A shallow well seismograph northward mounting device

Abstract

This utility model discloses a north-alignment installation device for a shallow well seismograph, belonging to the technical field of seismic observation equipment. The device includes a handle, a connecting rod, a downward-pressing shaft, and a downward-pressing plate. The downward-pressing plate is fixed to the outer shell of the shallow well seismograph and aligned with the north-pointing indicator of the seismograph. A cross-shaped locking hole is provided in the center of the downward-pressing plate. A T-shaped structure is provided on the downward-pressing shaft, which can be inserted into the cross-shaped locking hole and rotated to secure it. During operation, the downward-pressing plate is installed and fixed to the seismograph. After assembling the handle, connecting rod, and downward-pressing shaft, they are inserted into the cross-shaped locking hole of the downward-pressing plate and rotated to secure it. At this point, the handle is aligned with the north-pointing indicator of the seismograph, serving as a ground north-pointing indicator. The seismograph is then hoisted to the bottom of the well. After rotating the handle to align with geographic north, it is lowered. Pressing and rotating the handle in the opposite direction separates and retrieves the reusable components. This invention significantly reduces the cost of a built-in north-finding instrument in the seismograph, saving costs and shortening the installation time for north alignment of the shallow well seismograph. The overall operation is convenient and the north alignment is accurate.

Description

Technical Field

[0001] This utility model belongs to the technical field of earthquake observation equipment, specifically relating to a north-facing installation device for a shallow well seismometer. Background Technology

[0002] Seismometers are used to observe ground vibrations. There are many types of seismometers, including surface seismometers and shallow well seismometers. Surface seismometers are installed on the ground surface, while shallow well seismometers are installed in observation wells less than 50 meters below the surface, mostly 20 meters deep. These wells may contain water, and their inner diameter is generally 200–300 mm. Seismometer installation has azimuth requirements; the north marker on the seismometer must be aligned with geographic north to better record vibrations in all directions. Surface-mounted seismometers can be quickly installed according to their north-pointing indicator because the north marker is directly visible. Shallow well seismometers require cable hoisting to the bottom of the well. Due to the limitations of the well depth and diameter, personnel cannot enter the well for installation; therefore, the azimuth of the seismometer installed in the well is random.

[0003] There are generally two methods to make a shallow well seismograph point north. One method is to build a north-finding instrument inside the seismograph and use it to measure the azimuth of the downhole seismograph. However, built-in north-finding instruments are expensive, with low-precision instruments costing about 50,000 to 60,000 yuan and high-precision instruments costing as much as 100,000 to 150,000 yuan. If each shallow well seismograph is equipped with a north-finding instrument, the cost of the seismograph will increase significantly, thus affecting its competitiveness. The other method is to install a seismograph on the ground that is already pointing to geographical north as a standard seismograph. This standard seismograph is used to compare the azimuth of the downhole seismograph with that of the ground seismograph. The angle of deviation between the downhole seismograph and the standard ground seismograph is calculated by analyzing the noise records. This angle is then input into the acquisition unit for software subtraction. This method is called downhole azimuth correction. However, the method of correction by using the azimuth angle of the well requires continuous noise recording and comparison tests between the downhole seismograph and the surface standard seismograph. The comparison test needs to be carried out in a quiet environment and requires continuous observation for at least several hours. If there is interference from natural environment such as strong winds or heavy rain on the ground, or interference from human activities, this comparison test may even need to last for dozens of hours, which greatly increases the time and manpower costs. Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a shallow well seismograph north-alignment installation device that can quickly complete the installation and north-alignment of the shallow well seismograph, improve efficiency, and reduce the cost of the seismograph.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0006] A north-aligning mounting device for a shallow well seismograph includes a handle, a connecting rod, a downward-pressing shaft, and a downward-pressing plate. The handle, serving as a north-pointing indicator for the shallow well seismograph, is fixedly connected to the top of the connecting rod. The bottom of the connecting rod is fixedly connected to the connecting end of the downward-pressing shaft, the other end of which is a T-shaped end with a T-shaped structure. The downward-pressing plate is used to fix the device to the outer casing of the shallow well seismograph, and its orientation matches that of the north-pointing indicator. A cross-shaped locking hole is provided in the middle of the downward-pressing plate. The T-shaped end of the downward-pressing shaft is inserted into the cross-shaped locking hole and rotated 90 degrees to engage and fix the T-shaped structure with the cross-shaped locking hole. At this time, the orientation of the handle is consistent with that of the downward-pressing plate.

[0007] Before installing the shallow well seismograph, first fix the lower pressure plate to the seismograph casing (the lower pressure plate should be aligned with the north indicator of the shallow well seismograph). Then assemble the handle, connecting rod, and lower pressure shaft. Insert the T-shaped end of the lower pressure shaft into the cross-shaped locking hole of the lower pressure plate and rotate it 90 degrees to lock it in place. At this point, the handle should be aligned with the north indicator of the shallow well seismograph (if the handle points north on the ground, the seismograph in the well will also point north). Then hoist the seismograph with the north alignment device to the bottom of the well. Use the handle to control the connecting rod to lift the seismograph about 10 cm and rotate it until the handle points to geographic north. Then lower the seismograph to complete the north alignment. After completing the north alignment, press down and rotate the handle 90 degrees in the opposite direction. The T-shaped structure on the lower pressure shaft can then disengage from the cross-shaped locking hole of the lower pressure plate, separating the connecting rod from the lower pressure plate. The handle, connecting rod, and lower pressure shaft can be reused, while one lower pressure plate is installed on each seismograph. The elimination of the need for an expensive north-finding instrument within the seismometer significantly reduces costs, saving tens of thousands or even hundreds of thousands of yuan per shallow well seismometer. Furthermore, the north-finding operation eliminates the need for long waits for a quiet environment, reducing the hours or even tens of hours required for installing the shallow well seismometer for north-finding to within 10 minutes. The operation is convenient, and the core components can be reused, further saving on operating costs.

[0008] As a further description of the above technical solution, a connecting ring is also included, through which the connecting rods can be spliced ​​and extended. The length of each connecting rod can be designed to vary depending on the well depth, but for ease of transportation, the length of each connecting rod is generally set to 2-3 meters. In use, multiple connecting rods can be spliced ​​and extended according to different well depths through the connecting ring, which can flexibly adapt to shallow wells of different depths. There is no need to customize connecting rods of specific lengths for different well depths, significantly improving the versatility and flexibility of the device.

[0009] As a further description of the above technical solution, a telescopic spring is sleeved on the lower pressure shaft, located between the connecting end and the T-shaped end. When separating the components after northward alignment, the operator can press down on the handle, and the elastic deformation of the telescopic spring will provide a restoring force, allowing the T-shaped end of the lower pressure shaft to smoothly disengage from the cross-shaped locking hole of the lower pressure plate, avoiding jamming and significantly improving operational convenience. Simultaneously, the buffering effect of the telescopic spring reduces collision wear between components during separation, protecting reusable components such as the handle, connecting rod, and lower pressure shaft, extending their service life, and further reducing operating costs. Combined with the device's original low-cost and high-efficiency advantages, it better meets the actual needs of northward alignment operations for shallow well seismometers.

[0010] As a further description of the above technical solution, the cross-shaped locking hole includes a first oblong hole and a second oblong hole. The first oblong hole and the second oblong hole are perpendicular to each other. The first oblong hole is a through hole, and the second oblong hole is a countersunk hole located on the bottom surface of the lower pressure plate. During installation, the T-shaped end of the lower pressure shaft is inserted into the first oblong hole until the T-shaped structure passes through the cross-shaped locking hole and is exposed. The handle is rotated 90 degrees so that the T-shaped structure is aligned with the second oblong hole. The handle is then pulled upwards, and the T-shaped structure is locked in the second oblong hole, thereby locking and fixing the lower pressure shaft to the lower pressure plate. During disassembly, the handle is pressed down to disengage the T-shaped structure from the second oblong hole. The handle is then rotated 90 degrees in the opposite direction so that the T-shaped structure is aligned with the first oblong hole. The handle is then pulled upwards to separate the lower pressure shaft from the lower pressure plate, completing the retrieval of the lower pressure shaft, connecting rod, and handle.

[0011] As a further description of the above technical solution, the handle and connecting rod, the connecting rod and connecting ring, and the connecting rod and lower pressure shaft are all fixed with pins. The pin-fixed connection has high strength and good stability, preventing loosening or relative displacement between components during underground hoisting, rotation for north alignment, and pulling operations. This ensures that when the handle rotates, it can synchronously drive the connecting rod, lower pressure shaft, and lower pressure plate (i.e., seismometer) to accurately adjust the azimuth, guaranteeing north alignment accuracy.

[0012] As a further description of the above technical solution, the lower pressure plate has mounting holes at both ends for mounting it onto the housing of the shallow well seismometer. This provides a clear and stable connection point for fixing the lower pressure plate to the housing of the shallow well seismometer. The lower pressure plate can be firmly installed on the seismometer housing using conventional fasteners such as bolts, preventing the lower pressure plate from shifting or loosening during the device's hoisting, northward rotation, and pulling processes in the well, and ensuring that the azimuth consistency between the lower pressure plate and the seismometer's north indicator is not compromised.

[0013] Compared with the prior art, the beneficial effects of this utility model are:

[0014] This invention relates to a shallow well seismograph north-alignment device. Through a mechanical linkage structure consisting of a handle, connecting rod, lowering shaft, and lowering plate, it eliminates the need for an expensive built-in north-finding instrument, significantly reducing costs and saving tens of thousands to hundreds of thousands of yuan per unit. Furthermore, the handle, connecting rod, and lowering shaft are reusable, requiring only the lowering plate per unit, drastically reducing equipment cost and operating expenses. Unlike standard ground seismograph comparisons, it eliminates the need for continuous noise recording and analysis in a quiet environment for hours or even tens of hours. Accurate north alignment is achieved simply by lifting and rotating the handle (within 10 minutes), significantly improving operational efficiency. Additionally, the connecting rod can be adapted to different well depths via connecting rings, and the components are secured by pins and T-shaped structures with cross-shaped locking holes, ensuring a stable connection and accurate north alignment. The overall operation is convenient and the structure reliable, effectively solving the core shortcomings of existing technologies, such as high cost and low efficiency. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of the shallow well seismograph northward-facing device of this utility model.

[0016] Figure 2 This is a perspective view of the handle in this utility model.

[0017] Figure 3 This is a perspective view of the connecting rod in this utility model.

[0018] Figure 4 This is a perspective view of the connecting ring in this utility model.

[0019] Figure 5 This is a perspective view of the downward pressing shaft in this utility model.

[0020] Figure 6 This is a perspective view of the lower pressure plate in this utility model.

[0021] Figure 7 yes Figure 6 The main view.

[0022] Figure 8 yes Figure 7 AA sectional view.

[0023] Figure label:

[0024] 10-Handle; 20-Connecting rod; 30-Connecting ring; 40-Pressing shaft; 41-T-shaped structure; 50-Pressing plate; 51-Cross-shaped hole; 51a-First oblong hole; 51b-Second oblong hole; 52-Mounting hole; 60-Telescopic spring. Detailed Implementation

[0025] The technical solution of this utility model will be clearly and completely described below with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0026] Please see Figures 1-8 A north-aligning installation device for a shallow well seismograph comprises a handle 10, a connecting rod 20, a connecting ring 30, a downward-pressing shaft 40, and a downward-pressing plate 50, all components being made of 304 stainless steel. The handle 10 is used to operate and rotate the connecting rod 20 to align the downhole seismograph northward. The connecting rod 20 connects the handle 10 and the downward-pressing shaft 40. The connecting rod 20 can be extended by splicing with the connecting ring 30. The length of each connecting rod 20 can be designed differently according to the well depth, but for ease of transportation, the length of each connecting rod 20 is set to 2-3 meters. Multiple connecting rods 20 can be used to extend the well depth by splicing with the connecting ring 30. The downward-pressing shaft 40 is installed on the last connecting rod 20. One end of the downward-pressing shaft 40 is a connecting end for connecting to the connecting rod 20, and the other end is a T-shaped end with a T-shaped structure 41. The T-shaped structure 41 is mainly used to lock the downward-pressing plate 50. A telescopic spring 60 is fitted onto the downward-pressing shaft 40. The handle 10 is fixed to the connecting rod 20, the connecting rod 20 to the connecting ring 30, and the connecting rod 20 at the end to the pressure shaft 40 by pins. The pressure plate 50 is installed on the top of the seismometer housing through the mounting holes 52 at both ends. The pressure plate 50 and the north direction of the seismometer are aligned. The pressure plate 50 has a cross-shaped locking hole 51 in the middle, which includes a first oblong hole 51a and a second oblong hole 51b. The first oblong hole 51a and the second oblong hole 51b are perpendicular to each other. The first oblong hole 51a is a through hole, and the second oblong hole 51b is a countersunk hole located on the bottom surface of the pressure plate 50. After the downward rotating shaft 40 is inserted into the first oblong hole 51a of the cross-shaped locking hole 51 of the downward pressure plate 50, it is rotated 90 degrees clockwise (or counterclockwise depending on the insertion direction) by the handle 10. The handle 10 is then pulled up slightly to make the T-shaped structure 41 lock into the second oblong hole 51b, thereby fixing the downward rotating shaft 40 to the downward pressure plate 50. At this time, the handle 10 and the downward pressure plate 50 are aligned. The handle 10 can be used as a north-pointing indicator for the seismograph. As long as the handle 10 points north on the ground, the seismograph in the well will also point north.

[0027] After the north-pointing device and the seismograph are assembled, the seismograph is lowered into the well. Then, by controlling the connecting rod 20 through the handle 10, the seismograph in the well is lifted slightly by 10 centimeters and rotated until the handle 10 points to geographic north. Then the seismograph can be lowered to complete the north-pointing work of the seismograph in the well.

[0028] After completing the northward alignment, the connecting rod 20 and the downward-pressing shaft 40 need to be retrieved. At this point, the downward-pressing shaft 40 at the end of the connecting rod 20 plays a crucial role. The downward-pressing shaft 40 is fitted with a telescopic spring 60. After the ground operator presses down forcefully and rotates the handle 10 90 degrees in the opposite direction, the T-shaped structure 41 on the downward-pressing shaft 40 can detach from the second oblong hole 51b. Then, by pulling the handle 10 upwards, the T-shaped structure 41 slowly separates from the downward-pressing plate 50 along the first oblong hole 51a, completing the separation of the connecting rod 20 and the downward-pressing plate 50. The handle 10, connecting rod 20, and downward-pressing shaft 40 can be reused, while the downward-pressing plate 50 remains on the seismometer. The seismometer can be retrieved to the ground via the data cable.

[0029] The north-finding device for shallow well seismographs of this invention can greatly save the cost of the built-in north-finding instrument in the seismograph, saving tens of thousands or even hundreds of thousands of yuan per shallow well seismograph. It also reduces the work required for installing the shallow well seismograph and pointing north from several hours or even tens of hours to be completed within 10 minutes.

[0030] The above description is merely the preferred embodiment of this utility model. It should be noted that, for those skilled in the art, various modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from its principles, and these modifications or substitutions can also achieve the technical effects of this utility model, and should also be considered within the protection scope of this utility model.

Claims

1. A shallow well seismometer north-up mounting device, characterized by: The device includes a handle (10), a connecting rod (20), a pressure shaft (40), and a pressure plate (50). The handle (10) serves as a north-pointing indicator for the shallow well seismometer and is fixedly connected to the top of the connecting rod (20). The bottom of the connecting rod (20) is fixedly connected to the connecting end of the pressure shaft (40). The other end of the pressure shaft (40) is a T-shaped end with a T-shaped structure (41). The pressure plate (50) is used to be fixedly installed on the outer shell of the shallow well seismometer, and the orientation of the pressure plate (50) is consistent with the orientation of the north-pointing indicator of the shallow well seismometer. A cross-shaped locking hole (51) is provided in the middle of the pressure plate (50). The T-shaped end of the pressure shaft (40) is inserted into the cross-shaped locking hole (51) and rotated 90 degrees so that the T-shaped structure (41) engages and is fixed with the cross-shaped locking hole (51). At this time, the orientation of the handle (10) is consistent with the orientation of the pressure plate (50).

2. The shallow well seismometer north-up mounting device of claim 1, wherein: It also includes a connecting ring (30), through which the connecting rod (20) can be spliced ​​and extended.

3. A shallow well seismometer north-up mounting arrangement according to claim 1 or 2, characterised in that: A telescopic spring (60) is sleeved on the downward pressing shaft (40), and the telescopic spring (60) is located between the connecting end and the T-shaped end.

4. The shallow well seismometer north-facing installation device according to claim 3, characterized in that: The cross-shaped hole (51) includes a first oblong hole (51a) and a second oblong hole (51b). The first oblong hole (51a) and the second oblong hole (51b) are perpendicular to each other. The first oblong hole (51a) is a through hole, and the second oblong hole (51b) is a countersunk hole located on the bottom surface of the lower pressure plate (50).

5. The shallow well seismometer north-facing installation device according to claim 2, characterized in that: The handle (10) and the connecting rod (20), the connecting rod (20) and the connecting ring (30), and the connecting rod (20) and the pressing shaft (40) are all fixed with pins.

6. The shallow well seismometer north-facing installation device according to claim 1, characterized in that: The lower pressure plate (50) has mounting holes (52) at both ends for mounting it onto the housing of the shallow well seismometer.

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