Techniques are disclosed relating to geophysical surveying. In some embodiments, a marine survey vessel tows multiple sensor streamers including a group of four innermost streamers in a cross-line direction relative to a centerline of tow. In some embodiments, the vessel tows two or more vibratory sources between two outermost streamers in the first group, in a cross-line direction. In some embodiments, the two or more sources are simultaneously operated using different codes that are uncorrelated to at least a threshold degree. Various disclosed narrow-tow techniques may allow increased streamer separation without reducing cross-line bin size and/or reduce cross-line bin size for a given streamer separation, relative to conventional techniques.

A marine source element is configured to generate seismic waves. The source element includes a body and a source actuator attached to the body and configured to generate the seismic waves. The body is autonomous from a vessel towing streamers along a pre-plot line associated with a seismic survey.

A system and method for performing seismic exploration with multiple acquisition systems is disclosed. The method includes configuring a first seismic source located outside of an exclusion zone and configuring a second seismic source located inside of the exclusion zone. The method further includes obtaining a first seismic dataset corresponding to a first seismic signal emitted by the first seismic source and obtaining a second seismic dataset corresponding to a second seismic signal emitted by the second seismic source. The method further includes combining the first and second datasets to create a complete dataset covering a survey area and creating a seismic image of a subsurface of the survey area.

A tow body arrangement for a towable device in a sonar system includes a bridle having a front for connecting to a first tow cable and back for connecting to a second tow cable. The tow body arrangement also includes a tow body rotatably connected to the bridle between the front and back of the bridle. The tow body is shaped to generate hydrodynamic forces tending to rotate the tow body perpendicular to a longitudinal axis of the bridle.

According to an embodiment, there is provided a system and method of collecting seismic data using a predetermined pattern of source activations that is intended to control the properties of the resulting seismic signal. One embodiment utilizes a seismic source array (or, more generally, any collection of controllable sources) to create a series of spaced apart in time source activations, with the spacing and number of such activations being used to shape the resulting signal. In one method of building sweeps, the guns are fired at an increasing rate (decreasing time separation) as time goes by. Other patterns may be generated by decreasing the firing rate as time goes by, or some combination of the foregoing. In an embodiment, the rate of the increase or decrease in the firing rate will change from pattern to pattern.

Methods and devices for imaging wells using ultrasound is described. The devices include a modular imaging device having a telemetry module and a radial imaging module and/or forward imaging module. The radial imaging module includes a ring shaped phased array ultrasonic transducer array for generating images on the length of a wellbore. Various lens and housing configurations for the radial imaging module are described. The forward imaging module includes an ultrasonic transducer comprising one or more elements and having an adjustable viewpoint for generating images of obstructions found in a wellbore. Advanced imaging modes for a radial imaging module include multiple aperture and spiral wave imaging mode.

Embodiments may be directed to marine vibrators and associated methods that use appropriately selected composite code sequences. A method of seismic surveying may comprise operating a plurality of marine vibrators. At least one of the marine vibrators may repeatedly cycle through a plurality of composite code sequences that are unique to the at least one of the marine vibrators, wherein two or more of the marine vibrators operate contemporaneously for at least one output interval. The method may further comprise detecting seismic energy with one or more seismic sensors after the seismic energy has interacted with subsurface formations, wherein the seismic energy was emitted from the marine vibrators, wherein the detecting occurs while operating the plurality of marine vibrators.

There is taught herein a method of inducing micro fractures and fracture slip in formations thereby creating new dislocations in pre-existing fractures during hydraulic fracturing operations. An embodiment uses multi-component generated signals from multiple seismic signal generators located on or below the surface; and rotating the generated signals such that their vectors of propagation can be varied and optimized for inducing the micro-seismic and fracture slip events for highest cumulative hydrocarbon extraction considering the mechanical properties and direction of the stresses and pre-existing fractures. Embodiments relate to methods for inducing additional seismic events and fracture slip during hydraulic fracturing, particularly micro-seismic events and fracture slip which improve the short and long term production from the reservoir formation. More specifically, but not by way of limitation, embodiments of the present invention relate to such methods for inducing and optimizing the events in the target reservoir formation.

Methods and devices for imaging wells using ultrasound is described. The devices include a modular imaging device having a telemetry module and a radial imaging module and/or forward imaging module. The radial imaging module includes a ring shaped phased array ultrasonic transducer array for generating images on the length of a wellbore. Various lens and housing configurations for the radial imaging module are described. The forward imaging module includes an ultrasonic transducer comprising one or more elements and having an adjustable viewpoint for generating images of obstructions found in a wellbore. Advanced imaging modes for a radial imaging module include multiple aperture and spiral wave imaging mode.

Method, source array and seismic vibro-acoustic source element for seismic data acquisition. The method includes storing in a controller a library of beam form factor sets associated with a source array and corresponding regions to be surveyed; towing the source array along survey lines over the regions to be surveyed; selecting a beam form factor set from the library to be applied to the source array for each region; and actuating the source array based on the selected set of beam form factors and a position of the source array relative to the regions. Each set of beam form factors maps to a corresponding region of an area to be surveyed.