A seabed object detection system is provided. The system can include a receiver array including a first streamer and a second streamer. The system can include a first plurality of receivers coupled with the first streamer and a second plurality of receivers coupled with the second streamer. The system can include a receiver array cross-cable to couple with the first streamer and the second streamer. The system can include a source array including a first source and a second source. The system can include a first source cable coupled with the first source and a second source cable coupled with the second source. The system can include a source array cross-cable to couple with the first source cable and the second source cable. The system can include a first lateral cable to couple with a first diverter and second lateral cable to couple with a second diverter.

One or more first sensors may be configured to sense seismic signals and one or more second sensors may be configured to sense electromagnetic crosstalk signals. The second sensors are not responsive to the seismic signals. The data from the first and second sensors may be recorded as first data and second data, respectively. The first data may be modified based on the second data to remove the electromagnetic crosstalk noise form the seismic data.

An inline source can be used for a marine survey. For example, a marine survey vessel can tow source units in line. The source units can be actuated near-continuously to cause a respective signal emitted by each of the source units to be uncorrelated with signals emitted by other of the source units.

A method for generating an image of a subsurface based on blended seismic data includes receiving the blended seismic data, which is recorded so that plural traces have uncontaminated parts with different uncontaminated recording time lengths, selecting plural subgroups (SG1, SG2) of traces so that each subgroup (SG1) includes only uncontaminated parts that have a same uncontaminated recording time length, processing the traces from each subgroup to generate processed traces, mapping the processed traces to a same sampling, combining the processed traces from the plural subgroups (SG1, SG2) to generate combined processed traces, and generating an image of a structure of the subsurface based on the combined processed traces.

The present disclosure is directed to a MEMS-based rotation sensor for use in seismic data acquisition and sensor units having same. The MEMS-based rotation sensor includes a substrate, an anchor disposed on the substrate and a proof mass coupled to the anchor via a plurality of flexural springs. The proof mass has a first electrode coupled to and extending therefrom. A second electrode is fixed to the substrate, and one of the first and second electrodes is configured to receive an actuation signal, and another of the first and second electrodes is configured to generate an electrical signal having an amplitude corresponding with a degree of angular movement of the first electrode relative to the second electrode. The MEMS-based rotation sensor further includes closed loop circuitry configured to receive the electrical signal and provide the actuation signal. Related methods for using the MEMS-based rotation sensor in seismic data acquisition are also described.

Described herein is a method for acquiring data using a marine vibrator towed by a vessel, the method comprising: obtaining data comprising at least one nominal pre-plot position in a horizontal plane; monitoring a position of the marine vibrator in the and a speed of the vessel; determining an offset between the position of the marine vibrator and the nominal pre-plot position in the towing direction; based on the offset and the vessel speed, adjusting one or more survey parameters and driving the vibrator with a series of one or more sweeps so that a predetermined frequency in the sweep or a subsequent sweep is emitted when the position of the vibrator is within a maximum distance of the nominal pre-plot position.

A reflection full waveform inversion method updates separately a density model and a velocity model of a surveyed subsurface formation. The method includes generating a model-based dataset corresponding to the seismic dataset using a velocity model and a density model to calculate an objective function measuring the difference between the seismic dataset and the model-based dataset. A high-wavenumber component of the objective function's gradient is used to update the density model of the surveyed subsurface formation. The model-based dataset is then regenerated using the velocity model and the updated density model, to calculate an updated objective function. The velocity model of the surveyed subsurface formation is then updated using a low-wavenumber component of the updated objective function's gradient. A structural image of the subsurface formation is generated using the updated velocity model.

Determining locations to gather information to reduce the number of locations without reducing the information gathered is of key importance when such observations require drilling or other resource-intensive activities. By utilizing ergodic sampling, the same information (volume and/or resolution) may be obtained when compared to an exhaustive grid approach but with significantly fewer observations.

A method for correcting for distortions in a seismic acoustic wavefield produced by a seismic vibrator that is immersed in a fluid, the method comprising: applying a pilot signal to the vibrator such that an acoustic wavefield travels outwards from the interface between the vibrator outer surface and the fluid: using a sensor located within the fluid so as to be sensitive to a property of the wavefield in the fluid to monitor the property of the wavefield as a function of time: and using the measured property to determine a change in wet volume of a component of the vibrator as a function of time V(t) or derivatives of V(t), and using the determined wet volume V(t) or its derivatives to correct for distortions in the seismic data produced by the vibrator.

A modular seismic unit storage and handling system with a gantry robot and charging magazine is provided. The storage and handling system can include a storage container. The storage and handling system can include a top hat and a top hat extension. The storage and handling system can include an automated connection and charging magazine. The top hat can be connected to a gantry robot. The gantry robot can include a robotic arm.