Vibroseis device driven by linear motor

Abstract

The invention relates to the technical field of seismic exploration equipment, and provides a controllable seismic source device driven by a linear motor, which comprises a touch foundation plate and a guide rail supporting column vertically mounted on the touch foundation plate, an elastic piece connected to the top in the guide rail supporting column, and a connecting rod in the middle of the connecting piece extending into a top plate of the guide rail supporting column to be connected with the elastic piece. The two ends of the connecting piece are connected with the counter weights arranged on the two sides of the guide rail supporting column, rails of the linear motor are installed on the two sides, corresponding to the counter weights, of the guide rail supporting column, permanent magnet sets evenly arranged in the length direction are embedded in the rails, and driving coils of the linear motor are connected to the counter weights relative to the rails. The counter weight is driven by the driving coil to reciprocate up and down along the track, and generated excitation counter force is transmitted to the ground touching base plate through the connecting piece, the elastic piece and the guide rail supporting column to drive the ground touching base plate to move up and down on the ground to generate seismic waves. According to the invention, 2Hz low-frequency output of the vibroseis is ensured, and the problems of huge size and poor portability of a traditional vibroseis are solved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of seismic exploration, and particularly relates to a controllable source device driven by a linear motor. BACKGROUND

[0002] In seismic exploration, in order to obtain underground structure and stratum attribute information, a source as a key equipment for energy excitation plays a crucial role. The traditional seismic exploration mostly adopts a dynamite source mode, but due to the problems of high safety risk, great environmental impact and uncontrollable excitation, the dynamite source mode has been gradually replaced by a controllable source in recent years. The controllable source is a device capable of repeatedly generating seismic waves through a mechanical device, and can generate an excitation signal of a certain frequency and waveform according to preset parameters, and has the advantages of strong controllability, good repeatability, environmental protection and safety.

[0003] At present, the mainstream controllable source widely used in the field of oil and gas exploration is a hydraulic drive type, which carries a hydraulic system through a large vehicle, drives a vibrator into contact with the ground and excites seismic waves into the underground. The hydraulic controllable source can output a large excitation force, is suitable for large-scale land seismic exploration projects, and has mature technology and rich engineering experience. However, the hydraulic system has a complex structure, a large overall size, high requirements for construction site conditions, and certain flexibility limitations and portability limitations when operating in complex terrain or inconvenient traffic areas. In addition, realizing stable excitation of low frequency (especially below 3Hz) still faces certain technical challenges.

[0004] In recent years, with the increasing importance of low-frequency seismic signals in oil and gas exploration, especially in the application of direct hydrocarbon indication (DHI) and low-frequency ghost, higher requirements are put forward for the controllable source capable of stably outputting low-frequency signals. Research shows that seismic excitation signals below 3Hz have a significant effect on improving oil and gas identification accuracy. Therefore, developing a new controllable source with low-frequency excitation capability and being more convenient to deploy and operate has become an important direction of current technical development. SUMMARY

[0005] In view of the above technical problems, the present application provides a controllable source device driven by a linear motor, which solves the design and manufacturing difficulties caused by the increase of the overall mass and the specifications of the parts of the controllable source when realizing low-frequency excitation.

[0006] The purpose of the present application is achieved by the following technical solutions: The application discloses a controllable vibrator device driven by a linear motor, which comprises a ground-contacting base plate, a guide rail support column, an elastic element, a connecting element, a linear motor and a counterweight, the guide rail support column is vertically installed on the ground-contacting base plate, a groove for installing the elastic element is formed in the top plate of the guide rail support column, the middle connecting rod of the connecting element extends into the top plate of the guide rail support column to connect the elastic element, the connecting element is symmetrically connected with the counterweight arranged on the two sides of the guide rail support column, the track of the linear motor is installed on the two sides of the guide rail support column corresponding to the counterweight, a plurality of permanent magnets arranged in the length direction are embedded in the track, the driving coil of the linear motor is connected to the counterweight relative to the track, and the driving coil drives the counterweight to reciprocate up and down along the track on the guide rail support column during operation, the generated exciting counterforce is transmitted to the ground-contacting base plate through the connecting element, the elastic element and the guide rail support column, the ground-contacting base plate is driven to move up and down on the ground, and the seismic wave is generated.

[0007] Further, the top plate of the guide rail support column is connected with a hanger, the top plate is provided with a through hole into which the middle connecting rod of the connecting element extends, and the bottom of the column body is provided with a bottom plate connected with the ground-contacting base plate.

[0008] Further, the connecting element comprises a horizontal rod, vertical rods connected with the counterweight are arranged at the two ends of the horizontal rod, and a middle connecting rod is arranged in the middle of the horizontal rod between the two vertical rods, and the bottom end of the middle connecting rod is provided with a connecting plate connected with the elastic element.

[0009] Further, the outer diameter of the connecting plate is greater than the diameter of the through hole formed in the top plate of the guide rail support column, so that the connecting plate can move up and down in the groove of the guide rail support column along with the elastic element.

[0010] Further, the counterweight comprises a dead weight and a load which are detachably connected, and the driving coil of the linear motor and the connecting element are connected to the dead weight.

[0011] Further, the top of the dead weight and the hanger and the bottom of the dead weight and the guide rail support column are respectively connected with a guide limiting device.

[0012] Further, the guide limiting device is a leaf spring which is arranged at an angle of 90° by fixing a horizontally arranged spring steel sheet and a vertically arranged spring steel sheet to each other, the horizontally arranged spring steel sheet is connected with the hanger or the guide rail support column, the vertically arranged spring steel sheet is connected with the dead weight, the dead weight is guided to move in the vertical direction through the vertically arranged spring steel sheet, and the horizontally arranged spring steel sheet limits the non-vertical movement of the dead weight.

[0013] Further, during transportation, the ground-contacting base plate and the dead weight are connected through fasteners.

[0014] Further, the elastic element is an air spring, and the upper and lower end faces of the air spring are flat.

[0015] Further, a limiting block is arranged on the top surface of the ground-contacting base plate below the dead weight hammer, and the limiting block is located 50-55mm below the limit position of the movement stroke of the dead weight hammer to limit the impact of the dead weight hammer on the ground-contacting base plate.

[0016] The present application has the following advantages: The present application cancels the complex hydraulic system in the traditional hydraulic vibrator, directly drives the vibration structure by using the linear motor, has a more compact overall structure, is almost not limited by the traditional transmission path, has a fast response speed and a high control precision, and compared with the traditional hydraulic vibrator, the system is more simplified, is more convenient to maintain, and especially can realize stable vibration in the 2Hz low frequency band, and has a more obvious low-frequency excitation advantage. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a front view of the present application; Figure 2 is a side view of the present application; Figure 1 Figure 3 is a perspective view of the present application; Figure 4 is a schematic view of the working principle of the present application.

[0018] In the figure, 1 is a lifting ring, 101 is a lifting frame, 2 is a leaf spring, 3 is a connecting piece, 31 is a horizontal rod, 32 is a vertical rod, 33 is a middle connecting rod, 4 is a track, 5 is a driving coil, 6 is a fastener, 7 is a ground-contacting base plate, 8 is a dead weight hammer, 9 is a limiting block, 10 is an elastic piece, 11 is a guide rail support column, 111 is a column body, 112 is a groove, 113 is a top plate, 114 is a bottom plate, and 12 is a load. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical scheme and advantages of the present application more clear and explicit, the present application is further described in detail below by combining with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application, and are not used to limit the present application.

[0020] In order to make the figure simple, only the parts related to the present application are schematically shown in each figure, and they do not represent the actual structure of the product.

[0021] In this paper, it should be noted that unless otherwise specified and limited, the terms "mounting", "connecting" and "connecting" should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected, it can be mechanically connected, or it can be electrically connected, it can be directly connected, or it can be indirectly connected through an intermediate medium, and it can be the communication inside two elements. For ordinary skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.​

[0022] Example: The present invention provides a land-based controllable seismic source driven by a linear synchronous motor, which has the advantages of compact structure, rapid response and high excitation accuracy, and can realize the excitation of low-frequency, controllable seismic wave signals on land.

[0023] like Figures 1-4 As shown, the present invention discloses a controllable vibration source device driven by a linear motor, comprising a ground contact plate 7, a guide rail support column 11, an elastic element 10, a connector 3, a linear motor, and counterweights. The guide rail support column 11 is vertically mounted on the ground contact plate 7. A groove 112 for mounting the elastic element 10 is formed below the top plate 113 of the guide rail support column 11. The connecting rod 33 in the middle of the connector 3 extends into the top plate 113 of the guide rail support column 11 and connects to the elastic element 10. The two ends of the connector 3 are symmetrically connected to counterweights placed on both sides of the guide rail support column 11. The track 4 of the machine is installed on both sides of the counterweight corresponding to the guide rail support column 11. The track 4 is embedded with a group of permanent magnets evenly arranged along the length direction. The drive coil 5 of the linear motor is connected to the counterweight relative to the track 4. When working, the drive coil 5 of the linear motor drives the counterweight to move up and down along the track 4 on the guide rail support column 11, generating an excitation reaction force. This excitation reaction force is transmitted to the ground contact plate 7 through the connector 3, the elastic element 10, and the guide rail support column 11, causing the ground contact plate 7 to move up and down on the ground and generate seismic waves.

[0024] The top plate 113 of the guide rail support column 11 is connected to the hanger 101. The top plate 113 has a through hole through which the connecting rod 33 of the connector 3 extends. The bottom of the column 111 is provided with a bottom plate 114 connected to the ground plate 7. The column 111 is a square column, but it can also be a cylindrical column. In this example, the column 111 is a square column.

[0025] The connector 3 includes a horizontal rod 31, vertical rods 32 for connecting counterweights are provided at both ends of the horizontal rod 31, a middle connecting rod 33 is provided in the middle of the horizontal rod 31 between the two vertical rods 32, and a connecting plate for connecting elastic member 10 is provided at the bottom end of the middle connecting rod 33.

[0026] The outer diameter of the connecting plate is larger than the diameter of the through hole on the top plate 113 of the guide rail support column 11. This ensures that the connecting plate moves up and down within the groove 112 of the guide rail support column 11 along with the elastic element 10.

[0027] The connecting plate is in planar contact with the elastic element 10. The gravity of the unloaded hammer 8 is guided to the elastic element 10 by the connecting member 3, so that the weight of the counterweight is effectively transferred to the elastic element 10. During operation, this structure ensures that the configuration moves only in the vertical direction, avoids off-center loading, and extends the service life of the elastic element 10.

[0028] The counterweight comprises a detachable connecting empty load weight 8 and load 12, and the driving coil 5 of the linear motor and the connecting piece 3 are connected on the empty load weight 8. The empty load weight 8 connected with the load 12 reciprocates along the vertical direction under the action of the driving coil 5 of the linear motor, and the reaction force generated by the mass and acceleration thereof excites the seismic wave. In the process of dismounting and mounting, the empty load weight 8 and the load 12 are tightened and compacted by screws, and can be flexibly mounted or dismounted according to the operation requirements, so as to adjust the overall mass of the controllable seismic source counterweight, thereby meeting the requirements of different excitation intensities, and facilitating the lightweight treatment of the equipment in the transportation process.

[0029] Preferably, the exciter of the controllable seismic source comprises two identical linear motors, each of which comprises a track 4, a driving coil 5 and a permanent magnet group, wherein the tracks 4 of the two linear motors are installed on the opposite sides of the guide rail support column 11, the driving coils 5 are provided with two groups corresponding to the tracks 4 and are connected on the empty load weight 8, the permanent magnet group is embedded in the track 4 in the length direction, the driving coil 5 is connected with the external control system, when the driving coil 5 is electrified, the changing current interacts with the permanent magnet in the track 4 to generate a changing magnetic field, a continuous and stable magnetic field is formed by electromagnetic force, and the empty load weight 8 and the load 12 reciprocate along the track 4; the track 4 provides accurate linear guidance for the empty load weight 8 and the load 12, so that they stably reciprocate along the track 4 during excitation.

[0030] The tracks 4 and the driving coils 5 of the two linear motors are symmetrically installed on the two sides of the central axis of the guide rail support column 11, and the output forces of the two are equal in size and consistent in direction during work, so that the resultant force is formed in the vertical direction.

[0031] The top of the empty load weight 8 and the hanger 101, and the empty load weight 8 and the guide rail support column 11 are respectively connected with a guide limiting device. The guide limiting device is a leaf spring 2, which is arranged at an angle of 90° by fixing the horizontally arranged spring steel sheet and the vertically arranged spring steel sheet through the connecting piece, the horizontally arranged spring steel sheet is connected with the hanger 101 or the guide rail support column 11, and the vertically arranged spring steel sheet is connected with the empty load weight 8. During work, the vertically arranged spring steel sheet guides the empty load weight 8 to move along the vertical direction, and the horizontally arranged spring steel sheet limits the non-vertical movement of the empty load weight 8, so that the movement path of the empty load weight 8 is strictly limited in the vertical direction, thereby improving the motion stability of the controllable seismic source and the consistency of the system response.

[0032] The elastic member 10 is an air spring, the upper and lower end faces of which are flat and connected with the connecting member 3 and the guide rail support column 11 respectively, and bears the static load of the dead weight 8 and the load 12; the main function of the air spring is to balance the gravity of the dead weight 8 or the load 12, so as to avoid the movement of the dead weight 8 being limited due to its own gravity when moving upward. Therefore, when the dead weight 8 moves relative to the guide rail support column 11, the air spring should be in a proper compression or stretching state, and since the stroke of the motor is not large, the air spring is in a small compression or stretching state.

[0033] The ground contact plate 7 is connected with the guide rail support column 11 rigidly at one end and directly contacts with the ground at the other end, and is used for supporting the whole vibration excitation system and bearing the reaction force generated by the movement of the dead weight 8 and the load 12, and transmitting the energy to the ground.

[0034] The ground contact plate 7 is connected with the guide rail support column 11 rigidly at one end and directly contacts with the ground at the other end, and is used for supporting the whole vibration excitation system and bearing the reaction force generated by the movement of the dead weight 8 and the load 12, and transmitting the energy to the ground.

[0035] In work, the dead weight 8 does not contact with the ground contact plate 7, and the load 12 and the dead weight 8 move up and down in the vertical direction, and the acceleration and the mass together generate a vibration excitation reaction force, which is transmitted to the ground contact plate 7 through the connecting member 3, the air spring and the guide rail support column 11, drives the ground contact plate 7 to move up and down on the ground, and generates seismic waves.

[0036] The limit block 9 is arranged to provide mechanical limit when the dead weight 8 is in extreme working condition or control abnormality, so as to prevent the dead weight 8 from directly impacting the ground contact plate 7 when the movement is out of control, thereby avoiding the mechanical structure being damaged and preventing the linear motor from flying, and playing a protection role, so as to avoid the movement part from running beyond the stroke and impacting or damaging the mechanical structure of the controllable seismic source.

[0037] The hanger 101 is connected with the lifting ring 1 and is used for lifting.

[0038] In transportation, the contact ground plate 7 and the empty load weight 8 are connected and fixed by the fastener 6, so that the empty load weight 8 keeps a safe distance from the ground plate, facilitating forklift transportation in use, and the fastener 6 is disassembled in the working state.

[0039] In the working process of the present application, the contact ground plate 7 is placed on the ground. First, the device is transported to the predetermined working position, and the equipment is hoisted by the lifting ring 1. In order to prevent vibration and structural damage during transportation, the fastener 6 is used to temporarily fix the empty load weight 8 and the contact ground plate 7 in the factory state. After arriving at the work site, the fastener 6 is removed, and the empty load weight 8 is released, so that it has the freedom of vertical movement.

[0040] Then, the external control system (prior art) energizes the linear motor drive coil 5. When the external control system supplies current to the drive coil 5 according to the preset sweep waveform, the drive coil 5 is subjected to Lorentz force in the magnetic field of the track 4, generating a controllable linear thrust. Since the drive coil 5 is fixedly connected with the empty load weight 8, the electromagnetic thrust directly drives the empty load weight 8 and the load 12 to reciprocate up and down, thereby realizing precise and high-response mechanical excitation, driving the entire counterweight to reciprocate up and down along the guide rail support column 11.

[0041] Since the leaf spring 2 is connected with the guide rail support column 11 and the empty load weight 8 respectively, the vertical spring steel sheet of the leaf spring 2 connected with the empty load weight 8 allows and guides the counterweight to move in the vertical direction, providing elastic recovery and motion stability; the horizontal spring steel sheet connected with the guide rail support column resists lateral displacement, limiting the left-right / forward-backward swing of the counterweight, ensuring the directionality of the motion; during the motion, the leaf spring 2 plays a vertical guiding and horizontal restraining role, suppressing the slight disturbance in the non-vertical direction, so that the counterweight always maintains a stable and symmetrical vertical excitation path, further improving the direction consistency and repeatability of the excited signal, and ensuring the stable excitation quality of the seismic wave.

[0042] At the same time, the static load of the counterweight is transmitted to the air spring through the connecting piece 3, and the air spring bears its static support function and provides partial buffering and balance for the counterweight motion through the elastic recovery force, prolonging its service life.

[0043] During the excitation process, the acceleration of the empty load weight 8 and the load 12 and the mass together generate an excitation reaction force, which is transmitted to the ground by the contact ground plate 7, forming a stable seismic wave signal. Since the contact ground plate 7 is connected with the entire device of the present application through the guide rail support column 11 and is tightly coupled with the ground, it ensures efficient energy transmission. In the design, the present application discards the traditional compression mass block, and increases the weight of the contact ground plate 7 by using high-density materials to ensure the ground coupling effect. While reducing the number of elements that may distort the signal, the coupling between the contact ground plate 7 and the ground is as much as possible not affected.

[0044] To prevent the occurrence of flying car or electromagnetic control failure in extreme cases, the limiting block 9 is arranged above the grounding base plate 7, which can provide mechanical limiting when the counterweight abnormally displaces, avoid impacting the track 4, and ensure the safety of the structure.

[0045] After the completion of the seismic exploration operation, the power supply is turned off, the driving coil 5 stops energization, and the counterweight slowly resets to the lowest position under the action of gravity. Alternatively, the fastener 6 is reinstalled to lock the empty load weight 8, facilitating the transportation or transfer of the device.

[0046] In addition, in order to meet the requirements of the weight and size of the device during transportation, the load 12 can be disassembled according to the actual operation arrangement. The load 12 is detachably connected to the empty load weight 8 through bolts. Before the device is transferred, the operator can remove the load 12 to reduce the overall weight and improve the convenience and safety of hoisting and vehicle transportation. After arriving at the new operation point, the load 12 is reinstalled on the empty load weight 8 according to the required excitation energy to adjust the excitation mass and ensure that the performance of the seismic source meets the demand of the new site geological conditions.

[0047] The structure of the present application uses a linear motor to directly drive the up-and-down vibration of the counterweight, eliminating the traditional hydraulic system. The structure of the present application is more compact, has fast response speed, and high control precision. The detachable load 12 adjusts the mass of the counterweight to adapt to the excitation requirements under different geological conditions. At the same time, the present application can realize stable excitation in the low frequency band of 2Hz, has strong controllability and frequency adaptability, and is particularly suitable for the application of low-frequency seismic waves in oil and gas resource exploration, and has broad popularization value.

[0048] Preferably, two symmetrical linear motors are arranged in the exciter, and the track 4 and the driving coil 5 are distributed on both sides of the guide rail support column 11. Under the control and coordination of the two linear motors, the driving forces output by the two linear motors are equal and have the same direction, forming a resultant force to realize balanced excitation, improve signal quality, and reduce the risk of mechanical deviation.

[0049] The components not described in detail in the present application are conventional existing technologies, and will not be described here.

[0050] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A linear motor driven seismic source device, characterized by: The utility model provides a kind of seismic wave generator, including ground contact base plate (7), guide rail support column (11), elastic element (10), connecting piece (3), linear motor and counterweight, guide rail support column (11) is vertically installed on ground contact base plate (7), recess (112) of installing elastic element (10) is opened in the top plate (113) of guide rail support column (11), the middle connecting rod (33) of connecting piece (3) is inserted into the top plate (113) of guide rail support column (11) and connects elastic element (10), connecting piece (3) both ends symmetrically connect the counterweight placed in the both sides of guide rail support column (11), the track (4) of linear motor is installed in the both sides of guide rail support column (11) corresponding counterweight, permanent magnet group is embedded in track (4) inside along the length direction even arrangement, the driving coil (5) of linear motor is connected on counterweight relative to track (4), when working, driving coil (5) of linear motor drives counterweight to reciprocate along track (4) on guide rail support column (11) up and down, and the exciting vibration counterforce generated is transmitted to ground contact base plate (7) by connecting piece (3), elastic element (10), guide rail support column (11), drives ground contact base plate (7) to move on ground up and down, generates seismic wave.

2. The linear motor driven seismic source apparatus according to claim 1, wherein: The top plate of the guide rail support column (11) is connected to a hanger (101), and the top plate (113) is provided with a through hole into which the middle connecting rod (33) of the connecting piece (3) extends, and the bottom of the column body (111) is provided with a bottom plate (114) connected to the ground contact base plate (7).

3. The variable source device driven by linear motor of claim 2, wherein: The connecting piece (3) comprises a transverse rod (31), vertical rods (32) connected to the counterweight are arranged at both ends of the transverse rod (31), and a middle connecting rod (33) is arranged at the middle of the transverse rod (31) between the two vertical rods (32), and the bottom end of the middle connecting rod (33) is provided with a connecting plate connected to the elastic element (10).

4. A variable source device driven by a linear motor according to claim 3, characterized in that: The outer diameter of the connecting plate is greater than the diameter of the through hole provided in the top plate (113) of the guide rail support column (11), so that the connecting plate can move up and down in the recess (112) of the guide rail support column (11) along with the elastic element (10).

5. The vibrator apparatus of claim 2, wherein: The counterweight comprises an empty load weight (8) and a load (12) which are detachably connected, and the driving coil (5) of the linear motor and the connecting piece (3) are connected to the empty load weight (8).

6. A variable source device driven by a linear motor according to claim 5, characterized in that: Guide limiting devices are respectively connected between the top of the empty load weight (8) and the hanger (101) and between the bottom of the empty load weight (8) and the guide rail support column (11).

7. The variable- source device of claim 6, wherein: The guide limiting device is a leaf spring (2) which is arranged at an angle of 90° by fixing a horizontally arranged spring steel sheet and a vertically arranged spring steel sheet to each other, the horizontally arranged spring steel sheet is connected to the hanger (101) or the guide rail support column (11), the vertically arranged spring steel sheet is connected to the empty load weight (8), the vertically arranged spring steel sheet guides the empty load weight (8) to move in the vertical direction, and the horizontally arranged spring steel sheet limits the non-vertical movement of the empty load weight (8).

8. A variable source device driven by a linear motor according to claim 5 or 6, characterized in that: During transportation, the ground contact base plate (7) and the empty load weight (8) are connected by a fastener (6).

9. The linear motor driven seismic source of claim 1, wherein: The elastic element (10) is an air spring, and the upper and lower end faces of the air spring are flat.

10. The linear motor driven seismic source of claim 5, wherein: A limit block (9) is further arranged on the top surface of the ground contact base plate (7) below the empty load weight (8), and the limit block (9) is located 50-55 mm below the limit position of the movement stroke of the empty load weight (8), so as to limit the impact of the empty load weight (8) on the ground contact base plate (7).

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