A marine seismic source includes source elements configured to emit waves having different frequencies while the source elements are towed at different predetermined depths, respectively. The predetermined depths are calculated such that water-surface reflections of the waves generated by a source element among the source elements interfere constructively with the waves generated by the source element and propagating toward an explored structure under the seafloor. The waves combine to yield a spike-like signature of the source.

A seismic detection line includes one or more identified element(s) arranged in a string, and a telemetry link connecting the element(s) along the string to convey seismic data from at least one of the element(s) to a data recorder and identification data to a topology controller. Each of the element(s) includes a respective first identification unit connected to the telemetry link to provide a respective first identifier to the topology controller. A seismic detection system also includes a processor that queries the identified element(s) for their respective identifiers, determines an arrangement of the seismic detection line using the received identifiers, and presents an indication of the determined arrangement. A method of operating a seismic detection line includes transmitting a query along the telemetry link, detecting whether the respective identifier of one of the element(s) was received or not, repeating until termination, and determining and indicating the arrangement.

A system includes an unmanned marine vessel having a hull; a multi-dimensional seismic sensor array coupled with the hull, wherein the multi-dimensional seismic sensor array is configured to acquire seismic survey data in multiple directions; wherein the unmanned marine vessel comprises a power source configured to drive and provide propulsion to the unmanned marine vessel; and an umbilical cord for coupling the multi-dimensional seismic sensor array with the hull of the unmanned marine vessel, wherein the umbilical provides electrical communication between the unmanned marine vessel and the multi-dimensional seismic sensor array.

Acoustic source arrays and related methods. At least some of the example embodiments are methods including towing a first source sub-array comprising a first surface float, the first surface float defines a first connection point at a proximal end of the first surface float. The method may further include towing a second source sub-array comprising a second surface float, the second surface float defines a second connection point at a proximal end of the second surface float. And during the towing of the first and second source sub-arrays, the method may include maintaining a lateral separation between the first and second connection points of the first and second surface floats by a first strut, the first strut coupled between the first connection point of the first surface float and the second connection point of the second surface float.

Systems and methods for acquiring blended and unblended seismic data during a single seismic survey. The blended and unblended seismic data is generated with a plurality of sources that are fired in a dedicated sequence. The sequence involves firing all the sources at a first time, advancing the sources along a given path, firing only a first source at a second time, later than the first time, advancing the sources, firing again all the sources at a third time, later than the second time, advancing the sources, firing only a second source at a fourth time, later than the third time, and so on until a desired subsurface is fully surveyed.

A seismic acquisition system for acquiring seismic data includes a streamer spread including first and second streamers, each of the first and second streamers having at least one seismic receiver and at least one position control device, and a seismic source located within an area underlined by the streamer spread and configured to generate seismic waves. The streamer spread and the source are towed independent of each other, a streamer separation DS between the first and second streamers varies along a length of the spread to comply with a given survey characteristic, and the streamer separation varies from a front-end value DS(F) at a front-end of the spread, to a middle of the spread value DS(O), to a back-end value DS(B) at a back-end of the spread, and the middle of the spread value is smaller than the front-end value and smaller than the back-end value.

The present disclosure is directed to a skid structure for underwater seismic exploration. The system can include an underwater vehicle comprising a skid structure. A conveyor is provided in the skid structure. The conveyor includes a first end and a second end opposite the first end. A capture appliance is provided at the first end of the conveyor. The capture appliance includes an arm to close to hold a case storing one or more ocean bottom seismometer (“OBS”) units, and to open to release the case. The capture appliance includes an alignment mechanism to align an opening of the case with the first end of the conveyor. A deployment appliance can be at the second end of the conveyor. The deployment appliance can place an OBS unit of the one or more OBS units onto the seabed to acquire seismic data from the seabed.

The present disclosure is directed to underwater seismic exploration with a helical conveyor and skid structure. The system can include an underwater vehicle comprising a sensor to identify a case having a hydrodynamic shape, wherein the case stores one or more ocean bottom seismometer (“OBS”) units. The underwater vehicle includes an arm. The underwater vehicle includes an actuator to position the arm in an open state above a cap of the case, or to close the arm. The underwater vehicle can move the arm to a bottom portion of the case opposite the cap. An opening of the case can be aligned with the conveyor of the underwater vehicle. The conveyor can receive, via the opening of the case, a first OBS unit of the one or more OBS units. The conveyor can move the first OBS unit to the seabed to acquire seismic data from the seabed.

The methods and devices described herein provide a sensor array positioning system that may allow a user to program a series of sensor array locations, depths and orientations into a control center, which therein commands an unmanned surface or submarine vehicle which positions a sensor array. The devices comprise of an unmanned vehicle using less than about 20 Watts of power, a tow cables, a flexible sensor array comprising one or more sensors, one or more floats and one or more weights.

A seismic apparatus includes one or more seismic cable systems configured to acquire seismic data, each seismic cable system having one or more of a cable jacket, a reservoir for a ballast fluid or other ballast medium, and an actuator or other transfer mechanism configured to transfer the ballast fluid between the reservoir and the seismic cable system during acquisition of the seismic data, e.g., where the ballast fluid is transferred to the seismic cable system within the cable jacket. A controller can be configured to adjust a buoyancy of the seismic cable system responsive to the transfer of the ballast fluid, e.g., where the internal volume expands or contract based on the fluid transfer.