Seismic wave sources for marine sites.

摘要

1,164,402. Combustion chambers operating under pressure. ESSO PRODUCTION RESEARCH CO. Jan. 11, 1968 [Feb. 6, 1967; June 5, 1967], No. 1602/68. Heading F1L. [Also in Division H4] A seismic wave source for marine use, of the type in which a combustible fluid is detonated in an expansible chamber, is provided with a passage through which fluid-flows to cool the detonation products. In the Fig. 15 embodiment the chamber is defined by an elastic sheath 61 (e.g. of rubber or neoprene) clamped at 44, 62 to cup-shaped members 75, 63. A cylindrical assembly of parallel metal tubes 51 supports sheath 61, the tube outer walls being sealed to members 75, 63. When the source is towed through the water, water flows between member 75 and a coaxial cupshaped member 77, flows through tubes 51, and emerges from member 63. An oxygen/propane or oxygen/acetylene mixture, introduced via hoses 19, 21, check valves 37, 39 and mixing chamber 41A into member 77 is detonated by spark plug 50 to inflate sheath 61 and thereby generate seismic waves. An exhaust valve 45 comprising a closure member spring-loaded against a seat vents combustion products to the atmosphere via hose 27, the closure member being of high inertia to allow sheath 61 to expand appreciably before venting occurs. The supply of combustible gases and the energizing of spark plug 50 are synchronized with the operation of a seismic wave recorder. Alternative embodiments, in which the number of cooling tubes 51 and the shape of the combustion chamber are modified, are described and details are given of towing arrangements for the source.