Abstract: A method that includes obtaining a first acoustic signal and transforming the first acoustic signal into a first frequency spectrum using a frequency transformer, where the first frequency spectrum comprises a first plurality of frequency data points. The method further includes partitioning the first plurality of frequency data points into a first plurality of energy bands using an energy band partitioning function. The method further includes determining a representative frequency for each of the first plurality of energy bands and determining a representative amplitude for each of the first plurality of energy bands, where the representative amplitude is determined based on an energy conservation principle.

Abstract: A system includes an acoustic attenuation interface disposed between a first acoustic transmission conduit and a second acoustic transmission conduit. An acoustic signal source acoustically coupled to the first acoustic transmission conduit generates an acoustic signal. An acoustic noise source acoustically coupled to the second acoustic transmission conduit generates an acoustic noise. A first sensor is configured to detect a first composite signal including the acoustic signal after transmission through at least a portion of the first acoustic transmission conduit and an attenuated acoustic noise. A second sensor is configured to detect a second composite signal including the acoustic signal after transmission through at least a portion of the first acoustic transmission conduit and attenuated by the acoustic attenuation interface and the acoustic noise. An acoustic signal processing system is configured to determine a noise-reduced signal from the first composite signal and the second composite signal.

Abstract: A well site may include a wellbore extending into a subsurface formation and a drilling rig with a top drive and a drive shaft to rotate a drill string extending into the wellbore. The drill string includes a drill bit at an end distal to the drilling rig to cut rock of the subsurface formation to form the wellbore. Acoustic sensors may be positioned on the drive shaft, or the top drive, or the drill string. The acoustic sensors are configured to record and transmit drilling acoustic signals during a dummy drilling operation and a real drilling operation. A computer system may be in communication with the acoustic sensors. The computer system processes the drilling acoustic signals during the dummy drilling operation and the real drilling operation to minimize a drilling environmental effect by deducting a drilling environmental noise from the drilling acoustic signals to calculate clean drilling acoustic signals.

Abstract: Systems and methods include a computer implemented method for evaluating rock physical properties. Drilling acoustic signals are received in real time during a drilling operation through rock at a drilling location. Transformed data is generated in a frequency domain from the drilling acoustic signals. The transformed data includes frequency and amplitude information for the drilling acoustic signals. De-noised transformed data is generated from the transformed data by filtering noise including background noise generated in a recording system and top drive rotation generated traces. A lithological significant frequency range that includes de-noised significant data points is determined from the de-noised transformed data. Physical properties of the rock are determined in real time using drill bit rotation rates and the amplitudes of the de-noised significant data points.

Abstract: A system includes an acoustic attenuation interface disposed between a first acoustic transmission conduit and a second acoustic transmission conduit. An acoustic signal source acoustically coupled to the first acoustic transmission conduit generates an acoustic signal. An acoustic noise source acoustically coupled to the second acoustic transmission conduit generates an acoustic noise. A first sensor is configured to detect a first composite signal including the acoustic signal after transmission through at least a portion of the first acoustic transmission conduit and an attenuated acoustic noise. A second sensor is configured to detect a second composite signal including the acoustic signal after transmission through at least a portion of the first acoustic transmission conduit and attenuated by the acoustic attenuation interface and the acoustic noise. An acoustic signal processing system is configured to determine a noise-reduced signal from the first composite signal and the second composite signal.

Abstract: Systems and methods include a computer-implemented method for determining normalized apparent power. Drilling acoustic signals corresponding to a time domain and generated during drilling of a well. A fast Fourier transformation (FFT) is performed using the drilling acoustic signals to generate FFT data. Normalized FFT data is generated using normalization parameters and a drill string rotation rate record of a drill string used to drill the well. The drill string rotation rate is received during drilling. Normalized apparent power is determined from data points of a predetermined top percentage of the normalized FFT data within a lithological significant frequency range. The normalized apparent power is a measure of the power of the drilling acoustic signals and it is a function of the amplitude and frequency of the normalized FFT data. The lithological significant frequency range is a frequency range within which the drill sounds are more closely related with lithology.

Abstract: Some systems and methods for determining depths of subterranean formation layer tops while drilling through the subterranean formation include a drill bit, a drill rig, a microphone, a depth sensor, and a processor. While drilling the through the subterranean formation, the processor receives a measured sound from the microphone and a measured drill bit depth from the depth sensor, normalizes the measured sound across all measured drill bit depths, determines frequency information of the normalized sound for each depth of the plurality of depths, determines frequency spectrums of the normalized sound for one or more depths of the plurality of depths, transforms the frequency spectrums into a depth spectrum, and determines the depths of subterranean formation layer tops based on the depth spectrum.

Abstract: Example computer-implemented methods, media, and systems for evaluating density and seismic impedance values of geologic layers using drill bit sound during drilling are disclosed. One example computer-implemented method includes receiving an acoustic signal associated with a sound produced by a well tool implemented to perform a well operation by contacting a portion of a subterranean zone, where the acoustic signal includes a source acoustic signal and a reflected acoustic signal, the reflected acoustic signal is produced in response to the source acoustic signal, and the sound is produced during a drilling operation. The acoustic signal is processed to determine the source acoustic signal and the reflected acoustic signal. A first signal is determined based on the source acoustic signal. A second signal is determined based on the reflected acoustic signal. Properties of the subterranean zone are determined based on a convolution of the first signal and the second signal.

Abstract: Systems and methods include a computer-implemented method for determining normalized apparent power. Drilling acoustic signals corresponding to a time domain and generated during drilling of a well. A fast Fourier transformation (FFT) is performed using the drilling acoustic signals to generate FFT data. Normalized FFT data is generated using normalization parameters and a drill string rotation rate record of a drill string used to drill the well. The drill string rotation rate is received during drilling. Normalized apparent power is determined from data points of a predetermined top percentage of the normalized FFT data within a lithological significant frequency range. The normalized apparent power is a measure of the power of the drilling acoustic signals and it is a function of the amplitude and frequency of the normalized FFT data. The lithological significant frequency range is a frequency range within which the drill sounds are more closely related with lithology.

Abstract: Some systems and methods for determining depths of subterranean formation layer tops while drilling through the subterranean formation include a drill bit, a drill rig, a microphone, a depth sensor, and a processor. While drilling the through the subterranean formation, the processor receives a measured sound from the microphone and a measured drill bit depth from the depth sensor, normalizes the measured sound across all measured drill bit depths, determines frequency information of the normalized sound for each depth of the plurality of depths, determines frequency spectrums of the normalized sound for one or more depths of the plurality of depths, transforms the frequency spectrums into a depth spectrum, and determines the depths of subterranean formation layer tops based on the depth spectrum.

Abstract: Apparatus and methods of identifying rock properties in real-time during drilling, are provided. An apparatus includes an acoustic sensor installed in a drilling fluid circulation system of a drilling rig, the acoustic sensor coupled to one of the following: (i) a bell nipple, (ii) a gooseneck, or (iii) a standpipe. Raw acoustic sensor data generated real-time as a result of rotational contact of the drill bit with rock during drilling is received, and a plurality of acoustic characteristics are derived from the raw acoustic sensor data. The lithology type of rock undergoing drilling may be determined from the acoustic characteristics. Petrophysical properties of the rock undergoing drilling may be determined using a petrophysical properties evaluation algorithm employable to predict the petrophysical properties of rock undergoing drilling from the raw acoustic sensor data.

Abstract: Systems and methods include a computer implemented method for evaluating rock physical properties. Drilling acoustic signals are received in real time during a drilling operation through rock at a drilling location. Transformed data is generated in a frequency domain from the drilling acoustic signals. The transformed data includes frequency and amplitude information for the drilling acoustic signals. De-noised transformed data is generated from the transformed data by filtering noise including background noise generated in a recording system and top drive rotation generated traces. A lithological significant frequency range that includes de-noised significant data points is determined from the de-noised transformed data. Physical properties of the rock are determined in real time using drill bit rotation rates and the amplitudes of the de-noised significant data points.

Abstract: A central member defines a sample chamber and includes an elastic material configured to enclose at least a portion of a sample, acoustic sensors configured to detect sound waves in the sample chamber, and acoustic emitters configured to emit sounds waves in the central member. A pressure-retaining case is configured to contain a pressurized fluid between an annulus formed between the pressure-retaining case and the central member. A switch is configured to connect or disconnect a pulser and receiver circuit to a specified emitter of the acoustic emitters. A data acquisition unit is configured to receive a signal from each of the acoustic sensors. A pulser and receiver circuit is configured to send an electric pulse to an acoustic emitter and a control signal to the data acquisition unit.

Abstract: A central member defines a sample chamber and includes an elastic material configured to enclose at least a portion of a sample, acoustic sensors configured to detect sound waves in the sample chamber, and acoustic emitters configured to emit sounds waves in the central member. A pressure-retaining case is configured to contain a pressurized fluid between an annulus formed between the pressure-retaining case and the central member. A switch is configured to connect or disconnect a pulser and receiver circuit to a specified emitter of the acoustic emitters. A data acquisition unit is configured to receive a signal from each of the acoustic sensors. A pulser and receiver circuit is configured to send an electric pulse to an acoustic emitter and a control signal to the data acquisition unit.

Abstract: A central member defines a sample chamber and includes an elastic material configured to enclose at least a portion of a sample, acoustic sensors configured to detect sound waves in the sample chamber, and acoustic emitters configured to emit sounds waves in the central member. A pressure-retaining case is configured to contain a pressurized fluid between an annulus formed between the pressure-retaining case and the central member. A switch is configured to connect or disconnect a pulser and receiver circuit to a specified emitter of the acoustic emitters. A data acquisition unit is configured to receive a signal from each of the acoustic sensors. A pulser and receiver circuit is configured to send an electric pulse to an acoustic emitter and a control signal to the data acquisition unit.

Abstract: Apparatus, computer readable medium, and program code for identifying rock properties in real-time during drilling, are provided. An example of an embodiment of such an apparatus includes a downhole sensor subassembly connected between a drill bit and a drill string, acoustic sensors operably coupled to a downhole data interface, and a surface computer operably coupled to the downhole data interface.

Abstract: Apparatus and methods of identifying rock properties in real-time during drilling, are provided. An apparatus includes an acoustic sensor installed in a drilling fluid circulation system of a drilling rig, the acoustic sensor coupled to one of the following: (i) a bell nipple, (ii) a gooseneck, or (iii) a standpipe. Raw acoustic sensor data generated real-time as a result of rotational contact of the drill bit with rock during drilling is received, and a plurality of acoustic characteristics are derived from the raw acoustic sensor data. The lithology type of rock undergoing drilling may be determined from the acoustic characteristics. Petrophysical properties of the rock undergoing drilling may be determined using a petrophysical properties evaluation algorithm employable to predict the petrophysical properties of rock undergoing drilling from the raw acoustic sensor data.

Abstract: A central member defines a sample chamber and includes an elastic material configured to enclose at least a portion of a sample, acoustic sensors configured to detect sound waves in the sample chamber, and acoustic emitters configured to emit sounds waves in the central member. A pressure-retaining case is configured to contain a pressurized fluid between an annulus formed between the pressure-retaining case and the central member. A switch is configured to connect or disconnect a pulser and receiver circuit to a specified emitter of the acoustic emitters. A data acquisition unit is configured to receive a signal from each of the acoustic sensors. A pulser and receiver circuit is configured to send an electric pulse to an acoustic emitter and a control signal to the data acquisition unit.

Abstract: Apparatus and methods of identifying rock properties in real-time during drilling, are provided. An apparatus includes an acoustic sensor installed in a drilling fluid circulation system of a drilling rig, the acoustic sensor coupled to one of the following: (i) a bell nipple, (ii) a gooseneck, or (iii) a standpipe. Raw acoustic sensor data generated real-time as a result of rotational contact of the drill bit with rock during drilling is received, and a plurality of acoustic characteristics are derived from the raw acoustic sensor data. The lithology type of rock undergoing drilling may be determined from the acoustic characteristics. Petrophysical properties of the rock undergoing drilling may be determined using a petrophysical properties evaluation algorithm employable to predict the petrophysical properties of rock undergoing drilling from the raw acoustic sensor data.

Abstract: Apparatus and methods of identifying rock properties in real-time during drilling, are provided. An apparatus includes an acoustic sensor installed in a drilling fluid circulation system of a drilling rig, the acoustic sensor coupled to one of the following: (i) a bell nipple, (ii) a gooseneck, or (iii) a standpipe. Raw acoustic sensor data generated real-time as a result of rotational contact of the drill bit with rock during drilling is received, and a plurality of acoustic characteristics are derived from the raw acoustic sensor data. The lithology type of rock undergoing drilling may be determined from the acoustic characteristics. Petrophysical properties of the rock undergoing drilling may be determined using a petrophysical properties evaluation algorithm employable to predict the petrophysical properties of rock undergoing drilling from the raw acoustic sensor data.