WO2011103336A1 - Transducteurs et semelles sismiques dotés d'amortisseurs externes et procédés pour leur utilisation - Google Patents

Transducteurs et semelles sismiques dotés d'amortisseurs externes et procédés pour leur utilisation Download PDF

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Publication number
WO2011103336A1
WO2011103336A1 PCT/US2011/025307 US2011025307W WO2011103336A1 WO 2011103336 A1 WO2011103336 A1 WO 2011103336A1 US 2011025307 W US2011025307 W US 2011025307W WO 2011103336 A1 WO2011103336 A1 WO 2011103336A1
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WO
WIPO (PCT)
Prior art keywords
baseplate
seismic
reaction mass
frame
dampener
Prior art date
Application number
PCT/US2011/025307
Other languages
English (en)
Inventor
Peter M. Eick
Joel D. Brewer
Shan SHAN
Original Assignee
Conocophillips Company
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US13/028,007 external-priority patent/US8342288B2/en
Application filed by Conocophillips Company filed Critical Conocophillips Company
Priority to CA2787087A priority Critical patent/CA2787087C/fr
Priority to AU2011218034A priority patent/AU2011218034B2/en
Publication of WO2011103336A1 publication Critical patent/WO2011103336A1/fr

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Classifications

    • 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
    • G01V1/143—Generating seismic energy using mechanical driving means, e.g. motor driven shaft
    • G01V1/155—Generating seismic energy using mechanical driving means, e.g. motor driven shaft using reciprocating masses

Definitions

  • the present invention relates generally to methods and systems for inducing seismic vibrations into an elastic medium. More particularly, but not by way of limitation, embodiments of the present invention include methods and systems for inducing seismic vibrations into subterranean formations utilizing baseplates having external dampeners.
  • the reflected seismic waves are detected at the surface by a group of spaced apart receivers called geophones, accelerometers, seismometers or similar transducers. These transducers are collectively referred to as "geophones" herein following industry convention, but it is understood that they could be any sensor that converts seismic energy into some readable data.
  • the reflected seismic waves detected by the geophones are analyzed and processed to generate seismic data representative of the nature and composition of the subterranean formation at various depths, including the nature and extent of hydrocarbon deposits. In this way, the seismic information collected by geophones can be used to produce seismic reflection signals which can be processed to form images of the subsurface.
  • a vibrator It has become common in many cases to use, as the source of propagating elastic waves, a hydraulically-operated vibratory source more simply referred to as a vibrator.
  • energy sources for vibrators like electromechanical or pure electric. All of these systems typically generate vibrations or shock waves by using a reaction mass member that is actuated by a hydraulic or electric system and electrically controlled by a servo valve.
  • a vibrator comprises a double ended piston rigidly affixed to a coaxial piston rod. The piston is located in reciprocating relationship in a cylinder formed within a heavy reaction mass.
  • Means are included for alternately introducing hydraulic fluid under high pressure to opposite ends of the cylinder or for an electric coil and magnet type assembly to impart a reciprocating motion to the piston relative to the reaction mass.
  • the piston rod extending from the reaction mass is rigidly coupled to a baseplate, which is maintained in intimate contact with ground surface. Since the inertia of the reaction mass tends to resist displacement of the reaction mass relative to the earth, the motion of the piston is coupled through the piston rod and baseplate to impart vibratory seismic energy in the earth.
  • vibrators are transported by carrier vehicle, and it is also known to prevent decoupling of the baseplate from the ground by applying a portion of the carrier vehicle's weight to the baseplate during operation.
  • the weight of the carrier vehicle is frequently applied to the baseplate through one or more spring and stilt members, each having a large compliance, with the result that a static bias force is imposed on the baseplate, while the dynamic forces of the baseplate are decoupled from the carrier vehicle itself.
  • the hydraulic system forces the reaction mass to reciprocate vertically, at the desired vibration frequency, through a short vertical stroke.
  • This type of vibrational seismic exploration system typically uses a quasi-sinusoidal reference signal, or so-called pilot signal, of continuously varying frequency, selected band width, and selected duration to control the introduction of seismic waves into the earth.
  • the pilot signal is converted into a mechanical vibration in a land vibrator having a baseplate which is coupled to the earth.
  • the land vibrator is typically mounted on a carrier vehicle, which provides locomotion.
  • the baseplate is contacted with the earth's surface and the weight of the carrier vehicle is applied to the baseplate.
  • a servo-hydraulic piston connected to the baseplate is then excited by the pilot signal, causing vibration of the baseplate against the earth.
  • a significant problem with conventional systems employing a vibrating baseplate to impart seismic waves into the earth is that the actual motion of the baseplate, and thus the actual seismic energy imparted to the earth, is different from the ideal motion represented by the pilot signal.
  • This difference can be caused by a variety of factors, including (1) harmonic distortion or "ringing" of the baseplate, (2) decoupling of the baseplate from the earth's surface commonly referred to as bouncing or "pogo-sticking," and (3) flexure of the baseplate.
  • the differences between the pilot signal and the actual baseplate motion are problematic because, in the past, the pilot signal was used to pulse-compress the reflected seismic signal either through correlation or inversion.
  • the pulse-compressed reflected seismic signal that is produced by correlation or more modernly by inversion is inaccurate.
  • the present invention relates generally to methods and systems for inducing seismic vibrations into an elastic medium. More particularly, but not by way of limitation, embodiments of the present invention include methods and systems for inducing seismic vibrations into subterranean formations utilizing baseplates having external dampeners.
  • One example of a method for inducing seismic energy waves in a subterranean formation comprises the steps of: providing a seismic transducer apparatus comprising a frame, a baseplate attached to the frame, the baseplate having a lower surface, an external dampener secured to the lower surface of the baseplate, a reaction mass supported by the frame, and a driver configured to actuate the reaction mass in a reciprocating motion so as to impart vibratory energy to the baseplate; engaging the ground surface with the external dampener; actuating the reaction mass via the driver in a reciprocating motion; allowing vibratory energy to be imparted to the baseplate so as to propagate seismic energy waves through the external dampener in the subterranean formation; allowing the seismic energy waves to propagate through the subterranean formation so as to produce reflected and refracted seismic energy waves; and detecting one or more of the reflected and refracted seismic energy waves.
  • One example of a seismic transducer apparatus for inducing energy waves in an elastic medium comprises: a frame; a baseplate attached to the frame, the baseplate having a lower surface; an external dampener secured to the lower surface of the baseplate; a reaction mass supported by the frame; and a driver configured to actuate the reaction mass in a reciprocating motion so as to impart vibratory energy to the baseplate.
  • the external dampener may be affixed to an upper surface of the baseplate. In still other embodiments, the external dampener may be affixed to both the lower and upper surface of the baseplate.
  • Figure 1 illustrates a side view of one example of a seismic exploration system in accordance with one embodiment of the present invention.
  • Figure 2A illustrates a side view of one example of a seismic transducer having an external dampener affixed to the lower surface of a baseplate in accordance with one embodiment of the present invention.
  • Figure 2B illustrates a side view of one example of a seismic transducer having an external dampener affixed to the upper surface of a baseplate in accordance with one embodiment of the present invention.
  • the present invention relates generally to methods and systems for inducing seismic vibrations into an elastic medium. More particularly, but not by way of limitation, embodiments of the present invention include methods and systems for inducing seismic vibrations into subterranean formations utilizing baseplates having external dampeners.
  • seismic transducers in accordance with the present invention comprise a frame, a reaction mass supported by the frame, a driver, and a baseplate attached to the frame.
  • the driver actuates the reaction mass in a reciprocating motion, imparting a vibratory energy to the baseplate.
  • the baseplate is engaged with a ground surface during operation, the vibratory energy of the baseplate is imparted directly to the ground surface so as to propagate seismic waves into the subterranean formation.
  • the seismic waves are then reflected and refracted by the subsurface strata and geological features.
  • the reflected and refracted seismic waves may then be detected by a plurality of seismic detectors.
  • the detected seismic data is then interpreted to reveal seismic information representative of the surveyed region of the earth.
  • a dampener may be secured to the lower surface of the baseplate.
  • the dampener may be an elastomeric dampener.
  • dampeners in accordance with the present invention provide a damping effect to the induced seismic waves of the baseplate. Advantages of adding such dampeners include, but are not limited to, a reduction of undesirable baseplate harmonics and ringing, reduced baseplate decoupling, and reduction of seismic noise due to a reduction of flexure and more uniform source point to source point coupling.
  • FIG. 1 illustrates a side view of one example of a seismic exploration system in accordance with one embodiment of the present invention.
  • a pilot signal is generated in recorder/processor carrier vehicle 111 and sent by radio wave link 112 to a land vibrator 120.
  • Land vibrator 120 converts the pilot signal into mechanical motion that vibrates baseplate 130.
  • Dampener 138 is secured or otherwise affixed to the lower surface of baseplate 130. Dampener 138 contacts ground surface 180 of the earth and is coupled to ground surface 180 by the weight of carrier vehicle 110.
  • Baseplate 130 imparts induced seismic waves 162 through dampener 138 into subsurface 182 of the earth.
  • dampener 138 extends across baseplate 130 so as to cover the substantial entirety of the lower surface of baseplate 130.
  • Induced seismic wave 162 travels downward through subsurface 182 and is altered (i.e., refracted and/or reflected) by subsurface strata 183.
  • Altered seismic waves 164 travels from subsurface strata 183 upward through subsurface 182 to surface 180.
  • Seismic receivers 185 such as geophones, located on surface 180, are generally spaced apart from each other and from land vibrator 120. Seismic receivers 185 measure altered seismic waves 164 at surface 180 and transmit an altered seismic signal indicating altered seismic wave 28 across geophone lines 184 to recorder/processor carrier vehicle 110. This communication may be accomplished via wires conventionally, or with autonomous recorders where the data is later collected and transcribed to the recording media.
  • a baseplate signal is transmitted from land vibrator 120 via radio wave link 112 to recorder/processor carrier vehicle 110 for processing. In this way, seismic survey data is collected and interpreted so as to reveal the nature and the geology of subterranean formation 182.
  • FIG. 2A illustrates a side view of one example of a seismic transducer having an external dampener affixed to the lower surface of a baseplate in accordance with one embodiment of the present invention.
  • Seismic transducer apparatus 200 utilizes a reciprocating motion of reaction mass 225 to impart vibratory energy to baseplate 230.
  • frame 222 supports and is rigidly connected to piston rod 223 and baseplate 230.
  • Driver 224 pumps or otherwise supplies hydraulic fluid to hydraulic cylinder 227 through ports 225. In this way, driver 224 actuates reaction mass 226 about piston rod 223.
  • reaction mass 226 is supported by frame 222, this reciprocating motion is transmitted to baseplate 230 via the inertia of reaction mass 226.
  • baseplate 230 transmits the vibratory energy through dampener 238 to a ground surface (such as ground surface 180 depicted in Figure 1).
  • Dampener 238 may comprise any material known in the art suitable for producing a damping effect on baseplate 230.
  • suitable damping materials include, but are not limited to, rubber, carbon-fiber impregnated rubber, viscoelastic damping polymers, elastomeric composites, synthetic and natural elastomeric materials, or any combination thereof.
  • external dampener 238 Another advantage provided by external dampener 238 is its ability to provide for enhanced source point to source point coupling. That is, under certain conditions such as a rough or non-uniform ground surface, a rigid, flat baseplate is unable to couple directly to the ground along the entire surface area of the baseplate. The non-uniformity of the ground can thus result in areas of the baseplate that are not directly coupled to the ground, leaving substantial gaps between the portions of the baseplate and the non-uniform ground.
  • External dampener 238, in certain embodiments, such as when made of an elastomeric material, can conform to the ground surface along areas of minimal non-uniformity. That is, external dampener 238 may be capable of "filling- in the gaps" due to the somewhat elastic nature of external dampener 238. In this way, external dampener 238 provides superior source point to source point coupling.
  • dampener 238 is secured to only a portion of the lower surface of baseplate 230.
  • dampener 238 may be secured or otherwise affixed to about 30% to about 75% of the surface area of the lower surface of baseplate 230.
  • dampener 238 may be comprised of a plurality of individual dampener elements, separately affixed to baseplate 230. Among other advantages, providing a plurality of individual dampener elements allows for ease of replacement if individual elements are damaged or if a different damping material is determined to function better in a particular geological circumstance.
  • dampener 238 may be tuned to provide optimal reduction of seismic noise and undesirable harmonics.
  • dampener 238 may vary from about 1 ⁇ 2 inches to about 4 inches.
  • Terrain and geological conditions will influence optimal baseplate dimensions and configuration. Accordingly, different thicknesses and materials may be required in different areas.
  • dampener 238 comprises an elastomer having a density of at least about 80 lbs/ft 3 , a density of at least about 90 to about 150 lbs/ft 3 , or a density of at least about 100 to about 200 lbs/ft 3 .
  • Dampeners 238 may comprise elastomers having compressive strengths of at least about 15 psi and in other embodiments, of at most about 15,000 psi. In other embodiments, dampeners 238 may comprise elastomers having compressive strengths of at least about 150 psi and in other embodiments, of at most about 150 psi.
  • seismic transducers of the present invention operate at frequency ranges extending into the higher seismic frequency range of at least about 50 cycles per second, at least about 150 cycles per second, and/or at least about 250 cycles per second.
  • FIG. 2B illustrates a side view of one example of a seismic transducer having an external dampener affixed to the upper surface of a baseplate in accordance with one embodiment of the present invention.
  • external dampener 238 is affixed to the upper surface of baseplate 230.
  • external dampener 238 still performs its function of reducing or eliminating harmonics or ringing from baseplate 230. In this configuration, however, external dampener 238 is not exposed directly to impact with a ground surface and thus may avoid premature damage or deterioration.
  • some embodiments may comprise external dampeners 238 affixed to both the lower and upper surfaces of baseplate 230 to provide enhanced damping of baseplate 230.
  • External dampener 238 may be secured to the surface of baseplate 230 by any manner known in the art for affixing a dampener pad to a baseplate, including but not limited to, using adhesive, welding, screws, bolts, or any combination thereof.
  • baseplate 230 may comprise reinforcing ribs 234. These ribs or I-beams provide additional reinforcement while allowing for a much lighter baseplate. Thus, such a baseplate may be more resistant to flexure and fatigue failures while at the same time avoiding the severe weight penalty that a corresponding solid baseplate would impose. In this way, baseplate plate 230 may be maintained within acceptable weight limitations and yet be capable of withstanding large forces generated by a seismic transducer

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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)
  • Geophysics And Detection Of Objects (AREA)

Abstract

L'invention concerne des procédés et des systèmes destinés à induire des vibrations sismiques dans des formations souterraines. Les transducteurs sismiques peuvent comporter un bâti, une masse de réaction, un excitateur et une semelle. L'excitateur actionne la masse de réaction, communiquant une énergie vibratoire à la semelle. Cette énergie vibratoire est alors directement communiquée à la surface du sol afin de propager des ondes sismiques dans la formation. Ces ondes sismiques sont alors réfléchies par des entités géologiques du sous-sol. Les ondes sismiques réfléchies peuvent alors être détectées et interprétées par des détecteurs sismiques afin de révéler des informations sismiques représentatives de la région explorée. Un amortisseur externe peut être fixé à la semelle, ce qui exerce, entre autres, un effet d'amortissement bénéfique sur la semelle. Entre autres avantages, on peut citer une réduction de la distorsion harmonique indésirable des semelles ou "tintement", un découplage réduit des semelles et un bruit sismique réduit en raison d'une réduction de la flexion et d'une adaptation semelle-sol plus uniforme. Ces avantages se traduisent par des relevés sismiques améliorés, caractérisés par une plus haute résolution des formations et atteignant des profondeurs plus importantes.
PCT/US2011/025307 2010-02-18 2011-02-17 Transducteurs et semelles sismiques dotés d'amortisseurs externes et procédés pour leur utilisation WO2011103336A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
CA2787087A CA2787087C (fr) 2010-02-18 2011-02-17 Transducteurs et semelles sismiques dotes d'amortisseurs externes et procedes pour leur utilisation
AU2011218034A AU2011218034B2 (en) 2010-02-18 2011-02-17 Seismic transducers and baseplates having external dampeners and methods of use

Applications Claiming Priority (12)

Application Number Priority Date Filing Date Title
US30569710P 2010-02-18 2010-02-18
US30568910P 2010-02-18 2010-02-18
US30569210P 2010-02-18 2010-02-18
US61/305,689 2010-02-18
US61/305,692 2010-02-18
US61/305,697 2010-02-18
US13/027,982 2011-02-15
US13/028,007 US8342288B2 (en) 2010-02-18 2011-02-15 Seismic transducers having reduced surface area baseplates and methods of use
US13/028,029 2011-02-15
US13/028,007 2011-02-15
US13/027,982 US8167082B2 (en) 2010-02-18 2011-02-15 Seismic transducers having improved polygonal baseplates and methods of use
US13/028,029 US8261875B2 (en) 2010-02-18 2011-02-15 Seismic transducers and baseplates having external dampeners and methods of use

Publications (1)

Publication Number Publication Date
WO2011103336A1 true WO2011103336A1 (fr) 2011-08-25

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PCT/US2011/025307 WO2011103336A1 (fr) 2010-02-18 2011-02-17 Transducteurs et semelles sismiques dotés d'amortisseurs externes et procédés pour leur utilisation
PCT/US2011/025304 WO2011103333A1 (fr) 2010-02-18 2011-02-17 Transducteurs sismiques dotés de semelles d'aire surfacique réduite et procédés pour leur utilisation
PCT/US2011/025302 WO2011103331A1 (fr) 2010-02-18 2011-02-17 Transducteurs sismiques dotés de semelles polygonales améliorées et procédés pour leur utilisation

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PCT/US2011/025304 WO2011103333A1 (fr) 2010-02-18 2011-02-17 Transducteurs sismiques dotés de semelles d'aire surfacique réduite et procédés pour leur utilisation
PCT/US2011/025302 WO2011103331A1 (fr) 2010-02-18 2011-02-17 Transducteurs sismiques dotés de semelles polygonales améliorées et procédés pour leur utilisation

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US4026383A (en) * 1974-11-04 1977-05-31 Texas Instruments Incorporated Gyroscopic vibrator
US4406345A (en) * 1979-08-08 1983-09-27 Conoco Inc. Seismic transducer baseplate and housing assembly
US5292811A (en) * 1988-11-21 1994-03-08 Mitsui Petrochemical Industries, Ltd. Process for preparing thermoplastic elastomers
US20020149998A1 (en) * 2001-03-07 2002-10-17 Phillips Petroleum Company Method and apparatus for measuring seismic energy imparted to the earth
US20040032795A1 (en) * 2000-12-21 2004-02-19 Axelle Baroni Device for generating focused elastic waves in a material medium such as underground, and method using same

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GB8414907D0 (en) * 1984-06-12 1984-07-18 Shell Int Research Multisensor ground-force measuring means
US4676337A (en) * 1985-09-03 1987-06-30 Western Geophysical Company Of America Seismic vibrator baseplate
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Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2684352A (en) * 1953-10-12 1954-07-20 Us Rubber Co High impact strength thermoplastic composition containing polyvinyl acetal resin and butadiene elastomer
US4026383A (en) * 1974-11-04 1977-05-31 Texas Instruments Incorporated Gyroscopic vibrator
US4406345A (en) * 1979-08-08 1983-09-27 Conoco Inc. Seismic transducer baseplate and housing assembly
US5292811A (en) * 1988-11-21 1994-03-08 Mitsui Petrochemical Industries, Ltd. Process for preparing thermoplastic elastomers
US20040032795A1 (en) * 2000-12-21 2004-02-19 Axelle Baroni Device for generating focused elastic waves in a material medium such as underground, and method using same
US20020149998A1 (en) * 2001-03-07 2002-10-17 Phillips Petroleum Company Method and apparatus for measuring seismic energy imparted to the earth

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Publication number Publication date
WO2011103333A1 (fr) 2011-08-25
WO2011103331A1 (fr) 2011-08-25

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