Geco A.s.

Einar Gjestrum

Jan-Age Langeland

Oyvind Sorbotten

Clive T Snook

Rolf Bjerkoy

Julius Bendiksen

Gunnar F Valle

Tormod Skifjeld

Rolf Bjerk Y

Oyvind Hogsnes

Michael Russell

Lars Knudsen

Oddbjorn Hjelle

Device for handling of cables on seismic vessels

Release device for a cable used during seismic surveys at sea and towed through the water behind a vessel so that in the event of the occurrence of obstacles or other occasions when it is desirable to release the cable (1) from the towing vessel, a controlled release of the cable is possible so that it is not severed, but can be recovered for further use. At one or more locations in such cables release sections (2) are inserted which contain sensors which sense loading in the section and in the event of overloading or other occasions when release is desirable, an element (5) is activated which cause a release mechanism (6) to be activated and thereby causes a split in the cable (1) at a predetermined location.

Method and apparatus for release of a seismic array, especially

A bouyancy towed body, especially to be used in marine seismic surveys is assembled from a plurality of modules (1, 2, 3, 4) for adaption to various applications. Modules (1-4) may be locked together, e.g. by through rods (6) provided with tensioning screw and nut devices (8). Modules (1-4) are assembled to form a buoyancy member having a homogeneous surface shape. One (3) or a plurality of modules may be provided with elements (5) for attaching desired equipment thereto which may hang down from the towed body.

Arrangement in a buoyancy towed body means

A fastening device for fixing seismic circular devices is designed with a rigid, split, annular clamp (4) with an open void facing the seismic device (1) for insertion of at least one shock absorbing member (7) in the void. Such a clamp (4) is provided in the region of the device which is most subjected to strain, where a concentric securing ring (8) is also mounted, about which the clamp is fitted with a shock absorbing member (7) on each side of the ring. One more such clamp is provided on the seismic device (1) in order to distribute the load. This arrangement is especially suitable for use in connection with seismic airguns which are to be fixed at predetermined mutual distances in a frame structure (2).

Fastening means for seismic equipment

A cable handling apparatus draws in a cable, such as a seismic streamer, along a generally linear path and feeds the cable to a winch which winds in the cable from the apparatus under constant tension.

Cable handling apparatus

An arrangement for deployment and towing of a plurality of seismic cables (2) in parallel and at a mutual distance behind a vessel whereby seismic cables (2) are wound on winch barrels (4), and are provided with an inner cable member (3) which forms a connection with the vessel (1) during a towing operations, and is, additionally, provided with a paravane/control (14, 15) to guide and maintain the cable (2) laterally in relation to the towing vessel (1). Reliable and simple depolyment and towing of the seismic cables (2) at a large distance laterally in relation to the center line of the vessel is achieved by running the inner cable member (3) through at least one guide pulley (5) suspended from a line (7) that is adjustable in length from the vessel, and is, preferably extended over a derrick device (9) projecting from the vessel. Guide pulley (5) can be hauled in and paid out from the vessel, at the same time as inner cable member (3) can be let out to a greater length from the vessel.

Arrangement for deployment of seismic cables

An angular member provided on seismic cables towed by a vessel and laterally displaced in parallel and in relation to the course of the vessel comprises a frame at least partly enclosing the cable in the area of angular deflection between an inner cable portion extending obliquely to the towing direction and the active main cable portion. The frame is formed of two frame plates secured in spaced relationship and having at the lead-in end for the cable a cable-fastening device and at the other end a pivotable ramp swingable in the plane of the frame plates. The ramp has a further fastening device for the cable. Another fastening device is pivotably connected to the frame plates for connecting thereto a wire to a paravane or the like. When towed in the water the angular member absorbs most of the forces normally exerted on the cable at the area of angular deflection.

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Sandvika, Norway

Einar Gjestrum