The disclosure generally relates to a method, apparatus and system to deploy aquatic sensors to obtain oceanographic data. In an exemplary embodiment, a free-floating or untethered sensor receives signals from different transmitters. The signals may be configured to travel through air and/or water. The sensor records each signals' time of arrival and determines its location in relationship to known transmitters based on the signal travel time. The position of each sensor may be determined by triangulation to several devices whose positions are known. The distances from the sensor in question to each device is measured by means of time-of-flight measurements for a wireless signal from the sensor to each known-position device. Other methods such as trilateration or dead-reckoning may also be used. The sensor may additionally collect and record oceanographic or other environmental data.

Methods, systems, and apparatuses are disclosed for conducting reconnaissance marine seismic surveys. In one example method of acquiring a marine seismic survey, a plurality of streamers are towed behind an acquisition vessel, the plurality of streamers defining a swath. A source is towed behind the acquisition vessel, and at least one other source is towed outside of the swath of streamers.

Deblending and deghosting seismic data may include processing blended seismic data acquired after actuation of a first seismic source located at a first depth and a second seismic source located at a second depth. The processing may comprise deblending and deghosting the blended seismic data based on a difference in ghost responses of the first seismic source and the second seismic source.

Embodiments of dynamic gain adjustments in seismic surveys are described. One method of acquiring a seismic survey includes determining an arrival time at a seismic receiver of a downgoing seismic wavefield associated with a seismic source based at least in part on an estimated position of the seismic source, an estimated position of the seismic receiver, or combinations thereof. The method also includes adjusting a gain of the seismic receiver based at least in part on the determined arrival time of the downgoing seismic wavefield in order to, for example, help prevent overdriving or clipping of the seismic receiver when the downgoing seismic wavefield arrives at or passes by the seismic receiver.

One embodiment includes receiving distributed acoustic sensing (DAS) data for responses associated with seismic excitations in an area of interest. The area of interest includes a sea surface, the water column, a seafloor, and a subseafloor. The seismic excitations are generated by at least one seismic source in the area of interest. The responses are detected by at least one fiber optic sensing apparatus configured for DAS that is in the water column, on the seafloor, in a wellbore drilled through the seafloor and into the subseafloor, or any combination thereof. The embodiment includes determining a function of speed of sound in water using the DAS data, and correcting a digital seismic image associated with the area of interest using the function of speed of sound in water to generate a corrected digital seismic image.

Systems, methods, and computer-readable media for estimating a component of a seismic wavefield. The method may include accessing marine seismic data comprising a plurality of discrete measurements of a seismic wavefield; processing the marine seismic data to determine a relationship between a plurality of components of the seismic wavefield and each of the discrete measurements; and estimating from the marine seismic data processed via the one or more processors, each component of the seismic wavefield separated from each of the other plurality of components of the seismic wavefield and evaluated at a predetermined position.

A method includes receiving, via a processor, input data based upon received seismic data, migrating, via the processor, the input data via a pre-stack depth migration technique to generate migrated input data, encoding, via the processor, the input data via an encoding function as a migration attribute to generate encoded input data having a migration function that is non-monotonic versus an attribute related to the input data, migrating, via the processor, the encoded input data via the pre-stack depth migration technique to generate migrated encoded input data, and generating an estimated common image gather based upon the migrated input data and the migrated encoded input data. The method also includes generating a seismic image utilizing the estimated common image gather, wherein the seismic image represents hydrocarbons in a subsurface region of the Earth or subsurface drilling hazards.

Method for acquiring, at reduced acquisition cost, seismic data using simultaneous, field-encoded sources in the field (702), and then constructing pseudo source-records (703) that better meet the requirements for using additional simultaneous computer-encoded sourcing for computer simulations or forward modeling (706) as part of (707) iterative FWI (Full Wavefield Inversion) or RTM (Reverse Time Migration), with additional reduction in computational costs. By better meeting the requirements of simultaneous sourcing for FWI or RTM (701), artifacts and crosstalk are reduced in the output. The method can be used for marine streamer acquisition and other non-fixed spread geometries to acquire both positive and negative offsets and to mitigate the “missing data” problem for simultaneous-source FWI. It can also be used for land data to overcome issues with moving spreads and long continuous records.

A method for obtaining zero-offset and near zero offset seismic data from a marine survey, with separation of direct arrival information and reflectivity information, the method including: modeling a direct arrival estimate at a passive near-field hydrophone array by using a notional source separation on active near-field hydrophone data; generating reflection data for the passive near-field hydrophone array by subtraction of the modeled direct wave from data recorded by the passive near-field hydrophone array; generating near zero-offset reflectivity traces by stacking the reflection data for the passive near-field hydrophone array on a string-by-string basis or on a combination of strings basis; generating reflectivity information at the active near-field hydrophone array by subtracting the direct arrival estimate modeled using the notional source separation from the active near-field hydrophone data; and generating an estimate of zero-offset reflectivity traces by calculating a cross-correlation between the between the reflectivity information at the active near-field hydrophone array and the near zero-offset traces and performing an optimized stacking with summation weights based on coefficients of the cross-correlation.

A hybrid, modularized, tailored and re-configurable distributed monitoring and characterization device for bodies of water and sediments, including oceans, lakes, rivers, and water reservoirs. The device includes individual nodes, which are deployed as either a stand-alone or networked system. Each node is a multi-physics and multi-purpose piece of equipment with electronics and sensors configured into different modules which interconnect similar to building blocks. The device provides two housing options: a hard shell housing option for shallow water and an oil-filled soft shell housing scheme for deep water.