Optoplan As

Weatherford/lamb, Inc.

Invivosense Asa

Alcatel Submarine Networks

Optomed. As

Stiftelsen for Industriell Og Teknisk Forskning Ved Norges Tekniske

Arne Berg

Sverre Knudsen

Roar Furuhaug

Ole Henrik Waagaard

Hilde Nakstad

Jon Thomas Kringlebotn

James R Dunphy

Erlend Rønnekleiv

Tormod Bliksås

Daniel M Woo

Erlend Ronnekleiv

Reinold Ellingsen

Torbjørn Heglum

Dag Roar Hjelme

Berit Falch

Astrid Bjørkøy

Dan Østling

Torbjoern Heglum

Robert Joe Coon

Francis X Bostick, Iii

Michael J Foster

Daniel Ming Kwong Woo

Paul Travis

Dag Thingb&oslash;

Torbjøm Heglum

Torbjorn Heglum

Geir Bjarte Havsgard

Lars Inge Hofstad

Dag Roar Hjeime

Kevin S Kippola

Tormod Bliks{dot Over (a)}s

Torbjoern Helgum

Sverre Knudson

A fibre-optic hydrophone comprising a substantially incompressible tubular body, the tubular body generally having a geometry of a cylindrical shell defining an axis, and a deflectable outer wall, arranged to surround the tubular body in a distance thereof, and defining an axis that is arranged to substantially coincide with the axis of the tubular body. The hydrophone further comprising an optical fibre coil arranged on an outer surface of the outer wall, and a first and a second end lid arranged to seal the tubular body and the outer wall at a first end and a second end thereof, respectively, the first end lid and the second end lid being substantially incompressible. Additionally, the hydrophone comprising an outer cavity defined by an inner surface of the outer wall, an outer surface of the tubular body, the first lid, and the second lid; and an inner cavity defined by an inner surface of the tubular body, the first lid, and the second lid. The outer cavity is in fluid communication with the inner cavity via one or more passages in the tubular body, the outer cavity and the inner cavity being filled with a fluid, wherein the passages are configured to contribute to a function as a filter defining a low pass filter response with high cut-off frequency. In some embodiments the deflectable outer wall is cylindrical.

Fibre-optic hydrophone with internal filter

A subsea installation tool for installing a flexible body, e.g. a subsea fiber cable on a seabed from a surface vessel, and an associated method for installing the flexible body on the seabed is provided. The installation tool includes a tensioner that may be coupled to the flexible body to actively pull it down, thus increasing tension in an upper section of the cable from the installation vessel to the installation tool. High tension in the upper part of the cable gives good control even in strong sea currents. At the same time the tensioner enables lower tension in the bottom part cable from the installation tool to the seabed, giving good control of the touchdown position on the seabed.

Subsea cable installation unit

There is provided a solid seismic streamer cable for use in seismic surveying in marine environments. The streamer is characterized by a buffer layerwhich is provided with a cut-outand a sensor element arranged in the cut-out. There is also provided an associated hydrophone for integration into the seismic streamer cable. The hydrophone is characteristic in a split-element sensor basebeing suited for efficient mounting into the cut-outsof the seismic cable. There is also provided an associated accelerometer for integration into the seismic streamer cable. The accelerometer is characteristic by a split-element sensor basefor being efficiently arranged into the cut-outsof the seismic cable. A method of producing a seismic streamer cable according to the invention incorporating a hydrophone or accelerometer according to the invention is also provided.

Method of producing a seismic streamer cable

Methods and apparatus for cable termination and sensor integration at a sensor station within an ocean bottom seismic (OBS) cable array are disclosed. The sensor stations include a housing for various sensor components. Additionally, the sensor stations can accommodate an excess length of any data transmission members which may not be cut at the sensor station while enabling connection of one or more cut data transmission members with the sensor components. The sensor stations further manage any strength elements of the cable array.

Ocean bottom seismic station

A rotary joint or swivel device for ensuring a continuous connection between two items that rotates with respect to each other, for example between an instrumentation unit on a fixed installation and sensor elements in a cable on a rotating cable reel or drum, is provided. The rotary joint or swivel device comprises a minimum of two spoolsto coil a connecting cable. A first spoolis coupled to a first, static, item. A second spoolis coupled to a second, rotatable, item. A guiding armfeeds the connecting cablefrom the firstto the secondspool. Correspondingly, a method for ensuring a continuous connection between two itemsthat rotates with respect to each other is provided. The method comprises arranging a rotary joint or swivel device according to any of the embodiments of the invention between the two items.

Rotary joint/swivel device

There is provided a solid seismic streamer cable for use in seismic surveying in marine environments. The streamer is characterized by a buffer layerwhich is provided with a cut-outand a sensor element arranged in the cut-outThere is also provided an associated hydrophone for integration into the seismic streamer cable. The hydrophone is characteristic in a split-element sensor basebeing suited for efficient mounting into the cut-outsof the seismic cable. There is also provided an associated accelerometer for integration into the seismic streamer cable. The accelerometer is characteristic by a split-element sensor basefor being efficiently arranged into the cut-outsof the seismic cable. A method of producing a seismic streamer cable according to the invention incorporating a hydrophone or accelerometer according to the invention is also provided.

Split-element optical hydrophone

Seismic sensor systems and sensor station topologies, as well as corresponding cable and sensor station components, manufacturing and deployment techniques are provided. For some embodiments, networks of optical ocean bottom seismic (OBS) stations are provided, in which sensor stations are efficiently deployed in a modular fashion as series of array cable modules deployed along a multi-fiber cable.

Seismic streamer array

Connector nodes for interrogating optical fiber sensor arrays

Bi-directional interrogation of optical sensors

A dome-shaped chemical sensing probe comprises an optical fiber or may be mounted on an optical fiber. The probe has a chemically sensitive measuring material which exhibits a change in volume and/or a change in refractive index in the presence of a given chemical. The change in volume and/or refractive index gives a change in an optical path length through the probe which can be measured interferometrically.

Optical sensing of measurands

A seismic sensor station includes a housing containing a fiber optic hydrophone and a fiber optic accelerometer that can both be made from a single length of optical fiber arranged inside the housing. The fiber optic accelerometer is arranged in a liquid/oil filled compartment of the housing for dampening of mechanical resonances in the accelerometer due to mechanical disturbances and pressure fluctuations.

Seabed seismic station packaging

Growing community of inventors

Kattem, Norway

Arne Berg