Underground water level engineering exploration method and system based on well point measurement method

Abstract

The present invention discloses a method and system for underground water level engineering investigation based on the well point measurement method, belonging to the technical field of engineering investigation. The method is implemented based on the system, and the method is as follows: The measurement of the underground water level in the logging well is realized based on a rope, a measurement module and an underwater component. The underwater component includes a rod barrel, a floating body and a detection module; In this method, the underwater component is installed in the logging well; In this method, the method for obtaining the underground water level is as follows: The measurement module obtains the position of the rod barrel in the logging well by measuring the length of the rope released in the logging well; The detection module obtains the position of the floating body on the rod barrel; According to the position of the rod barrel in the logging well and the position of the floating body on the rod barrel, the position of the floating body relative to the wellhead of the logging well is obtained and this position is used as the position of the underground water level in the logging well; By lifting or releasing the rod barrel through the rope, the state of the rod hole and the floating body relative to the liquid level of the logging well is maintained. This solution has the characteristics of low implementation cost and can ensure the accuracy of water level measurement.

Description

Technical Field

[0001] The present invention relates to the technical field of engineering investigation, and particularly to an underground water level engineering investigation method and system based on a well point measurement method. Background Art

[0002] In engineering investigation, the well point measurement method is a method for measuring the underground water level by using a logging well with relatively low implementation cost. The commonly used methods include the sounding line method, the static pressure method, and the float method. Among them, the sounding line method uses a sounding line or a steel tape, and a sensor is connected to the lower end of the sounding line or the steel tape. When the sensor is lowered and contacts the water surface, the underground water level in the logging well is obtained by using the amount of the sounding line or the steel tape released when the sensor responds. The static pressure method uses a pressure sensor, and the static pressure detection result of the pressure sensor is converted into the water level depth in the logging well, so as to obtain the underground water level in the logging well. The float method uses a float floating in the logging well. The float rises or falls with the change of the water level, and the position of the float in the logging well is obtained by using the movement of the rope that changes with the position of the float, so as to obtain the underground water level in the logging well. Compared with the sounding line method, the static pressure method and the float method are methods that can continuously measure the underground water level.

[0003] In engineering construction, taking the control of the foundation pit water as an example, an important means is to set a number of dewatering wells, recharge wells, and recharge ditches on the side of the foundation pit. By controlling the underground water level, the smooth progress of the construction and the safety of the existing buildings around the foundation pit are ensured. During the implementation of water control, continuous water level measurements need to be carried out on multiple logging wells to obtain the regional underground water level surface and the water level change trend. At the same time, in addition to the influence of the aquifer, compared with the underground water level without human intervention, due to the existence of artificial pumping and water replenishment, the underground water level in the logging well has the characteristic of large fluctuations within a certain range. The principle of the sounding line method is to actively release the sounding line and obtain the underground water level by obtaining the released amount of the sounding line length. Therefore, it is not suitable for the continuous measurement of the water level in this kind of logging well. When measuring the underground water level by the float method, the float pulls the rope to move, and the movement amount of the rope is recorded by the drum. The transmission resistance is large. When the water level changes significantly, there are problems of result lag and poor accuracy. The implementation cost of the static pressure method is relatively high, and at the same time, the accuracy is greatly affected by environmental factors such as air pressure and temperature. The water quality conditions also have a great impact on the measurement accuracy and maintenance cost.

[0004] In the prior art, usually one of the sounding line method, the static pressure method, and the float method or ultrasonic measurement method, radar measurement method, etc. is used to complete the water level measurement in the logging well. From the perspective of controlling the cost and accuracy of the logging well water level measurement, it is necessary to further optimize the related methods and systems. Summary of the Invention

[0005] In view of the problem of measuring the groundwater level in well logging, the present invention provides a groundwater level engineering survey method and system based on the well point measurement method. This method and system have the characteristics of low implementation cost and can ensure the accuracy of water level measurement.

[0006] The present invention relates to a groundwater level engineering survey method based on the well point measurement method. This method realizes the measurement of the groundwater level in a well logging based on a rope, a measurement module, and an underwater component. Among them, the underwater component is connected to the lower end of the rope, and the measurement module is used to measure the length of the rope released in the well logging. The underwater component includes a rod barrel, a floating body, and a detection module. The upper end of the rod barrel is connected to the lower end of the rope, the floating body is arranged in the rod hole of the rod barrel, and the rod hole is communicated with the outside of the rod barrel through a communication hole;

[0007] In this method, the underwater component is installed in the well logging. Specifically, the rod barrel is suspended in the well logging by a rope and kept plumb. The detection module is installed on the rod barrel, and the rod hole has a state where the lower end is below the liquid level of the well logging, the upper end is above the liquid level of the well logging, and the floating body floats on the liquid surface of the well logging;

[0008] In this method, the method for obtaining the groundwater level is as follows: The measurement module obtains the position of the rod barrel in the well logging by measuring the length of the rope released in the well logging; the detection module obtains the position of the floating body on the rod barrel; according to the position of the rod barrel in the well logging and the position of the floating body on the rod barrel, the position of the floating body relative to the well head of the well logging is obtained and this position is used as the position of the groundwater level in the well logging;

[0009] During the groundwater level measurement process, the rod barrel is lifted or released through the rope to keep the state of the rod hole and the floating body relative to the liquid level of the well logging.

[0010] In the application where precipitation wells, recharge wells / recharge ditches are arranged around the well logging (measurement well for groundwater level measurement), it is necessary to make the groundwater level lines in the areas between the precipitation wells and the recharge ditches and between the precipitation wells and the recharge wells inclined. During the process of adjusting the influence of the precipitation wells, recharge wells / recharge ditches on the groundwater level, the liquid level in the well logging is affected by the precipitation wells, recharge wells / recharge ditches, and there are obvious groundwater level changes in the well logging during the measurement period. When using the relatively low-cost and relatively high-precision sounding rope method to measure the liquid level position of this type of well logging, it is not convenient to complete continuous monitoring of the liquid level position. When using the relatively low-cost float method to continuously measure the liquid level of the well logging, the frequent fluctuations of the liquid level will cause the measurement accuracy to be too poor. Based on the above, a technical solution that combines the sounding rope method and the float method to complete the groundwater level engineering survey is provided, aiming to provide a groundwater level measurement solution with the characteristics of low implementation cost and can ensure the accuracy of water level measurement.

[0011] The principle of this solution for measuring the groundwater level is as follows: When the underwater component is suspended in the logging well in a state where the rod tube is used as a plumb bob based on the rope, at this time, the measurement module can obtain the current position of the rod tube in the logging well based on the length of the rope released in the logging well; since the rod tube has a certain length, and in the current rod hole, the lower end is below the liquid level of the logging well, the upper end is above the liquid level of the logging well, and the floating body floats on the liquid surface of the logging well. Therefore, when the liquid level of the logging well fluctuates with the change of the groundwater level line, with the position of the rod tube in the logging well remaining unchanged, due to the fact that the floating body can float up and down to a certain extent along the rod hole with the liquid level of the logging well. After the position of the floating body on the rod tube is obtained through the detection module, the position of the floating body in the logging well can be obtained by combining the above two positions, and this position is used as the position of the liquid surface of the logging well. When the liquid level in the logging well changes to a state where the floating body cannot move further down or up along the rod hole in the rod tube, or the floating body does not float on the liquid surface of the logging well, by lifting or releasing the rod tube through the rope, the state can be restored to a state where the floating body can continuously measure the position of the liquid surface of the logging well within a certain stroke range.

[0012] Different from the float method and the sounding line method used in the prior art, in this solution, after the underwater component is released to an appropriate position (in the said state), the movement of the floating body within a certain range and the position of the floating body are detected by the detection module installed on the rod tube, and finally the position of the liquid surface of the logging well is obtained. Therefore, compared with the prior art sounding line method for measuring the liquid level of the logging well, there is no need to lift or release the rope to obtain a single liquid level value, that is, after the underwater component is placed in position once, it can continuously measure the liquid level of the logging well within a certain range; in the structural design and functional design of the underwater component, the detection module obtaining the position of the floating body on the rod tube is not affected by the rope, etc., that is, the problems of result lag and poor accuracy caused by the transmission resistance due to the need for the float to pull the rope during the measurement of the groundwater level by the float method are eliminated; when the draft depth of the rod tube in the logging well changes and causes the said state to change, the position of the underwater component in the logging well can be adjusted by the rope. Therefore, this solution is applicable to the measurement of the groundwater level in the case of a large change in the position of the liquid surface in the logging well.

[0013] In a specific implementation, to enable the smooth release and lifting of the underwater component and reduce the interference caused by factors such as wellbore collapse to the movement of the floating body with the liquid level, before the underwater component is installed in the logging well, a casing serving as a logging well protection tube is installed in the logging well. The side wall of the casing has a pipe hole, and the pipe hole serves as a communication hole between the liquid level inside the casing and the peripheral geological liquid level line. After the installation of the casing is completed, the water body in the logging well is left to stand. When the water body is clear, the underwater component is then installed in the logging well to avoid the interference of sediment settlement on the smooth rise and fall of the floating body.

[0014] In a specific embodiment, the method for maintaining the state of the holding rod hole and the floating body relative to the logging liquid level is as follows: Determine the draft depth of the rod barrel in the logging. When the draft depth is less than or equal to the lower threshold, the rope releases the rod barrel and makes the draft depth of the rod barrel reach the set depth; when the draft depth is greater than or equal to the upper threshold, the rope lifts the rod barrel and makes the draft depth of the rod barrel reach the set depth;

[0015] The method for determining the draft depth is any one of the following methods:

[0016] It is realized according to the position of the floating body on the rod barrel obtained by the detection module;

[0017] It is realized according to the liquid level switches installed at the upper end and the lower end of the rod barrel.

[0018] It is easy to understand that the rod barrel adopts a structure that will sink into the logging without the pulling of the rope. After the rod barrel is held at a specific position in the logging under the pulling of the rope, as the liquid level in the logging changes, the floating body will rise or fall along the rod hole with the liquid level. When the liquid level drops too much, the floating body will drop to the bottom of the rod barrel and be restricted by the rod barrel and cannot further drop with the liquid level. When the liquid level rises too much, the floating body will rise to the top of the rod barrel and be restricted by the rod barrel and cannot further rise with the liquid level. The change of the above liquid level position is accompanied by the change of the draft depth of the rod barrel in the logging. The above solution provides a specific method for monitoring the change of the state. Specifically, match the lower threshold, the set depth, and the upper threshold associated with the draft depth. The lower threshold and the upper threshold are used as the trigger values for triggering the rope to release the rod barrel and lift the rod barrel. When the draft depth reaches the corresponding threshold and triggers the rope to act, the rod barrel is lowered or lifted to the set depth where the floating body can rise and fall to adapt to the rise and fall of the liquid level for groundwater measurement.

[0019] In a specific embodiment, since the position of the floating body in the rod barrel changes with the change of the draft depth, the detection value of the detection module can be used as the basis for determining the draft depth, or a separate liquid level switch can be configured for the rod barrel. For example, by setting the liquid level switches at the upper end and the lower end of the rod barrel respectively, the determination of whether the upper threshold is reached and the determination of whether the lower threshold is reached can be realized.

[0020] In a specific embodiment, the method for the measurement module to obtain the position of the rod barrel in the logging is as follows: By obtaining the number of rolling circles of the roller in contact with the rope on the measurement module, the length of the rope released in the logging is obtained. Among them, the roller is configured as follows: It is set at the wellhead position of the logging, and the wheel surface of the roller is in contact with the side surface of the rope. When the rope is lifted and released, the roller rotates under the friction of the rope and is synchronized with the movement speed of the rope;

[0021] The method for the detection module to obtain the position of the floating body on the rod barrel is any one or several of the following methods:

[0022] A permanent magnet is provided in the floating body. When the permanent magnet moves along the rod hole relative to the rod barrel with the floating body, the detection module obtains the position of the floating body on the rod barrel by sensing the magnetic field of the permanent magnet;

[0023] The bottom of the floating body is connected to a tension sensor arranged at the bottom of the rod barrel through an elastic cord or a constant force spring. The tension sensor is used to measure the tension exerted on it by the floating body. The detection module converts the tension into the elongation of the elastic cord or the constant force spring, and calculates the position of the floating body on the rod barrel according to the elongation.

[0024] The above scheme provides a specific method for the measurement module to obtain the position of the rod barrel in well logging. The principle is as follows: When the rope is lifted or lowered, the friction between the rope and the roller forces the roller to move with the rope. According to the rotation direction of the roller, it can be determined whether the rope is being lowered or lifted. According to the number of turns and the angle of rotation of the roller, the lifting amount or lowering amount of the rope can be determined. In this measurement method, the measurement of the position of the rod barrel is not affected by the winding radius of the rope on the following drum module, nor by the shape of the rope turns on the drum module. On the premise of a simple scheme, the position of the rod barrel in well logging can be correctly obtained. A better application is to clamp the rope by two rollers. Each roller is a metal wheel with a ring groove on its wheel surface, and a rubber layer is provided on the groove surface of the ring groove, and an abrasion-resistant cloth surface layer is provided on the surface of the rubber layer. The rubber layer undergoes elastic deformation under the extrusion of the rope. By adopting this scheme, a reliable supporting force can be maintained between the rope and the wheel surface so that the roller can move synchronously with the rope. The abrasion-resistant cloth surface layer is used to adapt to the rope made of steel wire rope and keep the performance of the measurement module reliable for a long time.

[0025] The above solution provides a specific method for the detection module to obtain the position of the floating body on the rod tube. The principle is as follows: for a floating body provided with a permanent magnet, when the floating body moves with the liquid level position, the permanent magnet moves in the rod tube along with the floating body. In this way, the detection module obtains the position of the floating body through magnetic induction. The detection module can adopt structures such as magnetic induction coils and waveguide wires; for a floating body connected to the bottom of the rod tube through an elastic rope or a constant force spring, as the floating body moves, the elongation of the elastic rope or the constant force spring changes. At this time, the force exerted by the elastic rope or the constant force spring on the tension sensor changes. Therefore, based on the measurement result of the tension sensor, it can be converted into the position of the floating body on the rod tube. Compared with magnetic induction coils and waveguide wires, this structure not only has the characteristics of low cost, but also has a simple supporting structure, is not easily affected by electromagnetic fields in the environment in terms of measurement accuracy, has low power consumption, and is convenient for power supply. Preferably, since the draft depth of the floating body will change after the elongation of the elastic rope or the constant force spring changes, when determining the logging liquid level position based on the position of the floating body on the rod tube, the measurement result of the tension sensor is used to correct the logging liquid level position. Preferably, the floating body is set to have an equal-diameter cylindrical structure in the draft section. Since there is a matching relationship between the tension and the buoyancy, it can be set to obtain the correction coefficient K through experiments. This K value is used to eliminate the influence of the floating body under different tensions and draft depths on the measurement result of the groundwater level.

[0026] In a specific embodiment, the lifting or releasing of the rod tube by the rope is realized under the action of the drum module. The upper end of the rope is wound around the drum module. After the position of the rod tube in the logging is fixed, the measured value of the measurement module is read and stored. When the position of the rod tube changes, the measured value of the measurement module is read and stored again.

[0027] The detection module obtains the position of the floating body on the rod tube according to the set measurement frequency. After each completion of the position detection of the floating body on the rod tube by the detection module, the position detection result of the floating body on the rod tube is transmitted to the processing module. The processing module obtains the position of the groundwater level in the logging based on the currently stored measured value and the current detection result, and uses the detection result as the determination basis for the operation of the drum module. The operation of the drum module is used to maintain the state of the rod hole and the floating body relative to the logging liquid level.

[0028] The above solution provides a technical solution in which the position of the rod barrel in well logging depends on the drum module. It provides a technical solution for recording the measured value of the measurement module after the drum module completes a single action, so that when calculating the groundwater level in well logging, the position of the rod barrel can be efficiently read. It provides a technical solution for using the position detection result of the detection module as the basis for groundwater level measurement and drum module operation determination in well logging. Specifically, the storage location of the measured value can be stored on the rope processing module. After the detection module completes a floating body position detection, it immediately uploads the detection result to the processing module for groundwater level calculation, completes a groundwater level measurement, completes a determination of the draft depth of the rod barrel, and determines whether to adjust the position of the rod barrel relative to the liquid level in the well logging through the drum module.

[0029] This solution also relates to a groundwater level engineering exploration system based on the well point measurement method, which is used to implement the groundwater level engineering exploration method described in any one of the above. It is easy to understand that this groundwater level engineering exploration system is a groundwater level engineering exploration system for implementing the above groundwater level engineering exploration method.

[0030] In a specific embodiment, the groundwater level engineering exploration system includes a rope, a measurement module, and an underwater component. The underwater component is connected to the lower end of the rope. The measurement module is used to measure the length of the rope released in the well logging. The underwater component includes a rod barrel, a floating body, and a detection module. The upper end of the rod barrel is connected to the lower end of the rope. The floating body is arranged in the rod hole of the rod barrel. The rod hole is communicated with the outside of the rod barrel through a communication hole. The detection module is installed on the rod barrel and is used to obtain the position of the floating body on the rod barrel.

[0031] The rod barrel is a mesh tube, and it also includes a filter screen wrapped outside the rod barrel. The mesh holes on the mesh tube serve as the communication holes, and the filter screen covers each communication hole.

[0032] Both the upper end and the lower end of the floating body are in the shape of elliptical head structures protruding relative to the ends.

[0033] This solution is different from the above solutions. A technical solution is provided that uses a perforated pipe as the rod barrel. The perforated pipe not only enables good water body communication between the rod hole and the logging, but also provides a rod barrel implementation solution with strong structural stability. The filter screen is used to prevent impurities in the logging from entering the rod hole, avoiding, for example, the deposition of impurities around the floating body, the sinking or floating objects entrained in the communication holes, which may affect the sensitivity of the floating body rising or falling relative to the rod barrel. The end shape of the floating body is used to achieve: in order to reduce the influence of the floating body shaking in the rod barrel on the detection of the floating body position, when the floating body has a small clearance fit with the rod hole, by avoiding the end of the floating body being blocked when the floating body moves relative to the rod barrel, the end shape can effectively ensure the sensitivity of the floating body rising or falling relative to the rod barrel. From the perspective of the floating body movement sensitivity, an arc chamfer can be set at the end position of the floating body to replace the elliptical head-shaped structure. However, when the top surface of the floating body is a plane, the influence of water droplets falling on this plane on the position of the floating body will be much greater than the influence of water droplets falling on the elliptical head-shaped structure on the position of the floating body.

[0034] In a specific embodiment, a first partition and a second partition located below the first partition are provided at the bottom of the rod barrel. The first partition and the second partition form a water isolation chamber inside the rod barrel. The detection module includes a tension sensor. The lower end of the tension sensor is fixedly connected to the second partition, and the upper end of the tension sensor is fixedly connected to a pull rod. The pull rod passes through the first partition through a through hole on the first partition, and an O-ring seal is provided between the hole wall of the through hole and the pull rod.

[0035] The lower end of the floating body is connected to the upper end of the pull rod by an elastic rope or a constant force spring.

[0036] The above solutions provide a technical solution to enclose the electronic devices of the detection module in a water isolation chamber to facilitate the selection of corresponding electronic devices and ensure their performance reliability. Specifically, the pull rod is used as a rigid rod and as an intermediate connecting member for transmitting force between the tension sensor and the elastic rope or the constant force spring. Compared with, for example, an elastic rope or a constant force spring passing through a through hole, since the pull rod does not deform when being pulled, from the perspective of the gap between the sealed hole wall and the pull rod, this solution is easier to obtain reliable sealing performance and smaller movement resistance of the pull rod. The O-ring seal is used as the sealing structure at the position of the through hole. When the tension sensor is deformed by tension, compared with, for example, a packing seal structure, this sealing structure can reduce the movement resistance of the pull rod to improve the measurement accuracy of the tension sensor. A better solution is to have multiple O-ring seals along the axis of the through hole, and use the upper O-ring seal to block sand grains and the like from entering the mating surface of the lower O-ring seal and the pull rod, thereby ensuring the sealing reliability of the water isolation chamber.

[0037] In a specific embodiment, the rod barrel includes a first barrel body, a second barrel body, and an end cap that are sequentially connected from top to bottom. The first barrel body and the second barrel body form a threaded connection relationship through connecting threads, and the second barrel body and the end cap form a threaded connection relationship through connecting threads;

[0038] The first partition is fixed at the lower end of the first barrel body, and the second partition is fixed at the lower end of the second barrel body. Central holes are provided on both the first partition and the second partition. The central hole on the first partition serves as the through hole. The tension sensor and the second partition are fixedly connected through a tension bolt. The central hole on the second partition serves as the bolt hole of the tension bolt;

[0039] An installation cavity for installing a signal transmission module and a storage battery is formed between the second partition and the end cap.

[0040] This solution provides a technical solution for convenient assembly of an underwater component. Specifically, after embedding a floating body with an elastic rope or a constant force spring connected to the lower end into the rod hole from the upper end of the first barrel body, the lower end of the elastic rope or the constant force spring passes through the first partition through the through hole. After completing the connection between the elastic rope or the constant force spring and the pull rod at the lower end of the first barrel body, install the tension sensor from the lower end of the first barrel body, and make the pull rod pass through the first partition through the through hole. At this time, the tension sensor is in a centered state in the first barrel body. Then, connect the second barrel body to the lower end of the first barrel body. After completing the docking of the second barrel body, the bolt hole at the lower end of the tension sensor is aligned with the central hole on the second partition. At this time, install the tension bolt from the bottom side of the second partition to complete the fixation of the bottom of the tension sensor on the second partition. Then, place electronic devices such as the signal transmission module and the storage battery into the enclosed space between the end cap and the second partition, and further close the enclosed space by rotating the end cap. During specific implementation, thread sealant is coated on the connection surface between the first barrel body and the second barrel body and on the connection surface between the second barrel body and the end cap. The thread sealant is used to achieve water isolation and anti-loosening.

[0041] In a specific embodiment, it further includes a drum module. The upper end of the rope is wound around the drum module, and it further includes a driving device for driving the drum module to rotate;

[0042] It further includes a signal transmission module. The signal transmission module receives the floating body position detection result of the detection module and transmits the position detection result to the control module of the driving device. The control module is used to: control the operation of the drum module and maintain the state of the rod hole and the floating body relative to the logging liquid level.

[0043] In the above solution, the driving device and the drum module enable the length adjustment of the rope released in the well logging to be completed through automatic control, so that the system has the characteristic of unattended operation during the underground water level monitoring process. The signal transmission module is used to establish an automatic control strategy for the floating body position and the rod barrel position.

[0044] In a specific embodiment, it further includes a support structure and a limit wheel. The drum module, the limit wheel, and the measurement module are all installed on the support structure, and the rope between the drum module and the measurement module is supported on the limit wheel;

[0045] The rope is a steel wire rope;

[0046] A biofilm inhibition coating is provided on the inner wall of the rod barrel and / or the outer wall of the floating body.

[0047] In the above solution, the limit wheel serves as a rope reversing wheel, so that when the rope is wound around different axial positions of the drum module or released from different axial positions of the drum module, the ropes on both sides of the measurement module have a stable angle. Preferably, under the action of the limit wheel, the ropes on both sides of the measurement module are in a straight state; the steel wire rope enables the rope to have a relatively small elongation under the tension of the underwater component, thereby ensuring the acquisition and detection accuracy of the measurement module for the rod barrel. The biofilm inhibition coating is used to inhibit the biofilm that may form on the inner wall of the rod barrel and / or the outer wall of the floating body, thereby ensuring the reliability and sensitivity of the floating body to rise and fall with the logging liquid level.

[0048] The present invention has the following beneficial effects:

[0049] In this solution, after the underwater component is released to an appropriate position, the movement of the floating body within a certain range and the position of the floating body are detected by the detection module installed on the rod barrel, and finally the position of the logging liquid level is obtained. Therefore, compared with the existing logging rope method for measuring the logging liquid level, it is not necessary to lift or release the rope for obtaining a single liquid level value, that is, the underwater component can continuously measure the logging liquid level within a certain range after being placed in place once.

[0050] In the structural design and functional design of the underwater component, the detection module obtaining the position of the floating body on the rod barrel is not affected by ropes, etc., that is, it eliminates the problems of result lag and poor accuracy caused by the transmission resistance during the process of measuring the groundwater level by the float method because the float needs to pull the rope to move.

[0051] When the draft depth of the rod barrel in the logging changes and causes the state to change, the position of the underwater component in the logging can be adjusted by the rope. Therefore, this solution is applicable to the measurement of the groundwater level in the case of a large change in the liquid level position in the logging. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 It is a schematic diagram of a specific application embodiment of the groundwater level engineering exploration system described in this solution;

[0053] Figure 2Schematic diagram of a specific application and implementation example of the groundwater level engineering exploration system described in this solution, different from Figure 1 In this schematic diagram, the filter screen is omitted;

[0054] Figure 3 Cross-sectional view of a specific embodiment of the underwater component described in this solution;

[0055] Figure 4 is Figure 3 Partial enlarged view of part A in

[0056] The reference numerals in the figure are respectively: 1, drum module; 2, rope; 3, limit wheel; 4, support structure; 5, measurement module; 6, casing; 7, underwater component; 71, rod barrel; 72, detection module; 73, rod hole; 74, communication hole; 75, floating body; 76, pull rod; 77, water isolation chamber; 78, tension sensor; 79, first partition board; 710, second partition board; 711, tensioning bolt; 712, elastic rope. Specific implementation manners

[0057] The present invention will be further described in detail below in conjunction with embodiments, but the present invention is not limited to the following embodiments: Embodiment

[0058] As Figures 1 to 4 shown, a groundwater level engineering exploration method based on the well point measurement method, which realizes the measurement of the groundwater level in the logging well based on the rope 2, the measurement module 5 and the underwater component 7. Among them, the underwater component 7 is connected to the lower end of the rope 2, and the measurement module 5 is used to measure the length of the rope 2 released in the logging well. The underwater component 7 includes a rod barrel 71, a floating body 75 and a detection module 72. The upper end of the rod barrel 71 is connected to the lower end of the rope 2, the floating body 75 is arranged in the rod hole 73 of the rod barrel 71, and the rod hole 73 is communicated with the outside of the rod barrel 71 through the communication hole 74;

[0059] In this method, the underwater component 7 is installed in the logging well, specifically: the rod barrel 71 is suspended in the logging well through the rope 2 and kept plumb, the detection module 72 is installed on the rod barrel 71, and the rod hole 73 has a state where the lower end is below the logging well liquid level, the upper end is above the logging well liquid level, and the floating body 75 floats on the logging well liquid surface;

[0060] In this method, the method for obtaining the groundwater level is: the measurement module 5 obtains the position of the rod barrel 71 in the logging well by measuring the length of the rope 2 released in the logging well; the detection module 72 obtains the position of the floating body 75 on the rod barrel 71; according to the position of the rod barrel 71 in the logging well and the position of the floating body 75 on the rod barrel 71, the position of the floating body 75 relative to the logging well wellhead is obtained and this position is used as the position of the groundwater level in the logging well;

[0061] During the underground water level measurement process, the rod barrel 71 is lifted or released through the rope 2 to maintain the states of the rod hole 73 and the floating body 75 relative to the well logging liquid level.

[0062] In the application where precipitation wells, recharge wells / recharge ditches are arranged around the well logging (measurement well for underground water level measurement), it is necessary to make the water level lines in the areas between the precipitation wells and the recharge ditches and between the precipitation wells and the recharge wells inclined. During the process of adjusting the influence of the precipitation wells, recharge wells / recharge ditches on the underground water level, the liquid level in the well logging is affected by the precipitation wells, recharge wells / recharge ditches, and there are obvious changes in the underground water level in the well logging during the measurement period. When using the relatively low-cost and relatively high-precision sounding rope method to measure the liquid level position of this type of well logging, it is not convenient to complete continuous monitoring of the liquid level position. When using the relatively low-cost float method to continuously measure the liquid level in the well logging, the frequent fluctuations of the liquid level will cause the measurement accuracy to be too poor. Based on the above, a technical solution for underground water level engineering exploration that combines the sounding rope method and the float method is provided, aiming to provide an underground water level measurement solution with the characteristics of low implementation cost and guaranteed water level measurement accuracy.

[0063] The principle of this solution to achieve underground water level measurement is as follows: When the underwater component 7 is suspended in the well logging with the rod barrel 71 in the plumb state based on the rope 2, at this time, the measurement module 5 can obtain the current position of the rod barrel 71 in the well logging by releasing the length of the rope 2 in the well logging; Since the rod barrel 71 has a certain length, and currently the rod hole 73 has a state where the lower end is below the well logging liquid level, the upper end is above the well logging liquid level, and the floating body 75 floats on the well logging liquid level. Therefore, when the well logging liquid level fluctuates with the change of the underground water level line, with the position of the rod barrel 71 in the well logging remaining unchanged, because the floating body 75 can float up and down along the rod hole 73 to a certain extent with the well logging liquid level. After obtaining the position of the floating body 75 on the rod barrel 71 through the detection module 72, the position of the floating body 75 in the well logging can be obtained by combining the above two positions, and this position is used as the position of the well logging liquid level. When the height of the well logging liquid level changes such that the floating body 75 cannot move further down or up along the rod hole 73 in the rod barrel 71 or the floating body 75 does not float on the well logging liquid level, by lifting or releasing the rod barrel 71 through the rope 2, the state where the floating body 75 can continuously measure the well logging liquid level position within a certain stroke range can be restored.

[0064] Different from the float method and the rope measuring method used in the prior art, in this solution, after the underwater component 7 is released to a suitable position (in the state), the position of the well logging liquid surface is finally obtained by utilizing the movement of the float 75 within a certain range and the position of the float 75 being detected by the detection module 72 installed on the rod barrel 71. Therefore, compared with the existing rope measuring method for measuring the well logging liquid level, it is not necessary to lift or release the rope 2 for obtaining a single liquid level value, that is, the underwater component 7 can continuously measure the well logging liquid level within a certain range after it is in place once; the water In the structural design and functional design of the lower component 7, the detection module 72 obtains the position of the float 75 on the rod barrel 71 and is not affected by the rope 2, etc., that is, the problem of result lag and poor accuracy caused by transmission resistance during the float method of measuring groundwater level is eliminated because the float needs to pull the rope 2 to move; when the draft of the rod barrel 71 changes in the well logging, resulting in the change of the state, the position of the underwater component 7 in the well logging can be adjusted by the rope 2, so this solution is suitable for groundwater level measurement when the liquid surface position changes drastically in the well logging.

[0065] In a specific application, in order to enable the underwater component 7 to be released and lifted smoothly and reduce the interference of factors such as well wall collapse on the movement of the float 75 with the liquid surface, before the underwater component 7 is installed in the well logging, a casing 6 as a well logging wall protection pipe is installed in the well logging. The side wall of the casing 6 has a pipe hole, which serves as a connecting hole 74 between the liquid surface in the casing 6 and the peripheral geological liquid level line. After the installation of the casing 6 is completed, the water body in the well logging is left to stand. When the water body is clear, the underwater component 7 is installed in the well logging to prevent sediment sedimentation from interfering with the smooth rise and fall of the float 75. Example

[0066] This embodiment is further refined on the basis of embodiment 1:

[0067] The method for maintaining the state of the rod hole 73 and the float 75 relative to the logging liquid level is as follows: the draft of the rod barrel 71 in the logging is determined, and when the draft is less than or equal to the lower limit threshold, the rope 2 releases the rod barrel 71 and makes the draft of the rod barrel 71 reach the set depth; when the draft is greater than or equal to the upper limit threshold, the rope 2 lifts the rod barrel 71 and makes the draft of the rod barrel 71 reach the set depth;

[0068] The method for determining the draft is any one of the following methods:

[0069] This is achieved based on the position of the float 75 on the rod barrel 71 acquired by the detection module 72;

[0070] This is achieved by installing liquid level switches at the upper and lower ends of the rod barrel 71 .

[0071] It is easy to understand that the rod barrel 71 is structured to sink into the well logging without the pulling of the rope 2. After the rod barrel 71 is held at a specific position in the well logging under the pulling of the rope 2, as the liquid level in the well logging changes, the floating body 75 will rise or fall along the rod hole 73 with the liquid surface. When the liquid level drops too much, the floating body 75 will sink to the bottom of the rod barrel 71, resulting in the floating body 75 being restricted by the rod barrel 71 and unable to further descend with the liquid surface. When the liquid level rises too much, the floating body 75 will rise to the top of the rod barrel 71, resulting in the floating body 75 being restricted by the rod barrel 71 and unable to further rise with the liquid surface. The change in the above liquid level position is accompanied by the change in the draft depth of the rod barrel 71 in the well logging. The above solution provides a specific method for monitoring the state change. Specifically, match the lower limit threshold, set depth, and upper limit threshold associated with the draft depth. The lower limit threshold and the upper limit threshold are used as trigger values to release the rod barrel 71 by the rope 2 and lift the rod barrel 71. After the draft depth reaches the corresponding threshold and triggers the action of the rope 2, the rod barrel 71 is lowered or lifted to the set depth where the floating body 75 can rise and fall to adapt to the rise and fall of the liquid level for groundwater measurement.

[0072] In this embodiment, since the position of the floating body 75 in the rod barrel 71 changes with the change of the draft depth, the detection value of the detection module 72 can be used as the determination basis for the draft depth. A separate liquid level switch can also be configured for the rod barrel 71. For example, by setting liquid level switches at the upper end and the lower end of the rod barrel 71 respectively, the determination of whether the upper limit threshold is reached and whether the lower limit threshold is reached can be realized. Embodiment

[0073] This embodiment is further refined on the basis of Embodiment 1:

[0074] The method for the measurement module 5 to obtain the position of the rod barrel 71 in the well logging is as follows: By obtaining the number of rolling circles of the roller in contact with the rope 2 on the measurement module 5, the length of the rope 2 released in the well logging is obtained. Among them, the roller is configured to be set at the well logging wellhead position, and the wheel surface of the roller is in contact with the side surface of the rope 2. When the rope 2 is lifted and released, the roller rotates under the friction force of the rope 2 and synchronizes with the movement speed of the rope 2;

[0075] The method for the detection module 72 to obtain the position of the floating body 75 on the rod barrel 71 is any one or several of the following methods:

[0076] A permanent magnet is provided in the floating body 75. When the permanent magnet moves relative to the rod barrel 71 along the rod hole 73 with the floating body 75, the detection module 72 obtains the position of the floating body 75 on the rod barrel 71 by sensing the magnetic field of the permanent magnet;

[0077] The bottom of the floating body 75 is connected to a tension sensor 78 provided at the bottom of the rod barrel 71 through an elastic cord 712 or a constant-force spring. The tension sensor 78 is used to measure the tension exerted on it by the floating body 75. The detection module 72 converts the tension into the elongation of the elastic cord 712 or the constant-force spring, and calculates the position of the floating body 75 on the rod barrel 71 according to the elongation.

[0078] The above solution provides a specific method for the measurement module 5 to obtain the position of the rod barrel 71 during well logging. The principle is as follows: When the rope 2 is lifted or lowered, the friction between the rope 2 and the roller forces the roller to move with the rope 2. According to the rotation direction of the roller, it can be determined whether the rope 2 is being lowered or lifted. According to the number of rotations and the angle of the roller, the lifting amount or lowering amount of the rope 2 can be determined. In this measurement method, the measurement of the position of the rod barrel 71 is not affected by the winding radius of the rope 2 on the following drum module, nor by the shape of the turns of the rope 2 on the drum module. On the premise of a simple solution, the position of the rod barrel 71 during well logging can be correctly obtained. A preferred application is to clamp the rope 2 with two rollers. Each roller is a metal wheel with a ring groove on its wheel surface, and a rubber layer is provided on the groove surface of the ring groove, and a wear-resistant cloth surface layer is provided on the surface of the rubber layer. The rubber layer undergoes elastic deformation under the extrusion of the rope 2. By adopting this solution, a reliable supporting force can be maintained between the rope 2 and the wheel surface so that the roller can move synchronously with the rope 2. The wear-resistant cloth surface layer is used to adapt to the rope 2 made of steel wire rope, and keep the performance of the measurement module 5 reliable for a long time.

[0079] The above solution provides a specific method for the detection module 72 to obtain the position of the floating body 75 on the rod tube 71. The principle is as follows: For the floating body 75 provided with a permanent magnet, when the floating body 75 moves with the liquid level position, the permanent magnet moves in the rod tube 71 along with the floating body 75. In this way, the detection module 72 obtains the position of the floating body 75 through magnetic induction. The detection module 72 can adopt structures such as magnetic induction coils and waveguide wires; for the floating body 75 connected to the bottom of the rod tube 71 through an elastic rope 712 or a constant force spring, as the floating body 75 moves, the elongation of the elastic rope 712 or the constant force spring changes. At this time, the force exerted by the elastic rope 712 or the constant force spring on the tension sensor 78 changes. Therefore, based on the measurement result of the tension sensor 78, it can be converted into the position of the floating body 75 on the rod tube 71. Compared with magnetic induction coils and waveguide wires, this structure not only has the characteristics of low cost, but also has a simple supporting structure, the measurement accuracy is not easily affected by the electromagnetic field in the environment, low power consumption, and convenient power supply. Preferably, since the draft depth of the floating body 75 will change after the elongation of the elastic rope 712 or the constant force spring changes, when determining the logging liquid level position through the position of the floating body 75 on the rod tube 71, the measurement result of the tension sensor 78 is used to correct the logging liquid level position. Preferably, the floating body 75 is set as a cylindrical structure with an equal diameter in the draft section. Since there is a matching relationship between the tension and the buoyancy, it can be set to obtain the correction coefficient K through experiments. This K value is used to eliminate the influence of the floating body 75 under different tensions and draft depths on the measurement result of the underground water level. Embodiment

[0080] This embodiment is further refined on the basis of Embodiment 1:

[0081] The lifting or releasing of the rod tube 71 by the rope 2 is realized under the action of the drum module. The upper end of the rope 2 is wound on the drum module. When the position of the rod tube 71 in the logging is fixed, the measurement value of the measurement module 5 is read and stored. When the position of the rod tube 71 changes, the measurement value of the measurement module 5 is read and stored again;

[0082] The detection module 72 obtains the position of the floating body 75 on the rod tube 71 according to the set measurement frequency. After the detection module 72 completes the position detection of the floating body 75 on the rod tube 71 each time, it transmits the position detection result of the floating body 75 on the rod tube 71 to the processing module. The processing module obtains the position of the underground water level in the logging according to the currently stored measurement value and the current detection result, and uses the detection result as the determination basis for the operation of the drum module. The operation of the drum module is used to maintain the states of the rod hole 73 and the floating body 75 relative to the logging liquid level.

[0083] The above solution provides a technical solution in which the position of the rod tube 71 during well logging depends on the implementation of the drum module 1. It provides a technical solution for recording the measured value of the measurement module 5 after the drum module completes a single action, so that when calculating the groundwater level during well logging, the position of the rod tube 71 can be efficiently read. It provides a technical solution for using the position detection result of the detection module 72 as the basis for measuring the groundwater level during well logging and judging the operation of the drum module. Specifically, the storage location of the measured value can be stored on the rope 2 processing module. After the detection module 72 completes the position detection of the floating body 75 once, it immediately uploads the detection result to the processing module to calculate the groundwater level, complete a groundwater level measurement, complete a determination of the water intake depth of the rod tube 71, and determine whether to adjust the position of the rod tube 71 relative to the liquid level in the well logging through the drum module. Embodiment

[0084] Based on Embodiment 1, this embodiment provides a groundwater level engineering exploration system based on the well point measurement method, which is used to implement the groundwater level engineering exploration method described in any one of the above. It is easy to understand that this groundwater level engineering exploration system is a groundwater level engineering exploration system for implementing the above groundwater level engineering exploration method. Embodiment

[0085] This embodiment is further refined on the basis of Embodiment 5:

[0086] The groundwater level engineering exploration system includes a rope 2, a measurement module 5, and an underwater component 7. The underwater component 7 is connected to the lower end of the rope 2. The measurement module 5 is used to measure the length of the rope 2 released in the well logging. The underwater component 7 includes a rod tube 71, a floating body 75, and a detection module 72. The upper end of the rod tube 71 is connected to the lower end of the rope 2. The floating body 75 is arranged in the rod hole 73 of the rod tube 71. The rod hole 73 is communicated with the outside of the rod tube 71 through a communication hole 74. The detection module 72 is installed on the rod tube 71, and the detection module 72 is used to obtain the position of the floating body 75 on the rod tube 71;

[0087] The rod tube 71 is a mesh tube, and further includes a filter screen wrapped outside the rod tube 71. The mesh holes on the mesh tube serve as the communication holes 74, and the filter screen covers each communication hole 74;

[0088] Both the upper end and the lower end of the floating body 75 are elliptical head-shaped structures that protrude outward relative to the ends.

[0089] This solution is different from the above solutions. A technical solution is provided that uses a perforated pipe as the rod barrel 71. The perforated pipe not only enables the rod hole 73 to have good water body connectivity with the logging, but also provides a solution for the rod barrel 71 with strong structural stability. The filter screen is used to prevent impurities in the logging from entering the rod hole 73, avoiding, for example, the deposition of impurities around the floating body 75, the sinking or floating objects entrained in the communication hole 74, which may affect the sensitivity of the floating body 75 rising or falling relative to the rod barrel 71. The end shape of the floating body 75 is used to achieve: to reduce the influence of the shaking of the floating body 75 in the rod barrel 71 on the position detection of the floating body 75. When the floating body 75 has a small clearance fit with the rod hole 73, by avoiding the obstruction at the end when the floating body 75 moves relative to the rod barrel 71, the end shape can effectively ensure the sensitivity of the floating body 75 rising or falling relative to the rod barrel 71. From the perspective of the movement sensitivity of the floating body 75, an arc chamfer can be set at the end position of the floating body 75 to replace the elliptical head-like structure. However, when the top surface of the floating body 75 is a plane, the influence of water droplets falling on this plane on the position of the floating body 75 will be much greater than the influence of water droplets falling on the elliptical head-like structure on the position of the floating body 75. Embodiment

[0090] This embodiment is further refined on the basis of Embodiment 6:

[0091] A first partition 79 is provided at the bottom of the rod barrel 71 and a second partition 710 is provided below the first partition 79. The first partition 79 and the second partition 710 form a water isolation chamber 77 inside the rod barrel 71. The detection module 72 includes a tension sensor 78. The lower end of the tension sensor 78 is fixedly connected to the second partition 710, and the upper end of the tension sensor 78 is fixedly connected to a pull rod 76. The pull rod 76 passes through the first partition 79 through a through hole in the first partition 79, and an O-ring is provided between the hole wall of the through hole and the pull rod 76;

[0092] The lower end of the floating body 75 is connected to the upper end of the pull rod 76 by an elastic cord 712 or a constant force spring.

[0093] The above solution provides a technical solution for enclosing the electronic devices of the detection module 72 in a water isolation chamber 77 to facilitate the selection of corresponding electronic devices and ensure the reliability of their performance. Specifically, the pull rod 76 serves as a rigid rod and an intermediate connecting member for transmitting force between the tension sensor 78 and the elastic cord 712 or the constant force spring. Compared with the situation where the elastic cord 712 or the constant force spring passes through the through hole, since the pull rod 76 does not deform when being pulled, from the perspective of the gap between the sealing hole wall and the pull rod 76, it is easier to obtain reliable sealing performance and smaller movement resistance of the pull rod 76 in this solution; the O-ring serves as the sealing structure at the position of the through hole. When the tension sensor 78 is deformed by pulling, compared with a packing sealing structure, this sealing structure can reduce the movement resistance of the pull rod 76 to improve the measurement accuracy of the tension sensor 78. A preferred solution is to have multiple O-rings along the axis direction of the through hole, and use the O-ring at the upper part to block sand grains and the like from entering the mating surface between the O-ring at the lower part and the pull rod 76, thereby ensuring the sealing reliability of the water isolation chamber 77. Embodiment

[0094] This embodiment is further refined on the basis of Embodiment 7:

[0095] The rod barrel 71 includes a first barrel body, a second barrel body, and an end cap that are sequentially connected from top to bottom. The first barrel body and the second barrel body form a threaded connection relationship through connecting threads, and the second barrel body and the end cap form a threaded connection relationship through connecting threads;

[0096] The first partition plate 79 is fixed at the lower end of the first barrel body, and the second partition plate 710 is fixed at the lower end of the second barrel body. Central holes are provided on both the first partition plate 79 and the second partition plate 710. The central hole on the first partition plate 79 serves as the through hole, and the tension sensor 78 and the second partition plate 710 are fixedly connected by a tension bolt 711. The central hole on the second partition plate 710 serves as the bolt hole for the tension bolt 711;

[0097] An installation cavity for installing a signal transmission module and a storage battery is formed between the second partition plate 710 and the end cap.

[0098] This solution provides a technical solution for facilitating the assembly of an underwater component 7. Specifically, after embedding a floating body 75 with an elastic cord 712 or a constant force spring connected to its lower end into the rod hole 73 from the upper end of the first cylinder, the lower end of the elastic cord 712 or the constant force spring passes through the through hole and through the first partition 79. After connecting the elastic cord 712 or the constant force spring to the pull rod 76 at the lower end of the first cylinder, a tension sensor 78 is installed from the lower end of the first cylinder, and the pull rod 76 passes through the through hole and through the first partition 79. At this time, the tension sensor 78 is in a centered state in the first cylinder. Then, the second cylinder is connected to the lower end of the first cylinder. After the second cylinder is docked, the bolt hole at the lower end of the tension sensor 78 is aligned with the central hole on the second partition 710. At this time, a tightening bolt 711 is installed from the bottom side of the second partition 710, and the fixation of the bottom of the tension sensor 78 on the second partition 710 can be completed. Then, electronic devices such as a signal transmission module and a storage battery are placed in the enclosed space formed by the end cap and the second partition 710, and the enclosed space is further closed by rotating the end cap. In specific implementation, thread sealant is applied to the connection surface between the first cylinder and the second cylinder and the connection surface between the second cylinder and the end cap. The thread sealant is used to achieve water isolation and anti-loosening. Embodiment

[0099] This embodiment is further refined based on Embodiment 6:

[0100] It further includes a drum module, the upper end of the rope 2 is wound around the drum module, and it also includes a driving device for driving the drum module to rotate;

[0101] It further includes a signal transmission module. The signal transmission module receives the floating body 75 position detection result of the detection module 72 and transmits this position detection result to the control module of the driving device. The control module is used to: control the operation of the drum module and maintain the state of the rod hole 73 and the floating body 75 relative to the well logging liquid level.

[0102] In the above solution, the driving device and the drum module enable the adjustment of the length of the rope 2 released in the well logging to be completed through automatic control, so that this system has the characteristic of unattended operation during the underground water level monitoring process. The signal transmission module is used to establish an automatic control strategy for the position of the floating body 75 and the position of the rod barrel 71.

[0103] Embodiment 10:

[0104] This embodiment is further refined based on Embodiment 9:

[0105] It further includes a support structure 4 and a limit wheel 3. The drum module, the limit wheel 3, and the measurement module 5 are all installed on the support structure 4. The rope 2 between the drum module and the measurement module 5 is supported by the limit wheel 3;

[0106] The rope 2 is a steel wire rope;

[0107] A biofilm inhibition coating is provided on the inner wall of the rod barrel 71 and / or the outer wall of the floating body 75.

[0108] In the above solution, the limit wheel 3 serves as a reversing wheel for the rope 2, so that when the rope 2 is wound around different axial positions of the drum module 1 or released from different axial positions of the drum module 1, the ropes 2 on both sides of the measuring module 5 have a stable angle. Preferably, under the action of the limit wheel 3, the ropes 2 on both sides of the measuring module 5 are in a straight state; the steel wire rope enables the rope 2 to have a relatively small elongation under the tension of the underwater component 7, thereby ensuring the acquisition and detection accuracy of the measuring module 5 for the rod barrel 71. The biofilm inhibition coating is used to inhibit the biofilm that may form on the inner wall of the rod barrel 71 and / or the outer wall of the floating body 75, thereby ensuring the reliability and sensitivity of the floating body 75 to rise and fall with the logging liquid level.

[0109] The above content is a further detailed description of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific embodiments of the present invention are only limited to these descriptions. For those of ordinary skill in the technical field to which the present invention belongs, other embodiments obtained without departing from the technical solution of the present invention should all be included within the protection scope of the present invention.

Claims

1. A method for underground water level engineering survey based on a well point measurement method, the method realizing underground water level measurement in well logging based on a rope (2), a measurement module (5) and an underwater component (7), wherein: The underwater component (7) is connected to the lower end of the rope (2), and the measuring module (5) is used to measure the length of the rope (2) released in the well logging, characterized in that the underwater component (7) comprises a rod barrel (71), a float (75) and a detection module (72), the upper end of the rod barrel (71) is connected to the lower end of the rope (2), the float (75) is arranged in the rod hole (73) of the rod barrel (71), and the rod hole (73) is connected to the outside of the rod barrel (71) through a connecting hole (74); In the method, the underwater component (7) is installed in the well logging, specifically: the rod barrel (71) is suspended in the well logging by a rope (2) and holds a plumb bob, the detection module (72) is installed on the rod barrel (71), the rod hole (73) has a lower end located below the well logging liquid surface, an upper end located above the well logging liquid surface, and a float (75) floats on the well logging liquid surface; In the method, the method for obtaining the groundwater level is as follows: the measuring module (5) obtains the position of the rod barrel (71) in the well logging by releasing the length of the rope (2) in the well logging; the detection module (72) obtains the position of the float (75) on the rod barrel (71); based on the position of the rod barrel (71) in the well logging and the position of the float (75) on the rod barrel (71), the position of the float (75) relative to the well logging wellhead is obtained and the position is used as the position of the groundwater level in the well logging; During the underground water level measurement process, the rod barrel (71) is lifted or released by the rope (2) to maintain the state of the rod hole (73) and the float (75) relative to the logging liquid surface, wherein the rod hole (73) has a lower end below the logging liquid surface, an upper end above the logging liquid surface, and the float (75) floats on the logging liquid surface; The bottom of the floating body (75) is connected to a tension sensor (78) arranged at the bottom of the rod barrel (71) via an elastic rope (712) or a constant force spring. The tension sensor (78) is used to measure the tension exerted by the floating body (75) on it. The detection module (72) converts the tension into an elongation of the elastic rope (712) or the constant force spring, and calculates the position of the floating body (75) on the rod barrel (71) based on the elongation. The draft section of the float (75) is an equal-diameter columnar structure. When the position of the logging liquid level is determined by the position of the float (75) on the rod barrel (71), the logging liquid level position is corrected using the measurement result of the tension sensor (78): a correction coefficient K is obtained through experiments, and the K value is used to eliminate the influence of the float (75) on the groundwater level measurement result under different tensions and draft depths. The upper end and the lower end of the float (75) are both elliptical head-shaped structures that are convex relative to the end.

2. The underground water level engineering survey method based on the well point measurement method according to claim 1 is characterized in that: The method for maintaining the state of the rod hole (73) and the float (75) relative to the logging fluid surface is as follows: determining the draft of the rod barrel (71) in the logging process; when the draft is less than or equal to a lower limit threshold, the rope (2) releases the rod barrel (71) and makes the draft of the rod barrel (71) reach a set depth; when the draft is greater than or equal to an upper limit threshold, the rope (2) lifts the rod barrel (71) and makes the draft of the rod barrel (71) reach a set depth; The method for determining the draft is any one of the following methods: This is achieved according to the position of the float (75) on the rod barrel (71) acquired by the detection module (72); This is achieved by installing liquid level switches at the upper and lower ends of the rod barrel (71).

3. The underground water level engineering survey method based on the well point measurement method according to claim 1 is characterized in that: The method for the measuring module (5) to obtain the position of the rod barrel (71) in the well logging is: by obtaining the number of rolling circles of the roller on the measuring module (5) that contacts the rope (2), the length of the rope (2) released in the well logging is obtained, wherein the roller is configured as follows: set at the wellhead position of the well logging, the wheel surface of the roller contacts the side of the rope (2), and when the rope (2) is lifted and released, the roller rotates under the friction force of the rope (2) and is synchronized with the movement speed of the rope (2).

4. The underground water level engineering survey method based on the well point measurement method according to claim 1 is characterized in that: The rope (2) lifts or releases the rod barrel (71) under the action of the drum module (1), the upper end of the rope (2) is wound around the drum module (1), and when the position of the rod barrel (71) in the well logging is fixed, the measurement value of the measurement module (5) is read and stored; when the position of the rod barrel (71) changes, the measurement value of the measurement module (5) is read and stored again; The detection module (72) obtains the position of the float (75) on the rod barrel (71) according to a set measurement frequency. After the detection module (72) completes the position detection of the float (75) on the rod barrel (71) each time, it transmits the position detection result of the float (75) on the rod barrel (71) to the processing module. The processing module obtains the position of the groundwater level in the well logging according to the currently stored measurement value and the current detection result, and uses the detection result as a basis for determining the operation of the roller module (1). The roller module (1) is used to maintain the state of the rod hole (73) and the float (75) relative to the well logging liquid surface.

5. The underground water level engineering survey system based on the well point measurement method is characterized by: The system is used to implement the groundwater level engineering survey method described in any one of claims 1 to 4.

6. The underground water level engineering survey system based on the well point measurement method according to claim 5 is characterized in that: The underground water level engineering survey system comprises a rope (2), a measuring module (5) and an underwater component (7), wherein the underwater component (7) is connected to the lower end of the rope (2), the measuring module (5) is used to measure the length of the rope (2) released in the well logging, and the underwater component (7) comprises a rod barrel (71), a floating body (75) and a detection module (72), wherein the upper end of the rod barrel (71) is connected to the lower end of the rope (2), the floating body (75) is arranged in a rod hole (73) of the rod barrel (71), the rod hole (73) is connected to the outside of the rod barrel (71) through a connecting hole (74), and the detection module (72) is installed on the rod barrel (71), and the detection module (72) is used to obtain the position of the floating body (75) on the rod barrel (71); The rod barrel (71) is a mesh tube, and further comprises a filter screen wrapped around the outside of the rod barrel (71); the mesh holes on the mesh tube serve as the communication holes (74), and the filter screen covers each communication hole (74).

7. The underground water level engineering survey system based on the well point measurement method according to claim 5 or 6, characterized in that: The bottom of the rod barrel (71) is provided with a first partition (79) and a second partition (710) located below the first partition (79), the first partition (79) and the second partition (710) form a watertight chamber (77) located inside the rod barrel (71), the detection module (72) includes a tension sensor (78), the lower end of the tension sensor (78) is fixedly connected to the second partition (710), the upper end of the tension sensor (78) is fixedly connected to a pull rod (76), the pull rod (76) passes through the first partition (79) through a through hole on the first partition (79), and an O-ring is provided between the hole wall of the through hole and the pull rod (76); The lower end of the floating body (75) is connected to the upper end of the pull rod (76) via an elastic rope (712) or a constant force spring.

8. The underground water level engineering survey system based on the well point measurement method according to claim 7 is characterized in that: The rod barrel (71) comprises a first barrel body, a second barrel body and an end cap which are sequentially connected from top to bottom, the first barrel body and the second barrel body forming a threaded connection relationship through a connecting thread, and the second barrel body and the end cap forming a threaded connection relationship through a connecting thread; The first baffle (79) is fixed to the lower end of the first cylinder, and the second baffle (710) is fixed to the lower end of the second cylinder. The first baffle (79) and the second baffle (710) are both provided with a central hole, and the central hole on the first baffle (79) serves as the through hole. The tension sensor (78) is fixedly connected to the second baffle (710) by a tension bolt (711), and the central hole on the second baffle (710) serves as a bolt hole for the tension bolt (711); An installation cavity for installing a signal transmission module and a storage battery is formed between the second partition plate (710) and the end cap.

9. The underground water level engineering survey system based on the well point measurement method according to claim 5 or 6, characterized in that: It also comprises a drum module (1), the upper end of the rope (2) being wound around the drum module (1), and a driving device for driving the drum module (1) to rotate; It also includes a signal transmission module, which receives the position detection result of the float (75) from the detection module (72) and transmits the position detection result to the control module of the drive device, and the control module is used to control the operation of the roller module (1) and maintain the state of the rod hole (73) and the float (75) relative to the logging liquid surface.

10. The underground water level engineering survey system based on the well point measurement method according to claim 9, characterized in that: It also comprises a supporting structure (4) and a limiting wheel (3), wherein the roller module (1), the limiting wheel (3) and the measuring module (5) are all mounted on the supporting structure (4), and the rope (2) between the roller module (1) and the measuring module (5) is supported on the limiting wheel (3); The rope (2) is a steel wire rope; A biofilm inhibition coating is provided on the inner wall of the rod barrel (71) and / or the outer wall of the float (75).

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