In one or more embodiments, a system comprises a first (target) wellbore disposed in a formation, the first wellbore having a pressure imbalance therein causing an influx of formation fluids, a second (relief) wellbore disposed in the formation, a drill string disposed in the second wellbore, the drill string comprising a drill bit and a logging tool, and a wellbore ranging module comprising a processor and memory, the wellbore ranging module coupled to the drill string. The logging tool is configured to detect acoustic energy originating from the influx in the first wellbore and generate one or more signals associated with the detected acoustic energy. The wellbore ranging module is configured to receive, from the logging tool, the one or more signals associated with the detected acoustic energy and determine, using the received signals, a direction from the drill bit to the influx of the first wellbore.

In a method for acquiring data of azimuthal acoustic LWD, when an acoustic LWD instrument rotates with a drilling tool at a certain depth, data is acquired by adopting an azimuthal equal-interval mode: a well circumference is divided into m sectors by azimuthal intervals Δθ, when a toolface angle of the acoustic LWD instrument is located in the k.sup.th sector, an acoustic transmitting source is controlled to transmit an acoustic signal, and an acoustic receiver measures the acoustic signal, digitizes it and then stores it as data in the k.sup.th sector; and the data is acquired for each sector in turn, and after the data is acquired in each sector for N times, the data acquisition at the current depth is completed. Meanwhile, as the drilling tool rotates and drills, the instrument acquires acoustic data at different depths and processes it to achieve azimuthal acoustic imaging.

An automated slide drilling system (ASDS) may be used with a drilling rig system to control slide drilling. The ASDS may autonomously control slide drilling without user input during the slide drilling. The ASDS may further support a transition from rotary drilling to slide drilling to rotary drilling without user input during the transitions. The ASDS may also support user input and user notifications for various steps to enable manual or semi-manual control of slide drilling by a driller or an operator.

A method can include training a deep neural network to generate a trained deep neural network where the trained deep neural network represents functions of a nonlinear Kalman filter that represents a dynamic system of equipment and environment via an internal state vector of the dynamic system; generating a base internal state vector, that corresponds to a pre-defined operational procedure, using the trained deep neural network; receiving operation data from the equipment responsive to operation in the environment; generating an internal state vector using the operation data and the trained deep neural network; and comparing at least the internal state vector to at least the base internal state vector.

A modular downhole logging system includes a transmitter module having a local frequency, wherein the transmitter module transmits interrogation signals into a formation based on the local frequency. The downhole system also includes a receiver module axially-spaced from the transmitter module and that receives response signals corresponding to the interrogation signals, wherein the receiver module includes sampling logic and sync estimation logic. The sync estimation logic is configured to perform sync estimation operations including estimating the local frequency of the transmitter module based on analysis of response signal Fourier transform results corresponding to different frequencies. The sampling logic/clock is configured to sample the response signals based on the estimated local frequency of the transmitter module, wherein a processor derives formation property values using the sampled response signals.

Methods and systems for identifying a pay zone in a subterranean formation can include: logging a well extending into the subterranean formation including measuring bulk density, compressional wave travel time and shear wave travel time at different depths in the subterranean formation; calculating elastic attributes including acoustic impedance and compressional velocity-shear velocity ratio at different depths in the subterranean formation; and displaying and analyzing the calculated elastic attributes to identify the low resistivity pay zones.

A system can include a processor; memory operatively coupled to the processor; and processor-executable instructions stored in the memory to instruct the system to: receive a marker on a well log for a well in a geographic region; and iteratively propagate the marker automatically to a plurality of well logs for other wells in the geographic region.

A well tool can be used in a wellbore that can measure characteristics of an object in the wellbore. The well tool includes an ultrasonic transducer for generating an ultrasonic wave in a medium of the wellbore. The ultrasonic transducer includes a front layer, a rear layer, backing material coupled to the rear layer, and piezoelectric material coupled to the front layer and to the backing material. The rear layer can improve signal-to-noise ratio of the transducer in applications such as imaging and caliper applications.

The disclosure relates to a first method for determining a lithology of a subterranean formation into which a wellbore has been drilled. The method comprises receiving a set of measurement logs comprising one or more measurement logs, each representing a measured characteristic of the wellbore plotted according to depth. The measured characteristic include at least cuttings percentage and one or more additional measured characteristics. The method also includes segmenting the wellbore into regions based on identified change of trend in one or more of the measurement logs of the set, and sub-segmenting at least one region into zones based on detection of appearance or disappearance of a rock type in the cuttings percentage log, The method also includes determining, in each zone, a location, length and rock type of one or more layers based on a total percentage of each rock type in the zone in the cuttings percentage log and at least one of the additional measurement logs.

A deviated or horizontal wellbore is drilled in a geologic formation with a multiphase fluid including a gas by a rotating drill bit positioned at a downhole end of a drill string. Portions of the gas are released into the wellbore during the drilling. During the drilling, soundwaves are emitted into the geologic formation from within the wellbore by a set of acoustic emitters attached to the drill string. The received reflected soundwaves are transmitted by the set of solid acoustic couplers to a set of acoustic sensors contacting the solid acoustic couplers. The reflected soundwaves are received by the acoustic sensors. Rock properties of the geologic formation are determined based on the less attenuated reflected soundwaves transmitted to the acoustic sensors by the solid acoustic couplers. A drilling direction of the wellbore is adjusted based on the determined rock properties.