dipole antennas are disposed in different sections of a completed well, in one or more lateral wells, in different completed wells, or in any combination of those. An electromagnetic signal is transmitting from at least one of the two or more dipole antennas and received at any other of the two or more dipole antennas, thereby providing telemetry or wireless communication between the dipole antennas of the petrophysical devices.

Abstract: A method for reconstituting a signal due to a flow distortion in a mud-pulse telemetry system, having steps of obtaining at least one parameter to be transmitted by a transmitter to a receiver through the mud-pulse telemetry system, estimating a change in a flow rate in a borehole fluid along a trajectory of the mud-pulse telemetry system undergoing a fluid distortion, estimating a Doppler rate of the signal traveling through the borehole fluid along the trajectory of the mud-pulse telemetry system, calculating a Doppler compensation value for the signal sent along the trajectory in the borehole fluid, transmitting the signal of the at least one parameter through the mud-pulse telemetry system, receiving a portion of the signal of the at least one parameter and reconstituting at least a portion of the signal using the Doppler compensation value.