Determining a type of annular material in a wellbore comprises measuring an acoustic noise of one or more reference materials and thereby generating a corresponding one or more acoustic profiles, monitoring the annular material with an acoustic sensor positioned in the wellbore and thereby obtaining an acoustic response of the annular material, comparing the acoustic response with the one or more acoustic profiles using a processor communicably coupled to the acoustic sensor, and characterizing the annular material based on the comparison of the acoustic response and the one or more acoustic profiles.

A method of monitoring a rock drilling and a rock drilling device includes generating a stress wave, which propagates in a tool of the rock drilling device, measuring the stress wave propagating in the tool and measuring a drilling parameter indicating a drilling penetration rate. The method further includes identifying, from the measured stress wave propagating in the tool, at least one of a compressive stress wave and a tensile stress wave of a reflected stress wave reflected from a rock to be drilled back to the tool, determining at least one property of the at least one of the compressive stress wave and the tensile stress wave of the reflected stress wave, detecting, on the basis of a change in the at least one property of the at least one of the compressive stress wave and the tensile stress wave, that the tool is approaching the cavity.

A vibration while drilling acquisition and signal processing system include a sensor assembly affixable to a drill string in a drilling unit and a sensor for detecting vibrations in the drill string. A first processor is in signal communication with the sensor and is programmed to digitally sample signals from the sensor. A transmitter in signal communication with the first processor communicates the digitized signals to a device disposed apart from the drill string. The first processor is programmed to operate the signal. An electric power source provides power to the sensor, the first processor and transmitter. Either or both the first processor and a second processor associated with the device is programmed to calculate properties of rock formations using only detected vibration signals from the drill string.

A drill bit includes multiple cutting devices and a microelectronics unit. Each cutting device of the multiple cutting devices includes a cutting layer formed to cut a rock formation and a capacitive sensor disposed adjacent the cutting layer. The capacitive sensor is configured to generate an electric field across the cutting layer and to transmit a signal corresponding to a voltage associated with the electric field. The microelectronics unit of the drill bit is configured to receive the signal from the capacitive sensor of each cutting device of the multiple cutting devices such that the microelectronics unit receives multiple signals and to determine an indicator of mechanical wear of the drill bit based on a change in the voltage associated with the electric field across the cutting layer of each cutting device of the multiple cutting devices using the multiple signals.

A drill bit includes multiple cutting devices and a microelectronics unit. Each cutting device of the multiple cutting devices includes a cutting layer formed to cut a rock formation and a capacitive sensor disposed adjacent the cutting layer. The capacitive sensor is configured to generate an electric field across the cutting layer and to transmit a signal corresponding to a voltage associated with the electric field. The microelectronics unit of the drill bit is configured to receive the signal from the capacitive sensor of each cutting device of the multiple cutting devices such that the microelectronics unit receives multiple signals and to determine an indicator of mechanical wear of the drill bit based on a change in the voltage associated with the electric field across the cutting layer of each cutting device of the multiple cutting devices using the multiple signals.

A method can include accessing data generated during field operations; analyzing at least a portion of the data as to legal tag property values; storing the legal tag property values in association with the data; and operating a computational framework in accordance with the legal tag property values.

Drilling systems and related methods are disclosed. A drilling system may include a drill bit positioned at an end of a drill string, and one or more sources and receivers positioned on the drill string behind the drill bit. The sources may be configured to emit signals into a medium surrounding a borehole in which the drill string extends, and the signals may cause a response in the medium at one or more predetermined positions ahead of the drill bit, and response signals may be measured by the one or more receivers. A processor may use the measured response signals to iteratively update an estimate of a property of the medium at the predetermined position, which in some embodiments, may be done using a sequential estimation process, as the drill string is advanced into the medium.

Techniques for determining a drill bit location includes identifying a plurality of acoustic energy signals received at a plurality of sets of acoustic receivers from a passive acoustic energy source that is part of a wellbore drilling system; processing the plurality of acoustic energy signals; determining a location of a drill bit of the wellbore drilling system based on the processed plurality of acoustic signals; and updating a geo-steering path of the drill bit based on the determined location of the drill bit.

A system and a computer-implemented include the following. A field dataset of seismic waves is received that is obtained by receivers during a drilling period from a drilling operation at a target well. The drilling period includes drilling and non-drilling phases. The field dataset is analyzed to determine locations of seismic waves. A reconstructed wavefield is determined by applying a passive seismic imaging condition over time and based on locations of the receivers. Using the reconstructed wavefield, a time series is computed for the seismic waves, and a time-frequency transform is applied on the time series. Sources and locations of tube waves resulting from acoustic signatures of the drill bit the drilling phases are determined. Sources and locations of the body waves caused by the tube waves are determined. A petrophysical model of the target well is updated in real-time based on the analyzing and the waves.

Systems and methods for performing focused blind deconvolution of signals received by a plurality of sensors are disclosed. In some embodiments, this may include determining a cross-correlation of first and second signals, obtaining a cross-correlation of a first response function and a second response function based on the cross-correlation of the first and second signals and subject to a first constraint that the first and second response functions are maximally white, and obtaining the first and second response functions based on the cross-correlation of the first and second response functions and subject to a second constraint that the first and second response functions are maximally front-loaded.