Abstract: The present invention relates to the field of marine towing operations for marine seismic survey systems and seismic data gathering. More specifically, the present invention relates to seismic sources and receiver sensor cables, streamers, floats etc., that have means for adjusting and keeping a desired position in an array during a tow behind a vessel. The apparatus comprises a pulley apparatus, being a kind of miming block (1), connected with and supporting marine equipment (3, 3?). The miming block (1) is configured to attach to the deflected lead wire or tow wire (2, 9). It has means for traveling along the wire (2, 9).

Abstract: The present invention relates to the field of marine towing operations for marine seismic survey systems and seismic data gathering. More specifically, the present invention relates to seismic sources and receiver sensor cables, streamers, floats etc., that have means for adjusting and keeping a desired position in an array during a tow behind a vessel. The apparatus comprises a pulley apparatus, being a kind of miming block (1), connected with and supporting marine equipment (3, 3?). The miming block (1) is configured to attach to the deflected lead wire or tow wire (2, 9). It has means for traveling along the wire (2, 9).

Abstract: The present invention relates to the field of marine towing operations for marine seismic survey systems and seismic data gathering. More specifically, the present invention relates to seismic sources and receiver sensor cables, streamers, floats etc., that have means for adjusting and keeping a desired position in an array during a tow behind a vessel. The apparatus comprises a body (10) with means for being towed behind a vessel, means for connecting with and supporting and steering submerged marine seismic equipment laterally in the water and means for remote control from vessel. The body (10) of the apparatus has a forward positioned float unit (16) with an elongated rear float (12) hinged at the rear of the forward float. The forward float unit has vertical wings (18, 18?) with means for adjusting angle of attack in water.

Abstract: The invention relates to a seismic streamer (1) for underwater towing at a towing speed in ice-free or wholly or partially icy water, the streamer (1) is provided with birds (2) spaced along the streamer, the streamer including the birds (2) has negative buoyancy, the birds have wings (8) which can be set so that the birds during movement in the water apply an upward or downward force on the streamer. The streamer (1) is provided with buoyant bodies (4) spaced along the streamer, the buoyant bodies are connected to the streamer by spacer elements (5), the streamer including the birds, the buoyant bodies with associated spacer elements and any other equipment together have positive buoyancy. The invention also relates to a corresponding method for securing a seismic streamer (1) from damage at a substantial reduction or cessation of towing speed when towing underwater in ice-free or wholly or partially icy water.

Abstract: A positioning system (100) for marine seismic surveying, comprising a towing vessel (110), a source array (120) and a receiver array (130) with several streamers (131). Each streamer (131) comprises at least three birds (134) and positioning sensors (134-137) wherein several seismic receivers (132) are placed between each pair of birds (134). The system (100) comprises a dynamic model wherein each streamer (131) is represented by a fitted B-spline curve and each bird (134) is associated with a constant velocity and a constant acceleration; and a Kalman filter using the dynamic model and observations from the positioning sensors (134-137) to provide a geodetic position of each seismic receiver (132) with better accuracy than the dynamic model alone and observations alone within a time interval ?t equal to or less than a minimum time between shots determined by the source array (120).

Abstract: The invention provides a system (100) for marine seismic surveying, comprising a towing vessel (110) with a controller, a source array (120) and a receiver array (130) with several streamers (131). The source array (120) comprises n>4 identical subarrays (121) configured as at least (n?1) seismic sources S1, . . . , Sn-1, wherein adjacent subarrays (121) are part of at least two sources Si, Sj at different times.

Abstract: The invention concerns a system (100) for detecting pollution (2) on or at a sea surface (3), wherein the system (100) is adapted for mounting on a marine vessel (1). The system comprises a detector (110) with a LIDAR for providing digital pollution data (112) relating to pollution (2) in a region (40) along a path (4) travelled by the marine vessel (1); a positioning system (120) for providing positioning data; a clock (131) for providing a digital timestamp; and a computer (130) for collecting, combining and storing digital data (141). The computer (130) is configured to execute a secure hashing algorithm (133) on pollution data (112) with associated positioning data and a timestamp to produce a digest, execute an encryption function (134) on the digest using a private key (sk) and to store the data (141) and encrypted digest (142) in a database (140).

Abstract: A cable fairing (fairing) (40) for reducing the flow resistance for a cable (45) has a wing formed cross section with a wide, rounded front and a tapered tail, a through-going cable channel (46) for the cable (45) perpendicular to the cross section of the widest part of the cross section. The wing profile comprises an elastic material of sufficient stiffness to maintain the shape when it is towed thereby causing flow resistance. The cable fairing (40) has slots (42) cut into the elastic material from the tail towards the cable channel (46), so that the tail comprises slats (41) which can be bent parallel to the cable channel (46) to reduce the cross-section of the cable fairing. By this is low flow resistance, as from a stiff cable jacket, combined with sufficient elastic deformability so the cable (45) with attached cable fairings (40), can be winched and pass through narrow openings in the deployment and retrieval, and wound onto a reel for storage and transport.

Abstract: A cable fairing (fairing) (40) for reducing the flow resistance for a cable (45) has a wing formed cross section with a wide, rounded front and a tapered tail, a through-going cable channel (46) for the cable (45) perpendicular to the cross section of the widest part of the cross section. The wing profile comprises an elastic material of sufficient stiffness to maintain the shape when it is towed thereby causing flow resistance. The cable fairing (40) has slots (42) cut into the elastic material from the tail towards the cable channel (46), so that the tail comprises slats (41) which can be bent parallel to the cable channel (46) to reduce the cross-section of the cable fairing. By this is low flow resistance, as from a stiff cable jacket, combined with sufficient elastic deformability so the cable (45) with attached cable fairings (40), can be winched and pass through narrow openings in the deployment and retrieval, and wound onto a reel for storage and transport.

Abstract: The invention relates to a seismic streamer (1) for underwater towing at a towing speed in ice-free or wholly or partially icy water, the streamer (1) is provided with birds (2) spaced along the streamer, the streamer including the birds (2) has negative buoyancy, the birds have wings (8) which can be set so that the birds during movement in the water apply an upward or downward force on the streamer. The streamer (1) is provided with buoyant bodies (4) spaced along the streamer, the buoyant bodies are connected to the streamer by spacer elements (5), the streamer including the birds, the buoyant bodies with associated spacer elements and any other equipment together have positive buoyancy. The invention also relates to a corresponding method for securing a seismic streamer (1) from damage at a substantial reduction or cessation of towing speed when towing underwater in ice-free or wholly or partially icy water.

Abstract: A bend stiffener to surround an end portion of an elongated, essentially cylindrical object, e.g. a flexible pipe or a cable, extending from a subsea installation to a surface vessel, and is connected to an end piece or end flange of the object at a connection to the vessel. A plurality of spaced apart clamp sets, each set has inner, essentially cylindrical clamp surrounding the object and semi-circular longitudinal grooves for receiving spring rods in an outer surface thereof, and outer clamp which in inner surface thereof has longitudinal semi-circular grooves for receiving the spring rods. The spring rods are secured in the end piece or the end flange or an adapted arrangement on the object. Each outer clamp is secured to the respective inner clamp and locks the spring rods relative to the inner clamp and the object.

Abstract: A system for towing equipment at sea comprises a main vessel adapted to tow the equipment in a given direction of movement. At least one active deflector is disposed behind and on each side of the main vessel for pulling at least part of the towed equipment transversely in relation to the direction of movement of the main vessel. At least one support vessel is connected to each deflector for assisting the deflector in pulling at least part of the towed equipment transversely in relation to the direction of movement of the main vessel, and for assisting the main vessel by providing additional towing force to the towed equipment. The additional towing force provided by the support vessel is essentially parallel in direction to the force provided by the main vessel. A cable connects each support vessel to the associated active deflector for supplying one or more of power and control signals from the support vessel to the associated deflector. At least one wing is attached to each deflector.

Abstract: A deflector for towing behind a vessel, especially for use in relation to seismic surveys, being adapted to pull equipment to a transversal position in relation to the moving direction of the vessel, comprising at least one connection point for connecting, through wires or similar, to the vessel and the equipment to be towed. Two or more deflector wings are adapted to provide the deflector with a lifting force transversally in relation to the moving direction of the vessel, at least one of the wings being provided with a rotating cylinder positioned in front of the wing adapted to increase the lift of the deflector wing, and a drive unit for driving the rotating cylinder with corresponding devices for power supply.