US3670839A - Extended area acoustic impulse generator - Google Patents

Extended area acoustic impulse generator Download PDF

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Publication number
US3670839A
US3670839A US844152A US3670839DA US3670839A US 3670839 A US3670839 A US 3670839A US 844152 A US844152 A US 844152A US 3670839D A US3670839D A US 3670839DA US 3670839 A US3670839 A US 3670839A
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United States
Prior art keywords
wall
liquid body
generator
acoustic impulse
chamber
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Expired - Lifetime
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US844152A
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English (en)
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Carl H Savit
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Western Atlas International Inc
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Western Geophysical Company of America
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
    • G01V1/00—Seismology; Seismic or acoustic prospecting or detecting
    • G01V1/02—Generating seismic energy
    • G01V1/133—Generating seismic energy using fluidic driving means, e.g. highly pressurised fluids; using implosion
    • G01V1/135—Generating seismic energy using fluidic driving means, e.g. highly pressurised fluids; using implosion by deforming or displacing surfaces of enclosures, e.g. by hydraulically driven vibroseis™

Definitions

  • ABSTRACT An acoustic impulse generator for producing in a liquid body acoustic impulses useful, for example, in geophysical explorations.
  • the generator includes a housing which defines an enclosed chamber having a flexible wall.
  • Driving means in one operating condition cause the flexible wall to execute a forward stroke in the liquid body thereby storing potential energy in the liquid body.
  • the driving means in another operating condition allow the flexible wall to execute a return stroke in a relatively short time interval thereby generating an acoustic impulse.
  • U. S. Pat. No. 3,277,437 shows another type of acoustic generator submerged in a body of water which includes an enclosed chamber having a movable piston. Under the influence of a fluid-pressure-and-vacuum source the piston executes a forward stroke. The piston is then permitted to execute a return stroke thereby converting potential energy, stored in the liquid body during the forward stroke, into kinetic energy which makes available energy for the formation of an acoustic shock wave when the piston comes to rest. In this type of generator the acceleration of the piston during the return stroke is relatively limited.
  • a generator for generating high-power acoustic impulses when submerged in a liquid body.
  • the generator comprises a housing which defines an enclosed chamber having a flexible wall.
  • Driving means are coupled to the wall to cause the wall to execute a forward stroke in the liquid body.
  • potential energy is stored in the ambient liquid body.
  • the forward stroke may be relatively slow.
  • the potential energy stored in the liquid body is released upon command to cause the flexible wall to execute a return stroke in a relatively short time interval.
  • the flexible wall is elastic and if the wall is stretched in the course of the forward stroke, potential energy will also be stored in the wall; thus providing additional acceleration to the wall during the return stroke.
  • a cavity is then formed between the wall and the surrounding liquid body. The surrounding liquid rushes in to fill this cavity, and in so doing a high-power acoustic impulse becomes generated and propagated throughout the liquid body.
  • an acoustic impulse generator having a housing which defines a chamber having a flexible wall. Driving means are coupled to the flexible wall.
  • the driving means in one operating condiu'on cause the flexible wall to execute a forward stroke against the ambient pressure exerted by the liquid body and, if the wall is elastic, against the elastic resistance offered by the wall. As a result during the forward stroke potential energy is stored in the liquid body and in the wall, if elastic.
  • the driving means in another operating condition allow the wall to execute a return stroke.
  • the acceleration of the wall can be made sufficiently high to create a cavity between the liquid body and the wall, i.e., the wall during the return stroke can be made to move away from the liquid body-faster than the liquid can follow the wall.
  • the surrounding liquid th'en violently moves in to fill this cavity.
  • a portion of the kinetic energy of the moving in liquid becomes converted into acoustic energy in the form of a relatively high-level, lowfrequency pulse.
  • the violent collapse of this cavity produces an acoustic impulse which propagates throughout the liquid medium.
  • the surrounding liquid remains'in contact with the wall during the return stroke and produces an acoustic impulse when the wall abruptly comes to rest.
  • FIG. 1 shows in perspective a preferred embodiment of the extended area acoustic impulse generator of this invention
  • FIG. 2 is a view taken on line 2-2 of FIG. 1;
  • FIG. 3 is an enlarged detail view showing the manner of coupling the flexible wall
  • FIG. 4 shows another manner of coupling the flexible wall
  • FIG. 5 is a top view of another embodiment of this invention.
  • FIG. 6 is a view taken on line 6-6 in FIG. 5.
  • High-power, relatively low-frequency acoustic impulse generators or radiators for generating acoustic impulses in a liquid body, as in sea or ocean water, are particularly useful for seismic prospecting.
  • the acoustic impulses or signals of the greatest utility are those whose frequency lies in the range between 5 and 50 Hz or whose wave length in water lies between a thousand feet and feet. Consequently, most seismic impulse generators or radiators are, because of logistic considerations, small compared to a wave length.
  • the radiated acoustic power will be proportional to the product of the area and the distance traveled by the radiating surface.
  • the generator will produce on the order of 16 times as much far field acoustic energy as a generator whose dimensions of the radiating surface are 2% by 2% feet and whose stroke is 16 inches. Both such generators would requ'ue the same input energy.
  • FIGS. 1 through 3 there is shown an extended area acoustic impulse generator generally designated as 10.
  • Generator 10 is shown completely submerged to a given depth in a liquid body such as sea water 12.
  • the depth below the air/water interface at which generator 10 is positioned is sometimes herein referred to as the operating depth characterized by an operating ambient hydrostatic pressure.
  • Generator 10 may assume various geometric configurations.
  • the generator I defines a chamber 14 having a flexible wall 16 fixedly and sealingly coupled to a rigid anvil wall 18, as by bolts 20 fastened to a retaining ring 22.
  • Anvil 18 is preferably made of metal and the selection of its linear dimensions are determined by the design criteria above described.
  • the edges of anvil 18 have a relatively greater thickness dimension than its center portion to add greater rigidity to the structure of generator 10 and to allow a greater displacement or stroke for the flexible wall 16.
  • Wall 16 may be made of a suitable flexible material which may be a reinforced plastic or a natural material such as rubber.
  • Wall 16 may be elastic or inelastic depending on the acceleration desired for wall 16 during its return stroke.
  • the impulse generator may be connected to a suitable fluid pressure and vacuum source means, not shown, for applying fluid pressure to and removing fluid pressure from chamber 14. Fluid pressure is applied to an inlet 24 coupled to a pressure line 26. The application of fluid pressure through inlet 24 into chamber 14 is controlled by a suitable valve 28 which may be pilot-operated by a fluid-pressure line 30. The fluid pressure fed to chamber 14 may be compressed air. It will be appreciated that the pressure source can be positioned on a vehicle or seismic boat and can be a compressor operated with diesel fuel to compress air which is freely available.
  • receivers 32, 34 and 36 are shown, respectively communicating with chamber 14 through outlets 38, 40 and 42.
  • receiver 36 communicates with chamber 14 through three outlets 42, chamber 34 through three outlets 40, and chamber 32 through three outlets 38.
  • Outlets 38, 40 and 42 are controlled through pilot-operated valves 46, 48 and 50.
  • a fluid pressure line 52 which may be controlled by a solenoid-operated valve (not shown), and connected to the fluid pressure source.
  • Line 52 branches out into substantially equal-length branches 54, 56 and 58.
  • the volume of receivers 32-36 is selected to provide for a very rapid evacuation of the fluid from chamber 14.
  • Receivers 32, 34 and 36 are maintained continuously at a vacuum by a vacuum-operated conduit 60 having three branch lines 62, 64 and 66 coupled to suitable inlets 68, 70 and 72, respectively.
  • the pumping means which applies fluid pressure to chamber 14 may also be used to evacuate chamber 14.
  • the fluid pressure and vacuum source forms no part of this invention.
  • Generator 10 is normally attached to be towed by a vehicle such as a seismic boat (not shown) as by a pair of cables 74.
  • Flexible wall 16 will execute it forward stroke by inflating chamber 14, by closing valves 46, 48 and 50 and by opening valve 28. Fluid pressure is then allowed to enter chamber 14 through inlet 24.
  • the inflation of chamber 14 may have a time period which is relatively long compared to the duration of the evacuation of chamber 14.
  • the movement of flexible wall 16 displaces a column of water in front of wall 16 thereby storing potential energy in the displaced water. This potential energy is proportional to the product of the ambient pressure and the volume of the water displaced.
  • wall 16 If wall 16 is inelastic it will not stretch appreciably and no potential energy will be stored in wall 16. On the other hand, if wall 16 is elastic it will stretch by the application of sufiicient fluid pressure through line 26. The stretching of elastic wall 16 allows it to store potential energy. When chamber 14 is inflated as shown in FIG. 2, wall 16 is in its cocked or fire position.
  • valve 28 is closed and valves 46, 48 and 50 are simultaneously opened thereby opening outlets 38, 40 and 42 respectively.
  • the fluid from chamber 14, which as previously mentioned may be compressed air, is rapidly evacuated into local vacuum receivers 32, 34 and 36,
  • a relatively large volume vacuum receiver positioned on the deck of the seismic boat, may be used in connection with the vacuum source.
  • the surrounding water remains in contact with wall 16 during it return stroke and produces an acoustic impulse when wall 16 abruptly comes to rest against the anvil wall 18.
  • the acceleration of wall 16 is primarily determined by the potential energy stored in the volume of displaced water.
  • the resilient wall 16 is secured to the top face of end wall 18 by a plurality of bolted clamps 80.
  • the anvil wall 82 has a curved cross-section, and wall 82 may be semi-elliptical or semi-spherical in shape.
  • a high-pressure fluid line 84 communicates with inlet 86 through a solenoidoperated valve 88. High-pressure line 84 will inflate chamber 14 in a manner previously described.
  • first means defining an enclosed chamber having an elastic wall at least about a portion of the periphery of said chamber
  • said driving means in one operating condition causing said elastic wall to execute a forward stroke in said liquid body thereby storing potential energy in said liquid body and in said elastic wall,
  • said driving means in another operating condition allowing said elastic wall to execute a return stroke in a short time interval thereby generating said acoustic impulse
  • said time interval is sufficiently short to allow for the formation of a cavity between said wall and said liquid body

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  • Engineering & Computer Science (AREA)
  • Remote Sensing (AREA)
  • Physics & Mathematics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Acoustics & Sound (AREA)
  • Environmental & Geological Engineering (AREA)
  • Geology (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Geophysics (AREA)
  • Physical Water Treatments (AREA)
  • Surgical Instruments (AREA)
  • Geophysics And Detection Of Objects (AREA)
  • Apparatuses For Generation Of Mechanical Vibrations (AREA)
US844152A 1969-07-23 1969-07-23 Extended area acoustic impulse generator Expired - Lifetime US3670839A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US84415269A 1969-07-23 1969-07-23

Publications (1)

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US3670839A true US3670839A (en) 1972-06-20

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US (1) US3670839A (de)
BR (1) BR7019899D0 (de)
CA (1) CA951011A (de)
DE (1) DE2024169B2 (de)
FR (1) FR2060561A5 (de)
GB (1) GB1302394A (de)
NO (1) NO127523B (de)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3949831A (en) * 1971-05-07 1976-04-13 Institut Francaise De Petrole, Des Carburants Et Lubrifiants Device for generating acoustic waves in a liquid medium
US4182428A (en) * 1978-04-17 1980-01-08 Western Geophysical Company Of America Hydraulically-coupled, land seismic signal source
US4739859A (en) * 1986-04-10 1988-04-26 Bolt Technology Corporation Method and apparatus for reducing the stretch of an elastomeric diaphragm of a land seismic source
US5375100A (en) * 1993-08-02 1994-12-20 Abbotsbury Software Limited Gas-operated apparatus for making a noise under water
WO2000046614A1 (en) * 1999-02-04 2000-08-10 Baker Hughes Incorporated High-power acoustic source for marine seismic operations
US20110070031A1 (en) * 2009-09-23 2011-03-24 Scott Raymond Frazier System for underwater compressed fluid energy storage and method of deploying same
US20110211916A1 (en) * 2010-03-01 2011-09-01 Scott Raymond Frazier Apparatus for storage vessel deployment and method of making same
US9557079B2 (en) 2010-07-14 2017-01-31 Bright Energy Storage Technologies, Llp System and method for storing thermal energy
US11194067B1 (en) 2018-06-28 2021-12-07 Falmouth Scientific Incorporated Highly adaptable seismic source

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3233694A (en) * 1962-08-10 1966-02-08 Shell Oil Co High energy acoustic impulse source
US3277437A (en) * 1965-04-05 1966-10-04 Gen Dynamics Corp Acoustic apparatus
US3369627A (en) * 1966-07-25 1968-02-20 Edward G. Schempf Mechanical imploder and method for generating under water seismic signals
US3480101A (en) * 1967-06-05 1969-11-25 Exxon Production Research Co Seismic wave source using explosive gas in an expansible enclosure
US3522862A (en) * 1968-05-20 1970-08-04 Clive R B Lister Method and means for generating acoustic pressure in fluid medium

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3233694A (en) * 1962-08-10 1966-02-08 Shell Oil Co High energy acoustic impulse source
US3277437A (en) * 1965-04-05 1966-10-04 Gen Dynamics Corp Acoustic apparatus
US3369627A (en) * 1966-07-25 1968-02-20 Edward G. Schempf Mechanical imploder and method for generating under water seismic signals
US3480101A (en) * 1967-06-05 1969-11-25 Exxon Production Research Co Seismic wave source using explosive gas in an expansible enclosure
US3522862A (en) * 1968-05-20 1970-08-04 Clive R B Lister Method and means for generating acoustic pressure in fluid medium

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3949831A (en) * 1971-05-07 1976-04-13 Institut Francaise De Petrole, Des Carburants Et Lubrifiants Device for generating acoustic waves in a liquid medium
US4182428A (en) * 1978-04-17 1980-01-08 Western Geophysical Company Of America Hydraulically-coupled, land seismic signal source
US4739859A (en) * 1986-04-10 1988-04-26 Bolt Technology Corporation Method and apparatus for reducing the stretch of an elastomeric diaphragm of a land seismic source
US5375100A (en) * 1993-08-02 1994-12-20 Abbotsbury Software Limited Gas-operated apparatus for making a noise under water
GB2361829A (en) * 1999-02-04 2001-10-31 Baker Hughes Inc High-power acoustic source for marine seismic operations
FR2789494A1 (fr) * 1999-02-04 2000-08-11 Baker Hughes Inc Source d'energie acoustique et procede pour generer une impulsion de pression dans l'eau, et source sismique marine
WO2000046614A1 (en) * 1999-02-04 2000-08-10 Baker Hughes Incorporated High-power acoustic source for marine seismic operations
GB2361829B (en) * 1999-02-04 2003-10-01 Baker Hughes Inc High-power acoustic source for marine seismic operations
US20110070031A1 (en) * 2009-09-23 2011-03-24 Scott Raymond Frazier System for underwater compressed fluid energy storage and method of deploying same
US20110070032A1 (en) * 2009-09-23 2011-03-24 Scott Raymond Frazier Underwater compressed fluid energy storage system
US9022692B2 (en) 2009-09-23 2015-05-05 Bright Energy Storage Technologies, Llp System for underwater compressed fluid energy storage and method of deploying same
US9139974B2 (en) 2009-09-23 2015-09-22 Bright Energy Storage Technologies, Llp Underwater compressed fluid energy storage system
US20110211916A1 (en) * 2010-03-01 2011-09-01 Scott Raymond Frazier Apparatus for storage vessel deployment and method of making same
US9557079B2 (en) 2010-07-14 2017-01-31 Bright Energy Storage Technologies, Llp System and method for storing thermal energy
US11194067B1 (en) 2018-06-28 2021-12-07 Falmouth Scientific Incorporated Highly adaptable seismic source

Also Published As

Publication number Publication date
DE2024169B2 (de) 1971-07-22
CA951011A (en) 1974-07-09
DE2024169A1 (de) 1971-02-11
NO127523B (de) 1973-07-02
FR2060561A5 (de) 1971-06-18
BR7019899D0 (pt) 1973-04-05
GB1302394A (de) 1973-01-10

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Owner name: WESTERN ATLAS INTERNATIONAL, INC., 10,001 RICHMOND

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:WESTERN GEOPHYSICAL COMPANY OF AMERICA, A CORP OF DE;REEL/FRAME:004725/0239

Effective date: 19870430