Abstract: The present disclosure is directed to a system to locate seismic data acquisition units in a marine environment. The system can include a first seismic data acquisition unit. The first seismic data acquisition unit can include a case having a wall defining an internal compartment, a power source, a clock, a seismic data recorder, and at least one geophone disposed within the case. The system can include a flexible connector and a telltale component, wherein the flexible connector and the telltale component can be stored adjacent to the first seismic data acquisition unit, wherein a second seismic data acquisition unit is coupled with the first seismic data acquisition unit.

Abstract: An acoustic logging tool may comprise a center load carrying pipe, a receiver module connected to the center load carrying pipe, one or more transmitter modules connected to the center load carrying pipe, and one or more mass modules connected to the center load carrying pipe.

Abstract: A system to perform marine surveying may include a pair of identical design autonomous marine survey vehicles configured for coordinated operations. The vehicles may navigate and transit from a launch location to a geographically distant designated survey location, continuously survey and transit to a designated recovery location. A pair of vehicles may operate interchangeably at the sea surface, semi-submerged and underwater. Each may generate energy when operating at the surface and store energy in a rechargeable battery to power vehicle operation. The payload may include a sensor system to acquire seabed sensor data. A data storage system may store the sensor data. An on-board payload quality control system may analyze data validity. Positioning when the vehicle is collecting seabed sensor data may be determined with high precision, to provide survey data of high precision.

Abstract: Aspects of the present disclosure include methods for communication using a MIMO channel, such as an acoustic channel for underwater communication. An acoustic receiver may receive a signal comprising information encoded in at least one transmitted symbol. Using a two-layer iterative process, the at least one transmitted symbol is estimated. The first layer of the two-layer process uses iterative exchanges of soft-decisions between an adaptive turbo equalizer and a MAP decoder. The second layer of the two-layer process uses a data-reuse procedure that adapts an equalizer vector of both a feedforward filter and a serial interference cancellation filter of the adaptive turbo equalizer using a posteriori soft decisions of the at least one transmitted symbol. After a plurality of iterations, a hard decision of the bits encoded on the at least one transmitted symbol is output from the MAP decoder.

Abstract: The present disclosure is directed to delivering nodes to an ocean bottom. A system can include a tether management system (TMS) towed by a vessel that moves on the surface of the ocean in a first direction. An underwater vehicle (UV) can be connected to the TMS and can move in a second direction that is different from the first direction. A thruster can be coupled to the TMS can cause the TMS to move in a third direction that is different from the first direction. A control unit can control the thruster to move the TMS in the third direction based on a cross-line location policy, and cause the UV to deploy nodes to target locations on the ocean bottom.

Abstract: A method and apparatus for marine surveying. A system includes: a standard-volume source element; a large-volume source element comprising an airgun having a volume greater than 1200 cubic inches; and a long-offset survey streamer. A method includes: towing a standard-volume source element; and towing a large-volume source element; activating the large-volume source element at large shotpoint intervals; and activating the standard-volume source element at standard shotpoint intervals, wherein the large shotpoint intervals are at least twice as long as the standard shotpoint intervals. A method includes: obtaining geophysical data for a subterranean formation; and processing the geophysical data to produce an image of the subterranean formation. A method includes: obtaining a firing plan for a plurality of seismic sources, wherein: a first seismic source of the plurality comprises a large-volume source element, and a second seismic source of the plurality consists of standard-volume source elements.

Abstract: Embodiments, including systems and methods, for remotely controlling underwater vehicles (such as ROVs) and deploying ocean bottom seismic nodes from the underwater vehicles. A direct data connection may be created between an Integrated Navigation System (located on a surface vessel) and a ROV controller/Dynamic Positioning (DP) system (which may be located on the surface vessel and/or the ROV). The INS may be configured to output the ROV target position and ROV position (such as standard 2 or 3 dimensional coordinates) to the DP system. The DP system may be configured to calculate the necessary ROV movements based on directly received data from the INS. Based on a selected ROV target destination or desired ROV action (which may be done automatically or by an operator), the ROV may be automatically positioned and/or controlled based on commands from the DP system based on commands and/or data from the INS.

Abstract: Performing retrospective dynamic transmit focusing beamforming for ultrasound signals by a) transmitting plural transmit beams, each transmit beam centered at a different position along array, having width or aperture encompassing plural laterally spaced line positions, each transmit beam width or aperture overlapping width or aperture of adjacent transmit beam or more laterally spaced transmit beams; b) receiving echo signals; c) processing echo signals to produce plural receive lines of echo signals at laterally spaced line positions within width or aperture of transmit beam; d) repeating steps b), (c) for additional transmit beams of plural transmitted transmit beams; e) equalizing phase shift variance among receive lines at common line position resulting from transmit beams of different transmit beam positions concurrently with steps c), d); f) combining echo signals of receive lines from different transmit beams spatially related to common line position to produce image data; g) produces an image using i

Abstract: In a method for transmit beamforming of a two-dimensional array of ultrasonic transducers, a beamforming pattern to apply to a beamforming space of the two-dimensional array of ultrasonic transducers is defined. The beamforming space includes a plurality of elements, where each element of the beamforming space corresponds to an ultrasonic transducer of the two-dimensional array of ultrasonic transducers, where the beamforming pattern identifies which ultrasonic transducers within the beamforming space are activated during a transmit operation of the two-dimensional array of ultrasonic transducers, such that a generated ultrasonic beam is focused for reflecting from an object in contact with a contact surface of a platen overlying the two-dimensional array of ultrasonic transducers. The beamforming pattern is applied to the two-dimensional array of ultrasonic transducers. A transmit operation is performed by activating the ultrasonic transducers of the beamforming space according to the beamforming pattern.

Abstract: A marine survey node can include a body to be deployed to a seabed, a marine survey receiver coupled to the body and to acquire marine survey data, and a soil sample module associated with the body to collect a soil sample from the seabed. A soil sample module can include a vessel, a first valve coupled to the vessel, and a spike coupled to the vessel. The spike can penetrate an earth surface. The first valve can maintain a pressure difference between the vessel and the spike when closed and equalize a pressure between the vessel and the spike when open. An inlet in the spike can equalize pressure between an inside of the spike and an outside of the spike and to collect a soil sample from the earth surface.

Abstract: An example system can comprise autonomous submarines and an auxiliary station including a power supply. Each autonomous submarine can include a respective power supply and a respective marine survey node coupled thereto. The auxiliary station can be configured to dock the autonomous submarines in a body of water and recharge the respective power supply of each of the autonomous submarines via the power supply of the auxiliary station. Each autonomous submarine can be configured to autonomously navigate from and return to the auxiliary station and position the respective marine survey node on an underwater surface.

Abstract: Methods of designing seismic survey and acquisition of seismic data with reduced noise using equally or optimally irregularly spaced sources or receivers are described. Specifically, prime number ratios for the station to line spacing is used to prevent harmonic leakage and other noise contaminations in the acquired seismic data.

Abstract: An autonomous underwater seismic wave generation system includes a housing, and an autonomous navigation system, a propulsion system and a seismic wave generator, each connected to the housing. The autonomous navigation system can navigate the autonomous underwater seismic wave generation system to subsea locations including a location on a seabed. The propulsion system can drive the autonomous underwater seismic wave generation system to the location on the seabed. The seismic wave generator can couple to the location on the seabed to generate seismic waves at the location on the seabed.

Abstract: Disclosed are advantageous designs for highly-sparse seabed acquisition for imaging geological structure and/or monitoring reservoir production using sea surface reflections. The highly-sparse geometry designs may be adapted for imaging techniques using the primary and higher orders of sea surface reflection and may advantageously allow for the use of significantly fewer sensors than conventional seabed acquisition. The highly-sparse geometry designs may be relevant to 3D imaging, as well as 4D (“time-lapse”) imaging (where the fourth dimension is time). In accordance with embodiments of the invention, geophysical sensors may be arranged on a seabed to form an array of cells. Each cell in the array may have an interior region that contains no geophysical sensors and may be sufficiently large in area such that a 500 meter diameter circle may be inscribed therein.

Abstract: Systems and computer readable media are described that actuate at least one marine seismic source according to a constrained sequence. The sequence exhibits an actuation time or distance interval between each actuation. The actuation time or distance interval corresponds to the sum of a nominal time or distance and a respective dither time or dither distance for each actuation. The sequence is constrained such that differences between consecutive dither times or dither distances remain within a threshold dither difference. Constraining the sequence according to the threshold dither difference enables increased bottom speeds for the source (i.e., increased speeds of the source relative to the seafloor), while still maintaining at least a minimum actuation time or distance interval for the source, taking into account both the nominal time or distance and the respective dither times or dither differences.

Abstract: A marine seismic data acquisition system includes a streamer spread including plural streamers; a first set of front sources configured to generate seismic waves; a streamer vessel towing the streamer spread and the first set of the front sources, in front of the streamer spread along an inline direction X; a second set of top sources configured to generate additional seismic waves; and first and second source vessels towing the second set of top sources directly above or below the streamer spread. A number NT of the top sources is larger than a number NF of the front sources.

Abstract: According to an embodiment, a device comprises: a piezoelectric element configured to convert an electrical voltage into a mechanical strain; and a conductive base plate onto which the piezoelectric element is fastened, wherein the conductive base plate comprises an integrated support positioned on an underside of the conductive base plate, wherein the conductive base plate is supported by the integrated support; wherein the device is configured to provide haptic feedback on a basis of the mechanical strain.

Abstract: The present disclosure provides systems and methods associated with mode conversion for ultrasound and acoustic radiation devices. A method is disclosed for manufacturing a mode converting structure comprising a holographic metamaterial that, when positioned relative to an acoustic radiation device (AR), modifies an acoustic field profile of the AR device from an input mode to an output mode, the method including identifying a volumetric distribution of acoustic material properties within the mode converting structure to transform an input pressure field distribution of acoustic radiation in the input mode to an output field distribution of acoustic radiation that approximates the target radiation pattern in the output mode and manufacturing the mode converting structure using the identified volumetric distribution of acoustic material properties.

Abstract: Methods and systems are disclosed for determining a material property transition within a wellbore. In some embodiments, a method includes determining a material transition profile for each of a plurality of test points within a linear measurement path including, for each test point, determining an acoustic response for a first location within the linear measurement path, and determining an acoustic response for a second location within the linear measurement path. The test point is between the first and second locations. The method further includes generating a material transition profile for the test point based, at least in part, on a difference between the acoustic response at the first location and the acoustic response at the second location.

Abstract: A transducer probe includes a transducer array with rows of transducer elements that each extend in an elevation direction and is transverse to an azimuth direction, a matching layer disposed adjacent to the transducer array, and a focusing layer disposed adjacent to the matching layer. The focusing layer includes a first material with a first refractive index and a second material with a second refractive index, and the first refractive index is less than the second refractive index. The first and second materials are distributed in an alternating pattern with the first material at edges of the rows. First widths of the first material decrease from the edges towards a center of the rows, and second widths of the second material increase from the edges towards the center.