A linear motor driven vibratory source apparatus

Abstract

The present application relates to the technical field of seismic exploration equipment, and proposes a controllable source device driven by a linear motor, which comprises a ground-contacting base plate and a vertical guide rail support column installed on the ground-contacting base plate, an elastic member connected to the top of the guide rail support column, a connecting rod of a connecting member extending into the elastic member of the top plate of the guide rail support column, counterweights connected to both ends of the connecting member and placed on both sides of the guide rail support column, a track of the linear motor installed on both sides of the corresponding counterweights of the guide rail support column, a permanent magnet group uniformly arranged along the length direction embedded in the track, and drive coils of the linear motor connected to the counterweights relative to the track, wherein, during operation, the drive coils drive the counterweights to reciprocate up and down along the track, the generated exciting counterforce is transmitted to the ground-contacting base plate through the connecting member, the elastic member and the guide rail support column, the ground-contacting base plate is driven to move up and down on the ground, and seismic waves are generated. The present application ensures the 2Hz low-frequency output of the controllable source while solving the problems of large volume and poor portability of the traditional controllable source.

Description

Technical Field

[0001] This invention belongs to the field of seismic exploration technology, and in particular relates to a controllable seismic source device driven by a linear motor. Background Technology

[0002] In seismic exploration, the seismic source, as the key device for energy excitation, plays a crucial role in obtaining information about underground structures and stratigraphic properties. Traditional seismic exploration often uses explosive seismic sources, but due to high safety risks, significant environmental impact, and uncontrollable excitation, it has been gradually replaced by controlled seismic sources in recent years. A controlled seismic source is a device that can repeatedly generate seismic waves through mechanical means. It can generate excitation signals of a certain frequency and waveform according to preset parameters, and has advantages such as strong controllability, good repeatability, and environmental safety.

[0003] Currently, the mainstream controllable seismic sources widely used in oil and gas exploration are mostly hydraulically driven. These sources utilize a hydraulic system mounted on a large vehicle to drive a vibrator to contact the ground and generate seismic waves underground. Hydraulic controllable seismic sources can output large excitation forces, making them suitable for large-scale onshore seismic exploration projects. The technology is mature and has extensive engineering experience. However, hydraulic systems are complex in structure and bulky, requiring specific site conditions. Furthermore, they have limitations in flexibility and portability when operating in complex terrain or areas with poor transportation. In addition, achieving stable excitation at low frequencies (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 technologies such as direct hydrocarbon indication (DHI) and low-frequency imaging, higher demands have been placed on controllable seismic sources capable of stably outputting low-frequency signals. Studies have shown that seismic excitation signals below 3Hz have a significant effect on improving the accuracy of oil and gas identification. Therefore, developing new controllable seismic sources with low-frequency excitation capabilities that are also easier to deploy and operate has become an important direction for current technological development. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a linear motor-driven controllable vibration source device, which solves the design and manufacturing difficulties caused by the increased overall mass and component specifications when the controllable vibration source achieves low-frequency excitation.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] This invention discloses a controllable seismic source device driven by a linear motor, comprising a ground contact plate, a guide rail support column, an elastic element, a connector, a linear motor, and a counterweight. The guide rail support column is vertically mounted on the ground contact plate. A groove for mounting the elastic element is formed below the top plate of the guide rail support column. The connecting rod in the middle of the connector extends into the top plate of the guide rail support column and connects to the elastic element. The two ends of the connector are symmetrically connected to the counterweights placed on both sides of the guide rail support column. The track of the linear motor is installed on both sides of the guide rail support column corresponding to the counterweights. A group of permanent magnets evenly arranged along the length direction is embedded inside the track. The drive coil of the linear motor is connected to the counterweight relative to the track. During operation, the drive coil of the linear motor drives the counterweight to move up and down along the track on the guide rail support column. The resulting excitation reaction force is transmitted to the ground contact plate through the connector, the elastic element, and the guide rail support column, causing the ground contact plate to move up and down on the ground and generate seismic waves.

[0008] Furthermore, the top plate of the guide rail support column is connected to a hanger, and the top plate has a through hole into which the middle connecting rod of the connector extends. The bottom of the column is provided with a base plate that connects to the ground plate.

[0009] Furthermore, the connector includes a horizontal bar, vertical bars for connecting counterweights are provided at both ends of the horizontal bar, a central connecting bar is provided in the middle of the horizontal bar between the two vertical bars, and a connecting plate for connecting elastic elements is provided at the bottom end of the central connecting bar.

[0010] Furthermore, the outer diameter of the connecting plate is larger than the diameter of the through hole on the top plate of the guide rail support column. This ensures that the connecting plate moves up and down within the groove of the guide rail support column along with the elastic element.

[0011] Furthermore, the counterweight includes a detachably connected unloaded weight and a load, with a linear motor drive coil and connector connected to the unloaded weight.

[0012] Furthermore, guide and limiting devices are respectively connected between the top of the unloaded hammer and the hanger, and between the bottom of the unloaded hammer and the guide rail support column.

[0013] Furthermore, the guiding and limiting device is a leaf spring, which consists of horizontally arranged spring steel plates and vertically arranged spring steel plates fixed to each other at a 90° angle. The horizontally arranged spring steel plates are connected to the hanger or guide rail support column, and the vertically arranged spring steel plates are connected to the unloaded weight. The vertically arranged spring steel plates guide the unloaded weight to move in the vertical direction, while the horizontally arranged spring steel plates restrict the unloaded weight from moving in a non-vertical direction.

[0014] Furthermore, during transportation, the ground contact plate and the unloaded hammer are connected by fasteners.

[0015] Furthermore, the elastic element is an air spring, and the upper and lower end faces of the air spring are planes.

[0016] Furthermore, a limiting block is provided on the top surface of the ground contact plate below the unloaded hammer, and the limiting block is located 50-55mm below the extreme position of the unloaded hammer's movement stroke, thereby restricting the unloaded hammer from impacting the ground contact plate.

[0017] The beneficial effects of this invention are as follows:

[0018] This invention eliminates the complex hydraulic system in traditional hydraulic vibratory sources and adopts a linear motor to directly drive the excitation structure. The overall structure is more compact, almost unrestricted by traditional transmission paths, has a fast response speed, and high control precision. Compared with traditional hydraulic vibratory sources, the system is simpler and easier to maintain under the same excitation frequency requirements. In particular, it can achieve stable vibration in the 2Hz low-frequency range and has a more obvious advantage in low-frequency excitation. Attached Figure Description

[0019] Figure 1 This is the front view of the present invention;

[0020] Figure 2 for Figure 1 Side view;

[0021] Figure 3 This is a three-dimensional schematic diagram of the present invention;

[0022] Figure 4 This is a schematic diagram illustrating the working principle of the present invention.

[0023] In the diagram, 1 is the lifting ring, 101 is the hanger, 2 is the leaf spring, 3 is the connector, 31 is the horizontal rod, 32 is the vertical rod, 33 is the central connecting rod, 4 is the track, 5 is the drive coil, 6 is the fastener, 7 is the ground contact plate, 8 is the unloaded counterweight, 9 is the limiting block, 10 is the elastic element, 11 is the guide rail support column, 111 is the column body, 112 is the groove, 113 is the top plate, 114 is the bottom plate, and 12 is the load. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0025] To keep the drawings simple, each drawing only schematically shows the parts relevant to the invention, and they do not represent the actual structure of the product.

[0026] In this document, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] The counterweight includes a detachably connected unloaded hammer 8 and a load 12. A linear motor drive coil 5 and a connector 3 are connected to the unloaded hammer 8. Under the action of the linear motor drive coil 5, the unloaded hammer 8 connected to the load 12 reciprocates vertically, generating a reaction force through its mass and acceleration to excite seismic waves. The unloaded hammer 8 and the load 12 are tightened with screws during disassembly and installation, allowing for flexible installation or disassembly according to operational needs. This adjusts the overall mass of the controllable seismic source counterweight to meet different excitation intensity requirements and facilitates lightweight handling of the equipment during transportation.

[0034] Preferably, the vibrator of the controllable vibration source includes two identical linear motors. Each linear motor includes a track 4, a drive coil 5, and a permanent magnet assembly. The tracks 4 of the two linear motors are installed on opposite sides of the guide rail support column 11. Two sets of drive coils 5 are set corresponding to the tracks 4 and connected to the unloaded weight 8. The tracks 4 contain a set of permanent magnets evenly arranged along their length. The drive coils 5 are connected to an external control system. When the drive coils 5 are energized, they interact with the permanent magnets in the tracks 4 through changing current, generating a changing magnetic field. Through electromagnetic force, a continuous and stable magnetic field is formed, driving the unloaded weight 8 and the load 12 to reciprocate along the tracks 4. The tracks 4 provide precise linear guidance for the unloaded weight 8 and the load 12, allowing them to reciprocate smoothly along the track 4 during the vibration process.

[0035] The tracks 4 and drive coils 5 of the two linear motors are symmetrically installed on both sides of the central axis of the guide rail support column 11. When working, the output forces of the two motors are equal in magnitude and in the same direction, forming a resultant force in the vertical direction.

[0036] Guide and limiting devices are also connected between the top of the unloaded hammer 8 and the hanger 101, and between the unloaded hammer 8 and the guide rail support column 11. The guide and limiting device is a leaf spring 2, which consists of horizontally arranged spring steel plates and vertically arranged spring steel plates fixed to each other at a 90° angle by connectors. The horizontally arranged spring steel plates are connected to the hanger 101 or the guide rail support column 11, and the vertically arranged spring steel plates are connected to the unloaded hammer 8. During operation, the vertically arranged spring steel plates guide the unloaded hammer 8 to move in the vertical direction, while the horizontally arranged spring steel plates restrict the non-vertical movement of the unloaded hammer 8, strictly limiting the movement path of the unloaded hammer 8 to the vertical direction, thereby improving the motion stability of the controllable source and the consistency of the system response.

[0037] The elastic element 10 is an air spring, with its upper and lower end faces being flat. It connects to the connecting piece 3 and the guide rail support column 11, respectively, and bears the static load of the unloaded hammer 8 and the load 12. The main function of the air spring is to balance the weight of the counterweight (whether it's the unloaded hammer 8 or the load 12), preventing the unloaded hammer 8 from being restricted in its upward movement due to its own weight. Therefore, when the unloaded hammer 8 moves relative to the guide rail support column 11, the air spring should be in a suitable compressed or stretched state. Due to the small design of the motor stroke, it is in a state of slight compression or stretching.

[0038] The ground contact plate 7 adopts an existing structure. One end of the ground contact plate 7 is rigidly connected to the guide rail support column 11, and the other end is in direct contact with the ground. It is used to support the entire excitation system, bear the reaction force generated by the movement of the unloaded hammer 8 and the load 12, and transfer energy to the ground.

[0039] A limiting block 9 is also provided on the top surface of the ground contact plate 7 below the unloaded weight 8, and the limiting block 9 is located 50-55mm below the extreme position of the unloaded weight 8's movement stroke. In this example, the limiting block 9 is designed to be located 50mm below the extreme position of the unloaded weight 8's movement stroke. When the design stroke of the seismic source is ±50mm, the limiting block 9 is set at 50mm below the extreme position. The main function of the limiting block 9 is to prevent the unloaded weight 8 from impacting the ground contact plate 7, thus preventing damage to the ground contact plate 7, and mainly playing a protective role. The ground contact plate 7 is the contact medium between the seismic source system and the ground, and its main function is to efficiently and uniformly transfer the vibration energy generated by the seismic source to the ground, thereby exciting seismic waves.

[0040] During operation, the unloaded hammer 8 does not contact the ground contact plate 7. The load 12 and the unloaded hammer 8 move up and down in the vertical direction. Their acceleration and mass together generate an excitation reaction force. This excitation reaction force is transmitted to the ground contact plate 7 through the connector 3, air spring, and guide rail support column 11, causing the ground contact plate 7 to move up and down on the ground and generate seismic waves.

[0041] By setting the limit block 9, the unloaded hammer 8 provides mechanical limit in extreme working conditions or control abnormalities, preventing the unloaded hammer 8 from directly hitting the ground plate 7 when its movement is out of control, thereby avoiding damage to the mechanical structure and preventing the linear motor from running away, thus playing a protective role and preventing the moving parts from running beyond their travel range, which would cause impact or damage to the mechanical structure of the controllable vibration source of this application.

[0042] Hangers 101 are also connected to the top plate 113 of the guide rail support column 11 on both sides of the connector 3. Lifting rings 1 are connected to the hangers 101 for hoisting.

[0043] During transportation, the ground contact plate 7 and the unloaded hammer 8 are connected and fixed by fasteners 6 to maintain a safe distance between the unloaded hammer 8 and the plate, which facilitates forklift transportation during use. When in operation, the fasteners 6 are removed.

[0044] In operation, the ground contact plate 7 is placed on the ground. First, after the device is transported to the predetermined working position, it is hoisted using the lifting ring 1. To prevent vibration and structural damage during transportation, the unloaded weight 8 is temporarily fixed to the ground contact plate 7 using fasteners 6 in the factory condition. Upon arrival at the work site, the fasteners 6 are removed, releasing the unloaded weight 8 and allowing it to move freely in the vertical direction.

[0045] Then, the external control system (existing technology) energizes the linear motor drive coil 5. When the external control system supplies current to the drive coil 5 according to a preset sweep frequency waveform, the drive coil 5 is subjected to a Lorentz force in the magnetic field of the track 4, generating a linear thrust with controllable direction. Since the drive coil 5 is fixedly connected to the unloaded weight 8, this electromagnetic thrust directly drives the unloaded weight 8 and the load 12 to reciprocate up and down, thereby achieving precise and highly responsive mechanical excitation, driving the entire counterweight to reciprocate up and down along the guide rail support column 11.

[0046] Since the leaf spring 2 is connected to the guide rail support column 11 and the unloaded weight 8 respectively, the vertical spring steel plate in the leaf spring 2 connected to the unloaded weight 8 allows and guides the counterweight to move in the vertical direction, providing elastic recovery and motion stability; the horizontal spring steel plate connected to the guide rail support column resists lateral displacement, restricts the counterweight from swaying left and right / back and forth, and ensures the directionality of motion; during the motion, it plays a vertical guiding and lateral restraining role on the leaf spring 2, suppresses small disturbances in non-vertical directions, and makes the counterweight always maintain a stable and symmetrical vertical excitation path, further improving the directional consistency and repeatability of the excitation signal, and ensuring the stable excitation quality of seismic waves.

[0047] At the same time, the static load of the counterweight is transferred to the air spring through the connector 3. The air spring undertakes its static support function and provides partial buffering and balance for the movement of the counterweight through its elastic restoring force, thus extending its service life.

[0048] During the excitation process, the acceleration and mass of the unloaded hammer 8 and the load 12 together generate an excitation reaction force, which is transmitted to the ground through the ground contact plate 7, forming a stable seismic wave signal. Since the ground contact plate 7 is connected to the entire device of this invention via the guide rail support column 11 and is tightly coupled to the ground, efficient energy transmission is ensured. This invention abandons the traditional method of using a pressing mass block, and instead uses high-density materials to increase the weight of the ground contact plate 7 to ensure effective ground coupling. This reduces the number of components that might distort the signal while minimizing the impact on the coupling between the ground contact plate 7 and the ground.

[0049] To prevent runaway or electromagnetic control failure in extreme situations, the limit block 9 is located above the ground contact plate 7. It can provide mechanical limit when the counterweight is abnormally displaced, avoid impacting the track 4, and ensure structural safety.

[0050] After the seismic exploration work is completed, the power is turned off, the drive coil 5 is de-energized, and the counterweight slowly returns to its lowest position under gravity. Optionally, the fasteners 6 are reinstalled to lock the unloaded counterweight 8, facilitating the equipment's relocation or transport.

[0051] In addition, to meet the weight and size requirements of the equipment during transportation, the load 12 can be disassembled according to the actual operation schedule. The load 12 is detachably connected to the unloaded counterweight 8 by bolts. Before the equipment is moved, 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 work site, the load 12 is reinstalled on the unloaded counterweight 8 according to the required excitation energy to adjust the excitation mass and ensure that the performance of the vibration source meets the geological conditions of the new site.

[0052] The structure described in this invention utilizes a linear motor to directly drive the counterweight to vibrate up and down, eliminating the need for a traditional hydraulic system. This invention features a more compact structure, faster response speed, and higher control precision. The counterweight mass can be adjusted via a detachable load 12 to adapt to vibration requirements under different geological conditions. Furthermore, this invention can achieve stable excitation in the 2Hz low-frequency range, exhibiting strong controllability and frequency adaptability. It is particularly suitable for the application of low-frequency seismic waves in oil and gas resource exploration and has broad application value.

[0053] Preferably, the vibrator includes two symmetrically mounted linear motors, with their tracks 4 and drive coils 5 distributed on both sides of the guide rail support column 11. Under control and coordination, the linear motors on both sides output equal driving forces in the same direction, forming a resultant force to achieve balanced excitation, improve signal quality, and reduce the risk of mechanical deviation.

[0054] Components not described in detail in this application are all existing conventional technologies and will not be described further here.

[0055] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A controllable vibration source device driven by a linear motor, characterized in that: The system includes a ground contact plate (7), a guide rail support column (11), an elastic element (10), a connector (3), a linear motor, and a counterweight. 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 opened below the top plate (113) of the guide rail support column (11). The middle connecting rod (33) of the connector (3) extends into the top plate (113) of the guide rail support column (11) to connect to the elastic element (10). The connector (3) is symmetrically connected at both ends to the counterweights placed on both sides of the guide rail support column (11). The linear motor has a track ( 4) Installed on both sides of the counterweight corresponding to the guide rail support column (11), a group of permanent magnets evenly arranged along the length direction is embedded in the track (4). 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). The generated excitation reaction force is transmitted to the ground contact plate (7) through the connector (3), elastic element (10) and guide rail support column (11), which drives the ground contact plate (7) to move up and down on the ground and generate seismic waves.

2. The linear motor-driven controllable vibration source device according to claim 1, characterized in that: The top plate of the guide rail support column (11) is connected to the hanger (101). The top plate (113) has a through hole into which the middle 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).

3. The linear motor-driven controllable vibration source device according to claim 2, characterized in that: 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 of the middle connecting rod (33).

4. The linear motor-driven controllable vibration source device according to claim 3, characterized in that: 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), ensuring that the connecting plate moves up and down in the groove (112) of the guide rail support column (11) along with the elastic element (10).

5. The linear motor-driven controllable vibration source device according to claim 2, characterized in that: The counterweight includes a detachably connected unloaded weight (8) and a load (12), and a linear motor drive coil (5) and a connector (3) are connected to the unloaded weight (8).

6. The linear motor-driven controllable vibration source device according to claim 5, characterized in that: Guide and limiting devices are respectively connected between the top of the unloaded hammer (8) and the hanger (101), and between the bottom of the unloaded hammer (8) and the guide rail support column (11).

7. The linear motor-driven controllable vibration source device according to claim 6, characterized in that: The guiding and limiting device is a leaf spring (2), which consists of horizontally arranged spring steel plates and vertically arranged spring steel plates fixed to each other at a 90° angle. The horizontally arranged spring steel plates are connected to the hanger (101) or the guide rail support column (11), and the vertically arranged spring steel plates are connected to the unloaded weight (8). The vertically arranged spring steel plates guide the unloaded weight (8) to move in the vertical direction, while the horizontally arranged spring steel plates restrict the unloaded weight (8) from moving in a non-vertical direction.

8. The linear motor-driven controllable vibration source device according to claim 5 or 6, characterized in that: During transportation, the ground contact plate (7) and the unloaded hammer (8) are connected by fasteners (6).

9. The linear motor-driven controllable vibration source device according to claim 1, characterized in that: The elastic element (10) is an air spring, and the upper and lower end faces of the air spring are planes.

10. The linear motor-driven controllable vibration source device according to claim 5, characterized in that: A limiting block (9) is also provided on the top surface of the ground contact plate (7) below the unloaded hammer (8), and the limiting block (9) is located 50-55mm below the limit position of the movement stroke of the unloaded hammer (8), thus limiting the impact of the unloaded hammer (8) on the ground contact plate (7).

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