Abstract:
A seismic marine streamer (10) including hydrophones (12) housed in elongate flexible tubes (11), a pair of load carrying rope members (25, 26), and a plurality of spacers (15) which substantially fill the internal cross-section of the tube (11), the internal void within the tube being filled by a liquid, the two rope carrying members (25, 26) interconnect end fittings (21, 22) located one at each end of a tube (11) and passing through each spacer (15) on diametrically opposite sides thereof.
Abstract:
A device connected to an underwater cable by means of a sacrificial latch mechanism that breaks to protect the housing of the device from irreparable damage due to collisions with jetsam or other objects. The underwater device is connected to a cable having mounting elements disposed along its length. The device includes a housing and a latch body attached to the housing by a retainer, such as a set screw. A locking member extends from the latch body to engage the mounting element. A sacrificial element, such as a thin portion of the latch body or a frangible portion of the retainer, gives way in response to a predetermined force acting to separate the device from the cable before the force can damage the housing.
Abstract:
An improved bottom cable for a seismic marine data acquisition system 10. The bottom cable 30 includes a cable section 30b having a bus 48. The cable, along with the cable section and bus, are used to electrically connect a master control unit 40 to first and second modules 32b and 32c, respectively. The bus 48 includes first and second switches 48b and 48c, respectively, located near opposite ends of the bus. In this way, if a leak R1 occurs in the bus, the first and second switches can be opened, thereby electrically isolating the bus and stopping the leak.
Abstract:
At least one vibration isolation module (VIM) and at least one acoustic sor module of an elongate array are uniquely accommodated by a continuously extending, hose-shaped strength member dimensioned to define a space for noncompressively containing the acoustic sensor module and allow responsive sensing. The strength member has a nonelastic first portion to contain the length of the acoustic sensor module and includes a plurality of longitudinally extending juxtaposed cords. The cords are held in an equidistantly spaced side-by-side relationship by an appropriate fill-weave that assures sufficient flexibility. A coextensive portion of the strength member is fabricated from the plurality of longitudinally continuously extending juxtaposed cords to extend in an exaggerated sine wave configuration throughout the length of the VIM. A plurality of elastic warp bogies are disposed in-between the cords and are held in a side-by-side relationship by substantially the same appropriate fill-weave. The elastic warp bogies and sine wave configuration of the cords allow the strength member to be longitudinally stretched as it bears the array's dynamic drag. Increased loads can stretch the elastic warp bogies to a maximum length to where the cords carry any additional load. Opposite ends of the coextensive portion of the strength member are secured to the elastic sheath for load sharing with the sheath. Optionally, the VIM could be separate to accommodate existing arrays or other vibration isolation applications.
Abstract:
A hydrophone array to perform passive and active sound imaging is described. The array is comprised of a plurality of acoustic transducers attached to a cable that may be towed behind a geophysical survey vessel. The cable and acoustic transducers are enclosed within a sheath of essentially constant external dimensions, which extends longitudinally the length of the cable and which is effective in minimizing turbulent noise created by the array during its use. The sheath may be circular or elliptical in cross-section and can enclose a jacket of resiliently flexible and positively buoyant material that encases the cable and transducers.
Abstract:
An impervious cable connected electrical component assembly is provided wh includes an electrical component which has a conductive wire extending therefrom. An impervious container is provided which has an open top and a closed bottom. The electrical component is located within the container with its conductive wire extending out of and beyond the container's top. A cable is provided which has a conductive wire within an impervious sheath. A lengthwise portion of this wire is exposed. The conductive wire extending from the top of the container and the exposed conductive wire portion of the cable are electrically joined at a junction outside the container. An impervious sleeve is bonded to the cable sheath so as to hermetically seal the wire junction along the cable. The open top of the container and the sleeve are bonded to hermetically seal the electrical component. With this arrangement the assembly can be easily constructed with minimal effect on the electrical component and, after construction, the assembly can be used with maximum protection of the electrical component.
Abstract:
A hydrophone module for a towed hydrophone array. The module comprises: (1) an elongated hydrophone module housing having a desired hydrophone group center associated therewith and (2) a plurality of hydrophone elements located substantially aperiodically along a length of the housing and electrically coupled together in a hydrophone group, the hydrophone group having an actual hydrophone group center proximate the desired hydrophone group center to thereby allow locations of the plurality of hydrophone elements to be altered without dislocating the actual hydrophone group center. Individual hydrophone elements within the group may therefore be moved within the module without disturbing the actual hydrophone group center.
Abstract:
Disclosed is a vibration isolation module for a towed hydrophone streamer comprising: (1) a first transition unit, an outboard end of the first transition unit capable of receiving a first tension member, the first tension member terminating within the first transition unit, an inboard end of the first transition unit capable of receiving second and third tension members, the second tension member entering, looping back and exiting the inboard end of the first transition unit, the third tension member terminating within the first transition unit and (2) a second transition unit, an outboard end of the second transition unit capable of receiving a fourth tension member, the fourth tension member terminating within the second transition unit, an inboard end of the second transition unit capable of receiving the second and third tension members, the second tension member entering, looping back and exiting the inboard end of the second transition unit, the third tension member terminating within the second transition unit.
Abstract:
A towed streamer including buoyant core (1), and strength members (3) to transmit tension along the streamer. Strength members (3) are arranged so that the streamer is compliant for a predetermined elongation of the streamer. Members (3) are embedded in an inner jacket (5) surrounded by an outer jacket (6). The assembly is encased in an extruded outer jacket (2). Braided data bearers (4) can be provided between the inner jackets (5, 6). Strength members (3) can be braided with interstices impregnated with gel. Where the strength members (3) are of non-compliant material, the braid is initially compliant where the streamer is slightly elongated but becomes non-compliant as the streamer elongates further. Alternatively a combination of compliant (3) and non-compliant members (14) can be used where the compliant members (3) only become engaged after a predetermined elongation of the streamer.
Abstract:
This invention discloses a method and apparatus for waterblocking wire-to-wire connections in a cable using an arrangement of seals. Lead-in transmission lines are slid through a multiple-aperture seal to produce a compression seal between the transmission lines and the seal and the trailing transmission line is slid through a single-aperture seal to produce another compression seal. A piece of constrictive tubing is slid over the first seal before splicing the wires in the lead-in and trailing transmission lines together. The tubing then is positioned over both seals to produce a compression seal between the tubing and the seals to form a waterblock in the area defined by the two seals containing the splice.