This disclosure presents processes and systems for estimating a source wavelet from seismic data recorded in a seismic survey of a subterranean formation. In one aspect, a base wavelet is determined based on recorded seismic traces obtained in a seismic survey of a subterranean formation. Processes and systems include a phase-only wavelet based on the base wavelet and the recorded seismic data. An estimated source wavelet is obtained by convolving the base wavelet with the phase-only wavelet. Properties of the subterranean formation are determined based on the estimated source wavelet and the recorded seismic data.

A method for imaging non-specular seismic events as well as correlating non-specular events with physically measurable quantites in a volume of Earth's subsurface. Includes entering as input to a computer signals detected by a plurality of seismic sensors disposed above and/or within the volume in response to actuation of at least one seismic energy source above and/or within the volume. Parameter analysis is performed to populate the initial model with point-wise, best-fit wavefront travel-time approximations. Imaging is performed to obtain undifferentiated specular and non-specular representations of the volume. Specular boundaries are mapped using the imaged volume and using the boundaries to form a model of specular components of the volume. Beamforming is used to characterize seismic attributes associated with specular and non-specular reflections as separate and differentiated data sets.

A seismic survey system for prospecting for sub-sea minerals including a first vessel towing a first seismic source and a seismic detector and a second vessel towing a second seismic source. The seismic detector is arranged to receive acoustic signals resulting from the reflection and/or refraction by the sea bed of acoustic signals emitted from both the first and second seismic sources.

Marine surveys carried out with multiple source arrays comprising three or more sources are discussed. Each source of a multiple source array is an array of source elements, such as air guns. The sources of a multiple source array may be arranged in particular type of configuration that is effectively maintained while the survey vessel travels a sail line. The sources of the multiple source array are activated to acoustically illuminate a subterranean formation with acoustic signals. Two or more sources of a multiple source array may be activated to create blended seismic data. Methods to deblend, source deghost, and attenuate noise in the blended seismic data obtained by using a multiple source array are also discussed.

Processes and systems are described for generating an image of a subterranean formation from seismic data recorded during a marine survey that employed a moving vibrational source. Processes and systems compute an up-going pressure wavefield from pressure data and vertical velocity data recorded in the marine survey. A direct incident downgoing vertical velocity wavefield that includes Doppler effects created by the moving vibrational source and characterizes a source wavefield and source ghost of the moving vibrational source is computed and deconvolved from the upgoing pressure wavefield to generate a subsurface reflectivity wavefield. The subsurface reflectivity wavefield is effectively free of contamination from the source wavefield, the source ghost, and the Doppler related effects. Processes and systems generate an image of the subterranean formation based on the subsurface reflectivity wavefield, thereby enhancing resolution of the image by attenuating the source-motion effects, source signature, and source ghost of the moving vibration source.

An attachment system for releasably attaching a sensor node to a cable when in a coupled state includes a clamp base and a clamp grip. The clamp base is fixed to a surface of the sensor node. The clamp base further includes a latch that is biased in a latched position when the attachment system is in both the coupled state and an uncoupled state. The clamp grip is pivotably attached the clamp base and biased in an open position when the attachment system is in the uncoupled state. The clamp grip is secured to the clamp base by the latch when the attachment system is in the coupled state.

An autonomous sensor node for undersea seismic surveying is formed as a sphere with density similar to sea water in order to minimize effects of noise. The node is capable of measuring both seismic pressure waves and water-borne particle velocity in three dimensions. The node floats above the seafloor to greatly decrease the impact of shear wave noise contamination generated by seabed waves. The node is attached to an anchor resting on the seabed by a tether. The tether is configured to prevent transfer of any tensile forces caused by shear waves in the seabed stratum from the anchor to the node. The tether may have a varying density along its length to entirely attenuate any force transfer from the seafloor.

A lift based acoustic source is towable in an undersea environment by a towing vessel. A controller provides a combined lift control signal and an acoustic source signal. A control cable is joined between the towing vessel and a towed depressor having an active lift control system. The combined signal is used to control the towed depressor active lift control system. The towed depressor lift fluctuates in response to the source signal to generate the undersea acoustic signal. A hydrophone or hydrophone array can be provided for measuring the generated acoustic signal for feedback and monitoring.

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.

Computing device, computer instructions and method for processing input seismic data d. The method includes receiving the input seismic data d recorded in a first domain by seismic receivers that are towed in water, the input seismic data d including pressure data and/or and particle motion data; generating a model p in a second domain to describe the input data d; processing the model p to generate an output particle motion dataset; and generating an image of the surveyed subsurface based on the output particle motion dataset.