Abstract A neutrally buoyant seismic hydrophone streamer is constructed by extruding a syntactic foam material comprising an elastomeric material and gas filled microspheres onto a central stress member to form an elongated streamer member. The streamer may then be covered with a suitable water and oil resistant, abrasion resistant covering and be provided with exteriorly affixed hydrophones, or hydrophones can be affixed to the foam core and an outer protective sheath can be extruded or otherwise provided around the streamer and the hydrophones to provide a uniform diameter streamer assembly. Extrusion is effected utilizing a suitable elastoplastic material which can be extruded at temperatures below about 300 psi to avoid bursting the gas filled spheres of the syntactic foam.
The streamer of claim 1 wherein said thermoplastic resin is a linear urethane polymer of methylene bis-4-phenyldiisocyanate and polytetramethylene ether glycol.
Claim 2
Dependent Claim
33 words
The streamer of claim 1 including signal wires extending from said transducers disposed around said central stress member, and wherein said extruded layer surrounds said stress member, said signal wires and said transducers.
Claim 3
Dependent Claim
38 words
The streamer of claim 1 wherein said transducers are disposed in recesses in the syntactic foam portion of said extrudate to define a structure wherein the diameter of said transducers corresponds essentially to the diameter of said extrudate.
Claim 4
Dependent Claim
22 words
The streamer of claim 1 adapted for use in static arrays wherein said transducers are affixed to the exterior of said sheath.
Claim 5
Dependent Claim
21 words
The streamer of claim 1 wherein said outer sheath is substantially free of stress bearing members extending longitudinally of said streamer.
Claim 6
Dependent Claim
23 words
The streamer cable of claim 1 wherein said microparticles are glass microspheres having a size of from about 25 to about 300 microns.