US20130228017A1 - Systems and methods for cluster validation - Google Patents

Abstract

A seismic vibrator has a baseplate composed at least partially of a composite material. The baseplate has a body composed of the composite material and has top and bottom plates composed of a metallic material. The top plate supports isolators for isolating the vibrator's mass and frame from the baseplate. Internally, the composite body has a central structure to which couple stilts for supporting the mass and a piston for the vibrator's actuator. A lattice structure surrounds the central structure. This lattice structure has radial ribs extending from the central structure and has radial ribs interconnecting the radial ribs.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS
• This is a non-provisional of U.S. Appl. No. 61/393,129, filed 14 Oct. 2010, which is incorporated herein by reference and to which priority is claimed.
BACKGROUND OF THE DISCLOSURE
• In a geophysical survey, a seismic source can be carried by a truck and positioned at a predetermined location in an area of exploration. The seismic source can be a single axis vibratory source and can impart compressing P-waves into the earth once coupled to the earth and operated. Avibrator10 according to the prior art is illustrated inFIG. 1A and is diagrammatically illustrated inFIG. 1B. Thevibrator10 transmits force into the ground using abaseplate20 and a reaction mass50.
• As is typical, thevibrator10 is mounted on a carrier vehicle (not shown) that uses a mechanism andbars12/14 to lower thevibrator10 to the ground. With thevibrator10 lowered, the weight of the vehicle holds thebaseplate20 engaged with the ground so seismic source signals can be transmitted into the earth. The reaction mass50 positions directly abovebaseplate20 and stilts52 extend from thebaseplate20 and through the mass50 to stabilize it.
• Internally, the reaction mass50 has a cylinder56 formed therein. A vertically extendingpiston60 extends through this cylinder56, and a head62 on thepiston60 divides the cylinder56 into upper and lower chambers. Thepiston60 connects at its lower end to a hub in a lower cross-piece54L and extends upward through the cylinder56. Thepiston60's upper end connects to a hub on an upper cross-piece54U, and the cross pieces54U-L connect to the stilts52.
• To isolate thebaseplate20 from the bars14, the bars14 have feet16 withisolators40 disposed between the feet16 and thebaseplate20. In addition, the feet16 havetension members42 interconnected between the edges of the feet16 and thebaseplate20. Thetension members42 are used to hold thebaseplate20 when thevibrator10 is raised and lowered to the ground. Finally, shock absorbers44 are also mounted between the bottom of the feet16 and thebaseplate20 to isolate vibrations therebetween.
• During operation, a controller80 as shown inFIG. 1B receives signals from a first sensor85 coupled to the upper cross-piece54U and receives signals from a second sensor87 coupled to the reaction mass50. Based on feedback from these sensors85/87 and a desired sweep signal for operating thevibrator10, the controller80 generates a drive signal to control a servo valve assembly82. Driven by the drive signal, the servo valve assembly82 alternatingly routes high pressure hydraulic fluid between ahydraulic fluid supply84 and upper and lower cylinder piston chambers via ports in the mass50. As hydraulic fluid alternatingly accumulates in the piston's chambers located immediately above and below the piston head62, the reaction mass50 reciprocally vibrates in a vertical direction on thepiston60. In turn, the force generated by the vibrating mass50 transfers to thebaseplate20 via the stilts52 and thepiston60 so that thebaseplate20 vibrates at a desired amplitude and frequency or sweep to generate a seismic source signal into the ground.
• As the moving reaction mass50 acts upon thebaseplate20 to impart a seismic source signal into the earth, the signal travels through the earth, reflects at discontinuities and formations, and then travels toward the earth's surface. At the surface, an array of geophone receivers (not shown) coupled to the earth detects the reflected signal, and a recording device records the signals from the geophone receivers. The seismic recorder can use a correlation processor to correlate the computed ground force supplied by the seismic source to the seismic signals received by the geophone receivers.
• As can be seen, an essential component of thevibrator10 is itsbaseplate20.FIGS. 2A-2C show thebaseplate20 for theprior art vibrator10 in plan, side, and end-sectional views. The top of theplate20 has stiltmounts24 for the stilts (52;FIG. 1B), and areinforcement pad21 surrounds thesemounts24. Retaining ledges26 are provided for the isolators (40). The long edges near the corners have forkedhangers28 to which ends of the tension members (42) connect, andreinforcement pads27 are provided around the outside edges of theplate20 for connecting the shock absorbers (44) to thebaseplate20.
• Overall, thebaseplate20 can have a height H₁of about 6.9-in., a width W₁of about 42-in., and a length L₁of about 96-in., and theplate20 can weight approximately 4020-lbs. As shown in the end section ofFIG. 2C, theplate20 has four internal tubes orbeams30 that run longitudinally along the plate's length. Thebeams30 are hollow tubes with rectangular cross-sections and have a height of about 6-in., a width of about 4-in., and a wall thickness of about ⅜-in. Interconnecting spacers32 position between thebeams30 and between the long cap walls of thebaseplate20.
• When operating such aprior art vibrator10, operators experience problems in accurately imparting desired force into the ground with thevibrator10 and thebaseplate20. Ideally, operators would like thevibrator10 to efficiently impart force into the ground with thebaseplate20. Also, operators would like to know the actual ground force applied by thebaseplate20 to the ground when imparting the seismic energy. Unfortunately, thebaseplate20 experiences a great deal of vibration and flexure that can distort or interfere with the ideal operation of thebaseplate20.
• Although the typical prior art vibrator and baseplate may be effective, operators are continually seeking more efficient ways to impart seismic energy into the ground for a seismic survey.
SUMMARY OF THE DISCLOSURE
• A seismic vibrator has a baseplate, a mass, an actuator, and a controller. The mass is movably disposed relative to the baseplate for imparting vibrational energy thereto, and the actuator is coupled to the mass for moving the mass relative to the baseplate. The controller is communicatively coupled to the actuator and controls operation of the actuator.
• Rather than having a conventional construction, the baseplate has a core body composed of a composite material and has top and bottom plates composed of a metallic material. The top plate supports isolators for isolating the vibrator's mass and frame from the baseplate. Internally, the composite core body has a central structure to which couple stilts for supporting the mass and to which couples a piston for the vibrator's actuator. A lattice structure surrounds the central structure. This lattice structure has main or radial ribs extending from the central structure and has circumferential or interconnecting ribs interconnecting the radial ribs.
• Journals are disposed in the body from a central mount at the top surface to the bottom surface. The stilts for supporting the mass couple to these journals. A central journal is also disposed in the body, and the piston for the actuator disposed through the mass couples to the central journal.
• The baseplate can have a top component and a bottom component that connect together to form the core body. The top component has a top surface and an outer wall extending therefrom, while the bottom component has a bottom surface and an inner wall extending therefrom. The top component positions on the bottom component with the outer sidewall fitting around the inner wall.
• Finally, the bottom surface of the baseplate can have a round perimeter, while the top surface can have a rectangular perimeter with shelves extending beyond the round perimeter of the bottom surface. The baseplate, however, can have any desirable shape, including, for example, round, square, rectangular, polygonal.
• The foregoing summary is not intended to summarize each potential embodiment or every aspect of the present disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1A shows a vibrator according to the prior art in a perspective view.
• FIG. 1B schematically illustrates the prior art vibrator ofFIG. 1A.
• FIGS. 2A-2C illustrate the baseplate for the prior art vibrator in plan, side, and end-section views.
• FIGS. 3A-3D show a vibrator according to the present disclosure in perspective, front, side, and cross-sectional views.
• FIGS. 4A-4D show the baseplate of the disclosed vibrator in perspective, perspective cross-sectional, longitudinal cross-sectional, and lateral cross-sectional views.
• FIGS. 5A-5B show the composite body of the disclosed baseplate in a perspective top view and in a bottom view.
• FIGS. 6A-6B show the composite body of the disclosed baseplate in a top cross-sectional view and in a bottom cross-sectional view.
• FIGS. 7A-7B show the bottom assembly of the disclosed baseplate in top and bottom perspective views.
• FIG. 8 shows the top plate of the disclosed baseplate in an upper perspective view.
• FIG. 9 shows the bottom plate of the disclosed baseplate in an upper perspective view.
• FIG. 10A shows a cross-section of a piston journal for the disclosed baseplate.
• FIG. 10B shows a cross-section of a stilt journal for the disclosed baseplate.
• FIGS. 11A-11B show perspective views of another baseplate with a composite body according to the present disclosure.
• FIGS. 12A-12B show an exploded view and an exposed view of another partially composite baseplate according to the present disclosure.
• FIG. 12C shows an exploded view of the core body of the composite baseplate.
• FIGS. 12D-12E show longitudinal and lateral sectional views of the composite baseplate.
DETAILED DESCRIPTION OF THE DISCLOSURE
• A. Seismic Vibrator
• FIGS. 3A-3D show perspective, front, side, and cross-sectional views of aseismic vibrator100 according to certain teachings of the present disclosure. Thevibrator100 has a frame110, amoveable reaction mass150, and abaseplate200. The frame110 andmass150 can be constructed mainly of metal, such as steel or the like. By contrast, thebaseplate200 is at least partially composed of a composite material as described in more detail later.
• In general, thevibrator100 transmits force to the ground using thebaseplate200 and thereaction mass150, and thevibrator100 can operate similar to the vibrator detailed previously with reference toFIGS. 1A-1B. As is typical, for example, thevibrator100 is mounted on a carrier or vehicle (not shown) that uses the frame110 to lower thevibrator100 to the ground. With thevibrator100 lowered, the weight of the vehicle holds thebaseplate200 engaged with the ground so seismic source signals can be transmitted into the earth during operation. Other details of how thevibrator100 couples to the ground with a vehicle or other carrier are well known in the art and not detailed herein.
• When thevibrator100 is operated, the movingreaction mass150 acts upon thebaseplate200 to impart a seismic source signal into the ground. The seismic signal travels through the ground, reflects at discontinuities and formations, and travels toward the surface. Sensors coupled to the ground are arranged in an array spaced apart from thevibrator100. These sensors detect the reflected source signal, and a recording station typically housed in a truck record the signals from the sensors. The recording station includes a seismic recorder and can also include a correlation processor. Such a correlation processor receives a signal from thevibrator100 indicative of the source signal imparted into the earth and correlates the received signal with the recorded signals.
• As shown, thereaction mass150 positions directly above thebaseplate200. Asupport160 extends from thebaseplate200 through themass150 and stabilizes thereaction mass150. Thesupport160 is typically constructed usingstilts162, which can be tubular pipes or rods made of steel or the like. Thesestilts162 have ends affixed to thebaseplate200 and extend upward from thebaseplate200 and through thereaction mass150. Anupper cross-piece164, which may be constructed from steel, couples to the top ends of thestilts162 and provides stability to thesupport160 as themass150 vibrates.Isolators146 are provided on thebaseplate200 below thereaction mass150 for isolating vibrations.
• As noted above, the carrier vehicle applies its static weight to thebaseplate200 via the frame110 to hold thebaseplate200 against the ground. Yet, the contribution of the frame110 and vehicle to the resulting seismic force applied to the ground is preferably kept to a minimum. Therefore,several isolators140 are used between the frame110 and thebaseplate200 to isolate motion of thebaseplate200 from the frame110 and the vehicle.
• As shown inFIGS. 3A-3D, the frame110 has vertical support bars114 and ahorizontal bar112 connected to the tops of thesevertical bars114. At their distal ends, thevertical bars114 connect tofeet116. In turn, thesefeet116 connect to thebaseplate200 using an arrangement ofisolators140,pivotable pistons144, andtension members142. The arrangement of these components (140,142,144) essentially isolates the frame110 from thebaseplate200 and themovable mass150 supported thereon. In addition, the arrangement allows the vibratory force of themass150 to be applied to the ground via thebaseplate200 while minimizing the amount of force permitted to transmit back through the frame110 to the supporting vehicle.
• Eachvertical bar114 couples to one of thefeet116. Thepistons144 pivotably connect between thesefeet116 and thebaseplate200 and act as shock absorbers. Thetension members144 connect the outer edges of thefeet116 to the outer edge of thebaseplate200 and support theplate200 to thefeet116 when thevibrator100 is lifted off the ground.
• For their part, theisolators140 can be air bags or other isolating elements known and used in the art. Theisolators140 are situated somewhat outside of the main footprint of thebaseplate200. In particular, the outside corners of thefeet116 extend beyond the baseplate's footprint. Similarly,shelves218 on thebaseplate200 extend from its edges to support theisolators140 disposed between theseshelves218 and the extended corners of thefeet116.
• As best shown inFIG. 3D, thereaction mass150 has a cylinder176 internally therein that fits onto a vertically extendingpiston170. Thepiston170 connects at its lower end to apiston journal236 in thebaseplate200 and extends upward through the cylinder176. The piston's upper end connects to theupper cross piece164. Ahead172 on thepiston170 divides the cylinder176 into upper and lower chambers. Thispiston170 andreaction mass150 can be hydraulically actuated according to techniques known in the art so that they are not detailed herein.
• B. Baseplate
• With an understanding of thevibrator100, discussion now turns to further details of thebaseplate200.FIGS. 4A-4D show thebaseplate200 of the disclosedvibrator100 in perspective, perspective cross-section, longitudinal cross-section, and lateral cross-section. Thebaseplate200 has atop plate210, abottom assembly220, and an internalcomposite core body250. Most of thebaseplate200 is composed of metal, such as steel or the like, including thetop plate210 and thebottom assembly220. However, the internalcomposite core body250 is composed of a composite material, preferably having carbon fiber, although any suitable type of composite can be used. In general, the composite can be non-metallic and can have a matrix material (e.g., resin, polymer, etc.) and a reinforcement material (e.g., fiber strand, fiber mesh, or ground material) that meet the needs of the particular implementation. The choice of these materials and their ratio can be selected for strength and other factors.
• Thetop plate210 fits on top of thecomposite core body250 and acts as a surface for the various couplings of thebaseplate200 to other components of the vibrator (100). Thebottom assembly220 also fits around thecomposite core body250 and acts as the interface of thebaseplate200 with the ground during operation. Thebottom assembly220 has acentral mount230, abottom plate240, and skin elements222.
• Thetop plate210, which is shown in an isolated perspective view inFIG. 8, is preferably composed of steel and defines acentral opening212 and various features on its surface. Corners of thetop plate210 extend out from the sides of thebaseplate200 and have retainingledges214 for the isolators (140). Thetop plate210 has reinforcement pads217 for connecting the pistons (144) near the outside edges theplate210. In addition, the shorter edges of thetop plate210 can have forked hangers (not shown) to which ends of the tension members (142) connect. Other retainingledges216 are provided for the isolators (146) that fit below the reaction mass (150).
• As shown in each ofFIGS. 4A-4D, the baseplate'scentral mount230 is exposed in thecentral opening212 of thetop plate210. Thecentral mount230 has acentral piston journal236 for connection to the end of the vibrator's piston (170). (FIG. 10A shows a detailed cross-section of thepiston journal236.) Thepiston journal236 fits in a central opening of themount230, and the end of the piston (170) affixes in thepiston journal236 with fasteners. In this way, force applied to the piston (170) couples to themount230 and thecomposite core body250 of thebaseplate200 during operation of the vibrator (100).
• As best shown inFIG. 4A, around thispiston journal236, thecentral mount230 hasstilt journals234 for connection to the ends of the vibrator's stilts (162). As best shown inFIG. 7A, thestilt journals234 extend to thebottom plate240 of thebottom assembly220. (FIG. 10B shows a detailed cross-sectional view of one of thestilt journals234.) Ends of the stilts (162) affix in thesejournals234 to be supported to thebaseplate200.
• For its part, thebottom plate240 as shown inFIGS. 4C-4D of thebottom assembly220 fits below thecomposite core body250 and can affix thereto using fasteners and other means. (An isolated perspective view of thebottom plate240 is provided inFIG. 9.)Openings242 in thebottom plate240 are provided for attaching to thestilt journals234. The skin elements222 fit around the sides of thecomposite core body250 and can act as protection in general.
• If given an overall rectangular configuration, thebaseplate200 can have a width W of about 42-in. and a length L of about 92-in., giving a surface area of about 3864-sq in. A circular shape for thebaseplate200 may have dimensions for a comparable area. Additionally, thebaseplate200 can have a height H of about 12-in. and can weigh approximately 2500-lbs. in one implementation. Thus, thebaseplate200 can have a weight approximately 38% less than the weight of the conventional prior art baseplate. Yet, thebaseplate200 can have a much greater stiffness (almost 4 times greater) than a conventional baseplate as detailed below. However, these dimensions are only exemplary, and the disclosedbaseplate200 can have other dimensions depending on the implementation.
• C. Composite Body
• FIGS. 5A-5B show thecomposite core body250 of the disclosed baseplate (200) in perspective and bottom views. As noted above, thecomposite core body250 is composed of a composite material. Various types of materials can be used. Preferably, thecore body250 is composed of a carbon fiber material. The resin used, the type of weave, the strength to weight ratio, and other parameters for the carbon fiber material can be configured for a particular implementation and depend on the particulars of the carbon fiber manufacturing technology employed. The carbon fiber composite material for thecore body250 can withstand compression well, which is suitable for the vibrator's vibrating motion of imparting force into the ground. The carbon fiber material may not handle shear or friction forces very well so that the construction of thebaseplate200 and thecore body250 seek to mitigate such issues.
• As shown inFIG. 5A, thecore body250 has atop surface component260 and abottom surface component270 that are preferably separately formed and then joined together during assembly. In one embodiment, bothcomponents260/270 are composed of composite material, such as having carbon fiber. Alternatively, one of thecomponents260/270, such astop component260, can be composed of a different material, including another composite or even metal.
• Thetop surface component260 has a smooth face262 against which the top plate (210) positions. The top plate (210) can simply rest against or can affix to the smooth face262 using an appropriate fastening mechanism, such as epoxy, fasteners, or the like. A central opening266 is provided for the central piston journal (236), and surrounding openings264 are provided for the stilt journals (234). Opposing edges of thetop surface component260 form shelves268 for extending the top surface of thebaseplate200 beyond its footprint as described previously.Gussets265 can extend down from the face262 to sidewalls263 to which the face262 is connected.
• Thebottom surface component270 defines a circumference and has a bottom face272 as shown inFIG. 5B to which the baseplate's bottom plate (240) affixes for imparting force into the ground. As discussed herein, having a round interface can be beneficial in supporting the reaction mass (150) and handling bending and shear stresses with thebaseplate200, among other benefits.
• The internal structure of thecore body250 is illustrated in the top and bottom cross-sectional views ofFIGS. 6A-6B respectively. As noted previously, thetop surface component260 has thesidewall263 as shown inFIG. 6A. Thesidewall263 fits around portion of thebottom surface component270 when joined together. Thegussets265 extend from opposing ends of thesidewall263 for supporting to the top face262 of thetop surface component260.
• Thebottom surface component270 has a central structure272 with openings274 and276 for the stilt journals (234) and the piston journal (236). A lattice structure280 extends around this central structure272 and includes main or radial ribs282 interconnected by circumferential or interconnecting ribs284 and definingpockets286. This lattice structure280 increases the stiffness of thecore body250 and inhibits transverse bending.
• As shown, the lattice structure280 is preferably round so that the main ribs282 extend radially and the interconnecting ribs284 extend circumferentially. If thebaseplate200 has a different shape, such as rectangular, then the main ribs282 may extend longitudinally while the interconnecting ribs284 extend laterally. These and other variations are possible depending on the overall shape of thebaseplate200.
• D. Operation of Baseplate with Composite Body
• During operation, the contact area of a given baseplate changes between downward strokes and upward strokes. The typical prior art baseplate such as shown inFIGS. 2A-2C, which is rectangular, has downward forces on the ends as the piston provides the up and down force in the center. This movement tends to decouple the prior art baseplate from the ground, causing inefficient energy transmission.
• Ideally, a baseplate used on a seismic source can uniformly distribute force imparted from the reaction mass to the ground. To assist with such uniformity, the disclosedbaseplate200 is substantially circular having a round footprint for engaging the ground. Being symmetric, the disclosedbaseplate200 can more evenly distribute the force and avoid some of the decoupling that reduces energy transmission.
• Thesymmetric baseplate200 can produce 2^ndand 4^thorder harmonics. The stiffness of composite carbon fiber material of thecore body250 can help distribute the applied force for the ground force of the vibrator (100). Additionally, using of thecomposite core body250 in thebaseplate200 can reduce the 2^ndorder harmonics due to the more even distribution of force with the up and down strokes of the vibrator (100). Moreover, the vibrator (100) can require less energy for operation because the vibrator signal will experience less attenuation.
• Other properties of thedisclose baseplate200 help improve its transmissive properties. In general, the Young's modulus, stiffness, strength, and low density of thecomposite core body250 contribute to improved transmissive properties of thebaseplate200. In particular, a structural design preferably has a higher resonant frequency relative to any vibration to which the structure is subjected. In general, the resonant frequency for a structural design can be described by the equation:
• ${\omega }_n=\sqrt{\frac{K}{M}}$
• In the context of the vibrator (100) and thebaseplate200 of interest, the resonant frequency can be described by the equation:
• ${\omega }_n=\sqrt{\frac{K}{M_{\mathrm{bp}}}}$
• Here, K is the coupling stiffness of thebaseplate200 to the ground, and M_bpis the mass of thebaseplate200. The mass M_bpof thebaseplate200 can be known, and the value for the coupling stiffness K is governed by the Young's modulus and shape geometry of thebaseplate200, which can be defined.
• In the operation of thebaseplate200, the resonant frequency would normally limit the bandwidth achievable with thebaseplate200 during use. Thus, thebaseplate200 with a higher resonant frequency would be capable of greater bandwidth than conventionally achieved. According to the resonant frequency equation for the structural design noted above, reduction of the baseplate's mass M_bpcan increase the resonant frequency as generally desired. Because thecomposite core body250 is composed of composite carbon fiber material, which can have almost ¼ of the density of steel typically used, the disclosedbaseplate200 can have improved transmissive properties and greater achievable bandwidth due to its higher resonant frequency.
• E. Alternative Baseplate
• FIGS. 11A-11B show anotherbaseplate300 according to the present disclosure. Thebaseplate300 has acomposite body350,shelves310, stands320, and abottom plate340. Again, thecomposite body350 is composed of a composite material. Although various types of materials can be used, thebody350 is again preferably composed of a carbon fiber material.
• Thecomposite body350, which is shown in isolated view inFIG. 11 B, has acentral hub370 defining a central opening for a piston journal362. Surrounding openings holdstilt journals364. Extending out from thecentral hub370, thebody350 has alattice structure380 having radial ribs382 and circumferential ribs384 interconnecting them and defining pockets386. The outside circumference of thebody350 has anouter rim388.
• As shown inFIG. 11A, thebottom plate340 affixes to the bottom of thebody350. Thebottom plate340 can be composed of metal or the like and can attach to the flat bottom of thebody350 with fasteners or the like. The top of thebody350 can slope downward from thecentral hub370 to therim388.
• As shown inFIG. 11A, affixed on two ends of therim388 areshelves310 for supporting the isolators (140), shock absorbers (142), and tension members (144) of the vibrator (100), which are not shown but are described earlier.Gussets315 can support theshelves310 on sidewalls affixed to the body'srim388. Theshelves310 andgussets315 can be composed of composite material and can affix to the composite body using techniques available in the art. Alternatively, theshelves310 andgussets315 can be composed of metal.
• Offset from theshelves310, two stands320 fit in pockets376 of the body'slattice380. These stands320 accommodate the isolators (146) for the reaction mass (150), which are not shown but are described earlier. To enclose thecomposite body350 and other elements, the outside of thebaseplate200 can have various skin elements (not shown).
• Although the disclosedvibrator100 ofFIGS. 3A-3D has been described as having a hydraulically actuatedreaction mass150, those skilled in the art will appreciate that the teachings of the present disclosure can be applied to other types of actuators for reciprocating a reaction mass. In general, therefore, the disclosedvibrator100 can reciprocate areaction mass150 using a linear induction motor, a linear synchronous motor, a controlled hydraulic actuator, or any other actuator used in the art. Either way, thevibrator100 can use any type of actuator to impart energy into the ground with the disclosedbaseplate200.
• In addition to vibrating vertically to impart compression waves (“P-Waves”), the disclosedvibrator100 can also produce seismic shear waves (“S-Waves”). Moreover, the present disclosure has focused on a single axis seismic source for brevity and without limiting the scope of the disclosure. Those skilled in the art would recognize that a multi-axis vibratory source capable of imparting both P and S waves into the earth can be configured according to the present disclosure. Details related to coupling the disclosedvibrator100 to the ground and details related to other actuators for the disclosedvibrator100 can be found in U.S. Pat. Pub. Nos. 2007/0250269, 2007/0240930, and 2009/0073807, which are incorporated herein by reference.
• Although thebaseplate200/300 with thecomposite body250/350 is described as being circular or round, it will be appreciated with the benefit of the present disclosure that a comparable structure of the disclosedbaseplate200/300 can be applied to a square, rectangular, polygonal, or other shape for a vibrator's baseplate according to the present disclosure. For example, the teachings of the present disclosure with respect to the internalcomposite body250 ofFIGS. 5A through 6B can be applied to a rectangular or other shaped baseplate for a vibrator.
• As another example, a baseplate according to the present disclosure can have a shape and components similar to theconventional baseplate20 ofFIGS. 2A-2C. As shown inFIGS. 12A-12B, for example, anothercomposite baseplate400 is shown in exploded and exposed views. The overall shape of thisbaseplate400 is similar to that disclosed in U.S. Pat. Pub. No. 2010/0276224, which is incorporated herein by reference in its entirety.
• Thebaseplate400 has atop plate410, abottom assembly420, and acore body430. Thecore body430 fits into thebottom assembly420, and thetop plate410 disposes on thecore body430 to form thebaseplate400.FIG. 12C shows an exploded view of thecore body430 of thecomposite baseplate400.FIGS. 12D-12E show longitudinal and lateral sectional view of the composite baseplate.
• Looking at thetop plate410, thetop plate410 defines various openings for flexibility and hasreinforcement pads411 with stilt mount holes415 and isolator mount recesses417. The mount holes415 allow the stilts (not shown) of a vibrator to couple to stilt mounts413 disposed in thecore body430. The mount recesses417 hold isolators (not shown) for the vibrator's reaction mass (not shown). Corners of thetop plate410 extend out from the sides of thebaseplate400 and have retainingledges412 for the additional isolators (not shown) of the vibrator's frame (not shown). Finally, thetop plate410 can have other features, such as hangers (not shown) for tension members (not shown) and reinforcement pads (not shown) for pistons (not shown) typically used.
• As best shown inFIG. 12A, thebottom assembly420 has abottom plate422 withend walls424 andlong sidewalls426 extending upward around the plate's edges.Isolator shelves428 andgussets428′ extend from the bottom assembly'slong sidewalls426 and support the top surface's extending corners for the isolators (not shown). Lower ends of themounts413 can fit in holes in thebottom plate422.
• For its part, thecore body430 best shown inFIG. 12C can have bottom, side, end, and topexterior sheeting432,434,436, and438 to hold together the core body's internal components. One or more elements of exterior sheeting may not be needed. The stilt mounts413 fit in openings in the bottom exterior sheeting orshear panel432. Themounts413 are also exposed above the top exterior sheeting orshear panel438 and align with the mount holes415 in thetop plate410. Thesheeting434 and436 can be stiffener beams providing stiffness to thecore body430.
• Internally, as shown inFIGS. 12B-12E, thecore body430 has longitudinal ribs or beams440 that run longitudinally along the baseplate's length. Fourbeams440 are shown, but more or less could be used depending on the implementation. Interconnecting spacers orribs450 position laterally between thebeams440 and along thelong cap walls426 of thebottom assembly420. The stilt mounts413 position between inner pairs of thebeams440 at the central structure of thecore body430.
• Thebeams440 can be hollow or solid tubes with rectangular cross-sections, or thebeams440 can be I-beams or other components. As can be seen inFIGS. 12C and 12E, thebeams440 can be sandwiched between spacer strips orstiffeners442. To provide increased stiffness, thebeams440 can have an increased height, but the particular height used depends on the stiffness desired and the material used. To maintain weight and stiffness for thebeams440 when hollow, the wall thickness of thebeams440 can be appropriately configured, and the actually thickness can depend on the desired stiffness and weight of thebaseplate400 as well as the material used for thebeams440.
• Depending on the implementation, all or at least a part of thebaseplate400 can be composed of a composite material. For example, thelongitudinal beams440 can be composed of a composite material having carbon fiber or the like. Thebeams440 may or may not be hollow in such an arrangement. The interconnectingribs450 positioned between thebeams440 can be composed of composite material or metal and can be separate or integrated into thebeams440. In fact, theentire core body430 can be composed of composite material.
• Additionally, theexterior sheeting432,434,436, and438 of thecore body430 can be composed of metal. Likewise, thetop plate410 and thebottom assembly420 can be composed of metal. As will be appreciated with the benefit of the present disclosure, however, thebeams440 are preferably made of a composite material, whereas any of the other components (e.g.,top plate410,bottom assembly420,ribs450, mounts413, etc.) can be composed of metal. Dimensions and weight of thebaseplate400 can be comparable to the dimensions and weight typically used on existing baseplates so thebaseplate400 can be roughly 10-inches high, 42-inches wide, and 96-inches long and may have a weight in excess of 4000-lbs. depending on the implementation.
• The foregoing description of preferred and other embodiments is not intended to limit or restrict the scope or applicability of the inventive concepts conceived of by the Applicants. In exchange for disclosing the inventive concepts contained herein, the Applicants desire all patent rights afforded by the appended claims.
• Therefore, it is intended that the appended claims include all modifications and alterations to the full extent that they come within the scope of the following claims or the equivalents thereof.

Claims (31)

What is claimed is:

1. A seismic vibrator, comprising:

a baseplate at least partially composed of a composite material;

a mass movably disposed relative to the baseplate and imparting vibrational energy thereto;

an actuator coupled to the mass and moving the mass relative to the baseplate; and

a controller communicatively coupled to the actuator and controlling operation of the actuator.

2. The vibrator ofclaim 1, wherein the composite material comprises carbon fiber.

3. The vibrator ofclaim 1, wherein the baseplate comprises a core body composed of the composite material.

4. The vibrator ofclaim 3, wherein the core body comprises:

a bottom surface having a round perimeter, and

a top surface having a rectangular perimeter with shelves extending beyond the round perimeter of the bottom surface.

5. The vibrator ofclaim 3, wherein the baseplate comprises a top plate disposed on a top surface of the core body.

6. The vibrator ofclaim 5, wherein the top plate is composed of a metallic material.

7. The vibrator ofclaim 5, comprising first isolators disposed on the top plate and isolating the mass and the baseplate.

8. The vibrator ofclaim 5, further comprising:

a frame supporting the baseplate; and

second isolators disposed on the top plate and isolating the frame and the baseplate.

9. The vibrator ofclaim 8, further comprising piston members disposed on the top plate between the frame and the baseplate.

10. The vibrator ofclaim 8, further comprising tension members disposed on the top plate between the frame and the baseplate.

11. The vibrator ofclaim 3, wherein the baseplate comprises a central mount disposed on a top surface of the core body; and wherein the mass comprises stilts supporting the mass on the central mount.

12. The vibrator ofclaim 11, wherein the baseplate comprises first journals disposed in the core body and coupled to the stilts.

13. The vibrator ofclaim 11, wherein the actuator comprises a piston disposed through the mass; and wherein the baseplate comprises a second journal disposed through the core body and coupled to the piston.

14. The vibrator ofclaim 3, wherein the baseplate comprises a bottom plate disposed on a bottom surface of the core body.

15. The vibrator ofclaim 14, wherein bottom plate is composed of a metallic material.

16. The vibrator ofclaim 14, wherein the bottom plate comprises sidewalls extending around sides of the core body.

17. The vibrator ofclaim 1, wherein the baseplate comprises:

a top component having a top surface and an outer wall extending therefrom; and

a bottom component having a bottom surface and an inner wall extending therefrom,

wherein the top component connects on the bottom component with the outer wall fitting around the inner wall.

18. The vibrator ofclaim 1, wherein the baseplate comprises:

a central structure; and

a lattice structure surrounding the central structure, the lattice structure having main ribs extending from the central structure and having interconnecting ribs interconnecting the main ribs.

19. The vibrator ofclaim 1, wherein the main ribs extend radially from the central structure, and wherein the interconnecting ribs extend circumferentially between the main ribs.

20. The vibrator ofclaim 1, wherein the controller comprises a sensor coupled to motion of the baseplate and detecting signals indicative of acceleration imparted to the baseplate, wherein the controller controls the actuator based at least in part on the signals from the sensor.

21. A baseplate for a seismic vibrator having a mass component, an actuator component, and a frame component, the baseplate comprising:

a core body disposed on the seismic vibrator and imparting energy to the ground, the core body composed of a composite material and comprising:

a central structure to which the mass and actuator components of the seismic vibrator couple; and

a lattice structure surrounding the central structure, the lattice structure having main ribs extending from the central structure and having interconnecting ribs interconnecting the main ribs.

22. The baseplate ofclaim 21, further comprising a top plate disposed on a top surface of the core body, the top plate supporting the frame component of the vibrator.

23. The baseplate ofclaim 22, wherein the top plate comprises a metallic material.

24. The baseplate ofclaim 21, further comprising a bottom plate disposed on a bottom surface of the core body.

25. The baseplate ofclaim 24, wherein the bottom plate comprises a metallic material.

26. The baseplate ofclaim 21, wherein the central structure comprises a plurality of journals disposed therein to which the mass and actuator components couple.

27. The baseplate ofclaim 21, wherein the main ribs extend radially from the central structure, and wherein the interconnecting ribs extend circumferentially between the main ribs.

28. A baseplate for a seismic vibrator having a mass component, an actuator component, and a frame component, the baseplate comprising:

a core body composed of a composite material and having a top and a bottom;

one or more upper plates disposed on the top of the core body and supporting the mass component, the actuator component, and the frame component; and

a bottom plate disposed on the bottom of the core body.

29. The baseplate ofclaim 28, wherein the one or more upper plates comprise a top plate supporting the frame component.

30. The baseplate ofclaim 28, wherein the one or more upper plates comprises a central mount supporting the mass and actuator components.

31. The baseplate ofclaim 28, wherein the core body comprises a plurality of journals disposed therein to which the mass and actuator components couple.

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