Abstract: Methods and apparatus for automatic recognition of environmental parameters with azimuthally distributed transducers. For example, a toolstring is disposed in a cased portion of a borehole penetrating a subsurface formation. The toolstring comprises a module comprising azimuthally distributed acoustic transducers each operable to emit and receive acoustic signals. The module is operated to emit an acoustic signal into fluid surrounding the module in the casing and record data indicative of receipt, by a plurality of the transducers, of acoustic waveforms resulting from interaction of the emitted acoustic signal with the casing, including at least a non-specular diffraction head wave excited by a guided wave that is excited by diffraction of the acoustic signal propagating in the casing metal. Acoustic velocity of the guided wave in the casing metal is determined utilizing the recorded data and geometric parameters of the module.

Abstract: Various embodiments include apparatus and methods implemented to take into consideration gauge length in optical measurements. In an embodiment, systems and methods are implemented to interrogate an optical fiber disposed in a wellbore, where the optical fiber is subjected to seismic waves, and to generate a seismic wavefield free of gauge length effect and/or to generate a prediction of a seismic wavefield of arbitrary gauge length, based on attenuation factors of a plurality of wavefields acquired from interrogating the optical fiber. In an embodiment, systems and methods are implemented to interrogate an optical fiber disposed in a wellbore, where the optical fiber is subjected to seismic waves, and to convert a seismic wavefield associated with a first gauge length to a seismic wavefield associated with a different gauge length that is a multiple of the first gauge length. Additional apparatus, systems, and methods are disclosed.

Abstract: Example ultrasonic acoustic sensors for measuring formation velocities are disclosed herein. An example sensor includes a housing, a first transmitter carried by the housing, a second transmitter carried by the housing, and a receiver array carried by the housing and disposed between the first transmitter and the second transmitter. The first transmitter is disposed at a first angle relative to a surface the housing and the second transmitter is disposed at second angle relative to the surface the housing.

Abstract: A ranging system comprises a plurality of receivers. A plurality of transmitters is configured to generate acoustic or ranging signals over one or more channels. A processor is configured to define a subset of the transmitters within a predefined limited range or listening distance of each receiver. In the subset, the transmitters are configured to generate the acoustic signals over different channels.

Abstract: The present disclosure relates to a seismic imaging free gas structure identification method and system. The method includes: acquiring a seismic imaging dataset, and annotating free gas structures in the seismic imaging sample data set to obtain a training dataset; using a generative adversarial network (GAN) to expand the training dataset for network training, wherein the GAN includes a generative network and a discrimination network; conducting domain conversion on original label data of the free gas training samples to obtain annotating labels; training a Bayesian neural network according to the free gas training datasets and labels, to obtain a free gas structure identification model; acquiring actual seismic imaging data of a target work area; and conducting, according to the actual seismic imaging data, identification by using the free gas structure identification model.

Abstract: Provided is a swim bladder bionic amphibious optical fiber ocean acoustic sensor, belonging to the field of optical fiber ocean sensors, consisting of a sound sensitive diaphragm, a diaphragm supporting shell, a section of coated optical fiber, a single-hole optical fiber sleeve and a single-mode optical fiber. An upper surface of the supporting shell is provided with two symmetrical overflow holes, and a structure includes a back cavity communicated with the overflow holes. A medium in the back cavity of the sensor may be replaced by inflating, deflating and filling water through the overflow holes, to achieve impedance matching with external environments. When the back cavity is inflated, the sensor serves as a fiber-optic microphone, and when the back cavity is deflated and filled with water, the sensor serves as a fiber-optic hydrophone. The working states could be switched flexibly to achieve a working mode like a swim bladder.

Abstract: A seismic pressure and acceleration sensor can include a hydrophone having a volume encapsulated by an enclosure. The enclosure can include, a pressure-sensitive surface and a pressure-insensitive support structure. The sensor can also include an accelerometer positioned within the encapsulated volume. The accelerometer is mechanically isolated from the pressure-sensitive surface and mechanically coupled to the pressure-insensitive support structure.

Abstract: A system and method of obtaining a high SNR seismic while-drilling data and a robust velocity profile of a geological site having a main well and at least one uphole located in the vicinity of the main well, the seismic profile being obtained from seismic waves generated by a drilling device located at the main well. The method comprises deploying at least one distributed acoustic fiber optic cable vertically in the at least one uphole, at least a portion of the fiber optic cable being positioned at a depth exceeding a predetermined depth below the surface, receiving seismic data at recording station positioned on the at least one fiber optic cable at at least the predetermined depth, generating, at a processor a high SNR seismic while-drilling signal; yielding a reliable velocity profile from the seismic data received, and determining a presence of near surface hazards from the generated high SNR while drilling seismic data.

Abstract: Techniques and apparatus are disclosed for performing marine seismic surveys. In some embodiments, one or more vessels are used to tow a set of streamers and two or more sources such that a first set of sources consists of all those that are disposed within a first threshold distance from the streamers, and a second set of sources consists of all those that are disposed beyond a second, greater, threshold distance from the streamers. Sources in the first set are activated more frequently than sources in the second set are activated.

Abstract: Techniques are disclosed relating to marine geophysical surveys. Various output characteristics of a vibratory source may be modified based on whether a source is targeting an identified portion of a survey area. The portion of the survey area may be detected during the survey or may be pre-identified. In some embodiments, a survey system drives a vibratory source using digital codes having different lengths based on whether the source is targeting an identified portion of a survey area. The disclosed techniques may improve imaging of geology under certain types of formations or may reduce environmental impact, in various embodiments.

Abstract: Included are methods and apparatus for marine geophysical surveying. One embodiment of the presently-disclosed solution relates to a method for instantaneous roll compensation of vectorised motion data originating from a fixed-mount geophysical sensor during a marine seismic survey. A streamer is towed behind a survey vessel in a body of water. The streamer includes a plurality of geophysical sensors and a plurality of orientation sensor packages. Vectorised geophysical data is acquired using the plurality of geophysical sensors, while orientation data is acquired by the plurality of orientation sensor packages. The orientation data is used to determine an instantaneous roll angle of the streamer at different positions on the streamer. The vectorised geophysical data is adjusted to compensate for the instantaneous roll angle of the streamer at different positions on the streamer. Other embodiments and features are also disclosed.

Abstract: Disclosed is a combined submarine seismic acquisition node with a secondary positioning function, including an ocean bottom node connected with an external loading ship; a protective sleeve circumferentially covering outside the ocean bottom node; and response components fixed inside the ocean bottom node, and the response components are configured to send position information of the ocean bottom node, and the response components may perform an information interaction with the loading ship.

Abstract: A downhole device is provided that is intended to be co-located with an optical fiber cable to be found, for example by being fixed together in the same clamp. The device has an accelerometer or other suitable orientation determining means that is able to determine its positional orientation, with respect to gravity. A vibrator or other sounder is provided, that outputs the positional orientation information as a suitable encoded and modulated acoustic signal. A fiber optic distributed acoustic sensor deployed in the vicinity of the downhole device detects the acoustic signal and transmits it back to the surface, where it is demodulated and decoded to obtain the positional orientation information. Given that the device is co-located with the optical fiber the position of the fiber can then be inferred. As explained above, detecting the fiber position is important during perforation operations, so that the fiber is not inadvertently damaged.

Abstract: A device and method to compress and store ultrasound data from an ultrasound logging device. The logging device is deployed in a well or pipe to be logged with one or more ultrasound transducers, preferably an array of transducers. On-board the device, are processors and memory units for convolving the ultrasound data with a wavelet transformation to generate wavelet coefficients and then compress the wavelet coefficients to generate compressed wavelet coefficients. The compressed wavelet coefficients are stored on the memory units and transferred to a remote computer once the device leaves the well or pipe.

Abstract: Embodiments of the present disclosure provide a real-time microseismic magnitude calculation method based on deep learning and a corresponding device. The method includes: constructing a DAS-based horizontal well microseismic monitoring system; constructing a training data set; constructing a magnitude calculation module, wherein the magnitude calculation module comprises two input branches of frequency spectrum and time waveform, the two input branches use a 3-layer convolution structure to extract frequency characteristic and waveform characteristic of a microseismic event, and then a model fusion is performed, and then 2 fully connected layers are used, and finally a calculated magnitude is outputted; training the magnitude calculation module; and analyzing and processing field data.

Abstract: A method for seismic exploration of a subsurface formation with a seismic survey system includes directly receiving a message, at a first fleet of seismic sources, from a second fleet; storing the message at the first fleet; verifying one or more constraints related to the first and second fleets, at the first fleet; initiating a triggering sequence of the seismic sources of the first fleet, upon verification of the one or more constraints, with no input from a central unit of the seismic survey system; and performing a sweep based on the triggering sequence.

Abstract: A logging tool for performing well logging activities in a geologic formation has one or more transmitters, one or more receivers, and a tool wave propagating factor which differs from a formation wave propagating factor. The one or more transmitters excite a tool wave and formation wave. The tool wave is reduced by the one or more transmitters transmitting an acoustic wave which causes the tool wave to be reduced. Additionally, or alternatively, the tool wave is reduced by generating an inverse estimate of the tool wave based on waveform data associated with the tool wave and formation wave received by each of the one or more receivers.

Abstract: The present invention provides a five-component marine natural gas hydrate intelligent sensing node, comprising a titanium alloy compartment, an information acquisition unit, an integrated control chip, and a power module; the integrated control chip comprises an intelligent computing unit and a transmission unit; the intelligent computing unit is configured for acquiring quality monitoring indicators of marine natural gas hydrates by feature extraction and transmitting reduced represented features to a monitoring device on the sea surface via the transmission unit.

Abstract: The present disclosure discloses a method of obtaining a seismic while drilling signal. The method comprises the following steps: arranging geophones by using a first observation method to obtain a first seismic reference signal and a second seismic reference signal; arranging geophones by using a second observation method to obtain first seismic data; arranging geophones by using a third observation method to obtain second seismic data; comparing the first seismic reference signal with the second seismic reference signal to obtain a first output reference signal, and optimizing the first output signal to obtain a second output reference signal.

Abstract: A method and apparatus for data acquisition including: acquiring a first set of data for a survey area with streamer receivers on a streamer spread; and simultaneously acquiring a second set of data for the area with ocean bottom receivers, the first and second sets of data together forming a complete dataset for velocity modeling and imaging. A method including: navigating a first propulsion source along a first path in the area, wherein a streamer spread and a first seismic source are coupled to the first propulsion source; navigating a second propulsion source along a second path in the area, wherein a second seismic source is coupled to the second propulsion source; while navigating the first and second propulsion sources, activating at least one of the first and second seismic sources; and acquiring data with receivers on the streamer spread and with ocean bottom receivers distributed throughout the area.