Sensors used in mapping strata beneath a marine body are described, such as used in a flexible towed array. A first sensor is a motion sensor including a conductive liquid in a chamber between a rigid tube and a piezoelectric motion film circumferentially wrapped about the tube. A second sensor is a traditional acoustic sensor or a novel acoustic sensor using a piezoelectric sensor mounted with a thin film separation layer of flexible microspheres on a rigid substrate. Additional non-acoustic sensors are optionally mounted on the rigid substrate for generation of output used to reduce noise observed by the acoustic sensors. Combinations of acoustic, non-acoustic, and motion sensors co-located in rigid streamer housing sections are provided.

Embodiments relate generally to marine geophysical surveying. More particularly, embodiments relate to an underwater application system for application of a streamer coating to a surface of a streamer. An embodiment may comprise a marine geophysical survey system. The marine geophysical survey system may comprise a streamer and an underwater application system operable to apply a streamer coating to the streamer as the underwater application system travels axially along the streamer.

The present invention provides a five-component marine natural gas hydrate intelligent sensing node, comprising a titanium alloy compartment, an information acquisition unit, an integrated control chip, and a power module; the integrated control chip comprises an intelligent computing unit and a transmission unit; the intelligent computing unit is configured for acquiring quality monitoring indicators of marine natural gas hydrates by feature extraction and transmitting reduced represented features to a monitoring device on the sea surface via the transmission unit. The present invention has overcome problems of impossible timely quality monitoring due to blind acquisition process, promised a controllable undersea node working status, and acquired data are complete without any loss, which doesn't only facilitate nonconventional energy resources such as marine hydrates prospection, and is also of great application prospect and value in oil and gas resources exploration, geological hazards precautions and evaluation.

Disclosed is a combined submarine seismic acquisition node with a secondary positioning function, including an ocean bottom node connected with an external loading ship; a protective sleeve circumferentially covering outside the ocean bottom node; and response components fixed inside the ocean bottom node, and the response components are configured to send position information of the ocean bottom node, and the response components may perform an information interaction with the loading ship.

Apparatus and techniques are disclosed relating to sensor housing and spacer carrier assemblies. In various embodiments, a spacer carrier provides a cavity through a body of the spacer carrier and a first alignment element positioned at a first end of the cavity. In some embodiments, a sensor housing is configured to be deployed within the cavity through the body of the spacer carrier. The sensor housing may include a housing body configured to receive a sensor and a second alignment element configured to interface with the first alignment element. In various embodiments, the first and second alignment elements are configured to maintain an orientation of the sensor housing within the cavity when the sensor housing is inserted into the spacer carrier.

Disclosed is a non-steel strength membered high strength cable easily monitored for heat and elongation comprising a length of a core-cable (10), the length of core-cable (10) including at least two fiber-optic conductors (2) that are: (i) disposed in a helical shape; and (ii) completely encased in a solid, flexible material.
One fiber-optic conductor capable of transmitting at least Raman backscattering and the other fiber-optic conductor capable of transmitting at least Brillouin scattering.

A combination of the cable (10): (i) with an interrogator that can read and interpret Raman backscattering coupled to and communicating with the fiber optic conductor that is capable of transmitting at least Raman backscattering; and (ii) another interrogator that can read and interpret Brillouin scattering coupled to and communicating with the fiber optic conductor that is capable of transmitting at least Brillouin scattering;
permits ascertaining the elongation of the cable, without using loose tube fiber-opticplacement.

A seismic sensor stake, system and method configured to orientate three seismic 1C sensors orthogonally in the X, Y, and Z directions. The present technology stake is configured to efficiently and effectively convert three independent seismic sensors into a single three seismic sensor unit. Multiple stakes can be inserted into the ground of a geographical area to provide highly accurate seismic survey of subterranean hydrocarbon formations. Each seismic sensor can include a slot that slidable receives a threaded member of a mounting sides of the stake. A retaining nut can secure the seismic sensor in place upon rotation of the sensor. A stake bit can be utilized with an impact hammer to form holes in hard or frozen ground for quick insertion of the stake into the ground.

A seismic sensor stake, system and method configured to orientate three seismic 1C sensors orthogonally in the X, Y, and Z directions. The present technology stake is configured to efficiently and effectively convert three independent seismic sensors into a single three seismic sensor unit. Multiple stakes can be inserted into the ground of a geographical area to provide highly accurate seismic survey of subterranean hydrocarbon formations. Each seismic sensor can include a slot that slidable receives a threaded member of a mounting sides of the stake. A retaining nut can secure the seismic sensor in place upon rotation of the sensor. A stake bit can be utilized with an impact hammer to form holes in hard or frozen ground for quick insertion of the stake into the ground.

Various embodiments include apparatus and methods implemented to take into consideration gauge length in optical measurements. In an embodiment, systems and methods are implemented to interrogate an optical fiber disposed in a wellbore, where the optical fiber is subjected to seismic waves, and to generate a seismic wavefield free of gauge length effect and/or to generate a prediction of a seismic wavefield of arbitrary gauge length, based on attenuation factors of a plurality of wavefields acquired from interrogating the optical fiber. In an embodiment, systems and methods are implemented to interrogate an optical fiber disposed in a wellbore, where the optical fiber is subjected to seismic waves, and to convert a seismic wavefield associated with a first gauge length to a seismic wavefield associated with a different gauge length that is a multiple of the first gauge length. Additional apparatus, systems, and methods are disclosed.

A method for calculating a velocity vp(f, T.sub.opt) of a spatially aliased wave that propagates along a cable includes tensioning the cable, wherein plural sensors are distributed along the cable; measuring with the plural sensors a parameter that is associated with vibrations that propagate along the cable; calculating a phase velocity vp(f) of the spatially aliased wave that propagates along the cable, as a function of a time frequency fin a spatial-temporal frequency domain FK; calculating a model-based velocity vp(f, T) of the spatially aliased wave as a function of the time frequency f and a tension T in the cable; and calculating the velocity vp(f, T.sub.opt) of the spatially aliased wave using a model-guided regression, which is based on the phase velocity vp(f) and the model-based velocity vp(f, T). The velocity vp(f, T.sub.opt) is a function of the temporal frequency f.