Device and method for measuring initial diving water level of rock hole wall

Abstract

The invention provides a diving initial water level measuring device and method for a rock hole wall, the diving initial water level measuring device comprises a measuring sleeve and a water pressure gauge, the outer wall of the measuring sleeve is connected with a sealing ring group, the water pressure gauge is located above the sealing ring group, and the sealing ring group comprises a first sealing ring and a second sealing ring which sleeve the outer wall of the measuring sleeve in the axial direction; an air inlet channel and an air outlet channel which extend in the axial direction are formed in the pipe wall of the measuring sleeve, and a first air hole and a second air hole are formed in the measuring sleeve. The outer wall of the measuring sleeve is connected with the sealing ring group, so that a semi-dry and semi-wet drilling mode is realized, a clear water slag carrying function is reserved, identification difficulty caused by full-hole mixing is avoided, and the initial diving water level is distinguished while drilling under the condition of clear water drilling. By means of the air inlet channel and the air outlet channel in the pipe wall of the measuring sleeve, dynamic balance of the sealing effect of the sealing ring set is maintained, and the measuring accuracy of the water column pressure formed after diving infiltration is improved.

Description

Technical Field

[0001] This invention relates to the field of hydrogeological exploration, and in particular to a device for measuring the initial water level of ungrounded boreholes in rock formations. Background Technology

[0002] There are numerous existing methods for measuring water levels, with confined aquifer levels and fluctuating water levels within boreholes being common targets. However, measuring devices for unconfined aquifer initial exposure levels remain scarce. Unconfined aquifer initial exposure levels refer to the groundwater level observed at the top of the aquifer first exposed during drilling. While the initial exposure level of confined aquifers can be measured through changes in water pressure, the unconfined aquifer initial exposure level is difficult to measure using conventional methods due to its low or almost nonexistent pressure, posing a significant challenge to engineering implementation.

[0003] In geological exploration for hydropower, mining, and other engineering projects, drilling depths are generally less than 100 meters, and clear water positive circulation drilling is commonly used. During clear water drilling, both the flushing fluid and the exposed groundwater are "clear water," with identical physical properties, making them highly susceptible to mixing. This makes it impossible to determine the initial groundwater level using conventional methods (such as changes in density, viscosity, and conductivity). While completely dry drilling allows for direct assessment of the water level, it lacks the lubrication and cuttings-carrying capabilities of the flushing fluid, resulting in rapid drill bit wear, low drilling efficiency, and a tendency for borehole wall collapse. Summary of the Invention

[0004] This invention provides a device and method for measuring the initial water level of a submerged borehole in rock formations, thereby solving the problem in the prior art that it is difficult to accurately measure the initial water level of a submerged borehole under clear water drilling conditions.

[0005] This invention provides a device for measuring the initial water level of a submersible borehole in rock formations, comprising a measuring sleeve and a manometer. The measuring sleeve is used for the drill rod to pass through, and a return water gap is provided between the outer wall of the drill rod and the inner wall of the measuring sleeve. A sealing ring assembly is connected to the outer wall of the measuring sleeve. The water pressure gauge is located above the sealing ring assembly. The sealing ring assembly includes a first sealing ring and a second sealing ring that are axially fitted onto the outer wall of the measuring sleeve. An axially extending air inlet channel and an air outlet channel are provided inside the tube wall of the measuring sleeve. A first air hole and a second air hole are opened on the measuring sleeve. The first air hole is located between the first sealing ring and the second sealing ring and is connected to the air inlet channel. The sealing ring assembly is located between the second air hole and the outlet of the measuring sleeve.

[0006] Furthermore, the measuring sleeve is covered with a first isolation net, which covers the first air hole.

[0007] Furthermore, a high-pressure air nozzle is connected to the first air hole, and the outlet of the high-pressure air nozzle faces the first isolation net.

[0008] Furthermore, the measuring sleeve is fitted with a second isolation net, which covers the second air hole.

[0009] Furthermore, it also includes a water pump, an inlet pipe, and an outlet pipe. The water pump is connected to the outside of the measuring sleeve through the inlet pipe. The end of the inlet pipe away from the water pump is located between the first air hole and the second air hole. The water pump is connected to the inside of the measuring sleeve through the outlet pipe. The water pump is used to transport water from the inlet pipe to the outlet pipe.

[0010] Furthermore, a one-way valve is connected to the outlet pipe, which only allows fluid to flow from the water pump to the outlet pipe.

[0011] Furthermore, multiple water immersion sensors are fixedly connected to the pump body of the water pump, and the water immersion sensors are distributed along the vertical direction.

[0012] Furthermore, it also includes a third sealing ring, the second vent is located between the third sealing ring and the sealing ring assembly, the outer wall of the third sealing ring is fitted with a water-stop rubber ring, the water-stop rubber ring is used to fit against the inner wall of the borehole to form a seal, and the water pressure gauge is located above the water-stop rubber ring.

[0013] Furthermore, the material of the water-stopping rubber ring is set to wear-resistant rubber.

[0014] The present invention also provides a method for measuring the initial water level during diving, comprising the following steps: S1: Combine the measuring sleeve with the drill pipe and install it on the drilling rig; S2: Pass drilling fluid into the water inlet channel of the drill pipe and air into the air inlet channel to balance the air pressure with the water pressure below the sealing ring assembly; S3: When drilling reaches the water-bearing layer, the pressure gauge detects a sudden change in pressure reading that continues to increase as drilling progresses, indicating that drilling has reached the water-bearing layer.

[0015] The beneficial effects of this invention are as follows: 1. By connecting a sealing ring assembly to the outer wall of the measuring casing, a semi-dry and semi-wet drilling method is achieved, which retains the function of carrying slag with clean water and avoids the identification difficulties caused by mixing throughout the hole. Under the condition of clean water drilling, the initial water level of the submerged water can be determined while drilling.

[0016] 2. By maintaining the dynamic balance of the sealing effect of the sealing ring assembly through the air inlet and outlet channels inside the measuring casing wall, the accuracy of measuring the water column pressure formed after the diving infiltration is improved.

[0017] 3. The device is lowered directly into the drill pipe and monitors water pressure and flow rate in real time during drilling. It automatically identifies the water level when drilling reaches the phreatic layer, eliminating the need to pull out the drill string and change to a special measuring tool, thus significantly shortening the construction period. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall distribution of the drill pipe and measuring casing in an embodiment of the present invention.

[0019] Figure 2 yes Figure 1 Enlarged diagram of point A in the middle.

[0020] Figure 3 This is a schematic diagram showing the positional relationship of the water outlet pipe in an embodiment of the present invention.

[0021] Figure 4 This is a schematic diagram of the connection relationship of the third sealing ring in an embodiment of the present invention.

[0022] Figure 5 This is a schematic diagram of the cable connection relationship in an embodiment of the present invention.

[0023] Figure 6 This is a schematic diagram showing the distribution of the water immersion sensors according to an embodiment of the present invention.

[0024] Figure label: 1. Drill rod; 11. Water inlet channel; 12. Drill bit; 2. Measuring sleeve; 21. Water return gap; 22. Air inlet channel; 23. Air outlet channel; 24. First air hole; 241. High-pressure air nozzle; 25. Second air hole; 3. Sealing ring assembly; 31. First sealing ring; 32. Second sealing ring; 4. Water pressure gauge; 5. First isolation net; 6. Second isolation net; 7. Water pump; 71. Water inlet pipe; 72. Water outlet pipe; 73. One-way valve; 74. Water immersion sensor; 8. Third sealing ring; 81. Water-stop rubber ring; 9. Cable; 91. Plug; 92. Socket. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0026] The terms "first" and "second" in the specification and claims of this invention may explicitly or implicitly include one or more of those features. In the description of this invention, unless otherwise stated, "a plurality of" means two or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0027] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0028] The following is combined Figures 1-6 This invention describes a device for measuring the initial water level of a submersible borehole in rock formations. The device includes a measuring sleeve 2 and a manometer 4. The measuring sleeve 2 allows a drill rod 1 to pass through, and a return water gap 21 is provided between the outer wall of the drill rod 1 and the inner wall of the measuring sleeve 2. A sealing ring assembly 3 is connected to the outer wall of the measuring sleeve 2, and the manometer 4 is located above the sealing ring assembly 3. The sealing ring assembly 3 includes a first sealing ring 31 and a second sealing ring 32 axially fitted onto the outer wall of the measuring sleeve 2. An axially extending air inlet channel 22 and an air outlet channel 23 are provided within the wall of the measuring sleeve 2. A first air hole 24 and a second air hole 25 are provided on the measuring sleeve 2. The first air hole 24 is located between the first sealing ring 31 and the second sealing ring 32 and communicates with the air inlet channel 22. The sealing ring assembly 3 is located between the second air hole 25 and the outlet of the measuring sleeve 2.

[0029] Specifically, such as Figure 1 , Figure 2 As shown, a sealing ring assembly 3 is fixedly connected to the outer wall of the measuring sleeve 2. The sealing ring assembly 3 divides the measuring sleeve 2 into a water drilling area below the sealing ring assembly 3 and a dry drilling area above the sealing rings. A double-layered hollow channel is provided inside the wall of the measuring sleeve 2. The inner channel is designated as an air inlet channel 22 for the introduction of high-pressure gas. The outer channel is designated as an air outlet channel 23 for connecting to negative pressure. A first air hole 24, connected to the air inlet channel 22, is opened on the wall of the measuring sleeve 2 for the discharge of high-pressure gas. A second air hole 25, connected to the air outlet channel 23, is opened on the wall of the measuring sleeve 2 for the intake of gas or liquid. The sealing ring assembly 3 consists of a first sealing ring 31 and a second sealing ring 32. The first air hole 24 is located between the first sealing ring 31 and the second sealing ring 32, and the second air hole 25 is located above the sealing ring assembly 3. A water pressure gauge 4 is located above the sealing ring assembly 3 and can accurately capture the water column pressure formed after diving infiltration.

[0030] When using the underwater initial water level measurement device, the drill rod 1 passes through the measuring sleeve 2, extends from the outlet end of the measuring sleeve 2, and connects to the drill bit 12. The drill bit 12 is 0.3~0.4m away from the outlet end of the measuring sleeve 2. A water inlet channel 11 is provided inside the drill rod 1, and a return water gap 21 is formed between the outer wall of the drill rod 1 and the inner wall of the measuring sleeve 2. During drilling, clean water is injected from the water inlet channel 11 and discharged from the end of the drill bit 12, and then returns to the surface through the return water gap 21. High-pressure gas is ejected from the first vent 24 to fill the gap between the sealing ring assembly 3 and the borehole wall. The sealing ring assembly 3 is configured as a first sealing ring 31 and a second sealing ring 32, and the gap between the outer walls of the first sealing ring 31 and the second sealing ring 32 and the borehole wall is set to 5mm-10mm.

[0031] High-pressure gas is injected through the first vent 24, flowing downwards into the gap between the first sealing ring 31 and the borehole wall to balance the water column pressure within this gap, preventing water leakage upwards into the dry drilling area. It then flows upwards through the gap between the first sealing ring 31 and the borehole wall, escapes through the second vent 25, and is finally discharged to the ground via the vent channel 23, maintaining the stability of the dynamic seal. When drilling reaches the groundwater layer and the initial water level is located in the space where the pressure gauge 4 is located, the injected water will continuously overflow into the dry drilling area. The depth of the groundwater level can be calculated by converting the water column pressure. This allows for accurate measurement of the initial groundwater level under clean water drilling conditions.

[0032] Furthermore, the measuring sleeve 2 is covered with a first isolation net 5, which covers the first air hole 24.

[0033] Specifically, such as Figure 2 As shown, the first vent 24 is the high-pressure gas outlet; if rock debris or silt enters, it will cause blockage of the gas path. The first isolation net 5 can intercept particles, ensuring a continuous and stable ejection of high-pressure gas and maintaining the reliability of the dynamic seal.

[0034] Furthermore, a high-pressure air nozzle 241 is connected to the first air hole 24, and the outlet of the high-pressure air nozzle 241 faces the first isolation net 5.

[0035] Specifically, such as Figure 2 As shown, multiple first air holes 24 are arranged along the axial direction. Each first air hole 24 is connected to a high-pressure air nozzle 241. The high-pressure air nozzle 241 concentrates the gas and guides it to the isolation net, which can backwash the rock debris attached to the net surface, achieve self-cleaning, further reduce the risk of blockage, and extend the continuous operation time.

[0036] Furthermore, the measuring sleeve 2 is covered with a second isolation net 6, which covers the second vent 25.

[0037] Specifically, such as Figure 2As shown, the second vent 25 is a gas escape channel, and the second isolation net 6 prevents rock debris from falling into the vent from above, avoids blockage of the gas outlet channel 23, and ensures smooth gas circulation.

[0038] Furthermore, it also includes a water pump 7, an inlet pipe 71, and an outlet pipe 72. The water pump 7 is connected to the outside of the measuring sleeve 2 through the inlet pipe 71. The end of the inlet pipe 71 away from the water pump 7 is located between the first air hole 24 and the second air hole 25. The water pump 7 is connected to the inside of the measuring sleeve 2 through the outlet pipe 72. The water pump 7 is used to transport water from the inlet pipe 71 to the outlet pipe 72.

[0039] Specifically, such as Figure 2 , Figure 3 As shown, the end of the inlet pipe 71 is connected to the top of the second sealing ring 32, enabling communication with the outside of the measuring sleeve 2, while the outlet pipe 72 is connected to the inside of the measuring sleeve 2. When clean water injected from the inlet channel 11 seeps into the area between the first air hole 24 and the second air hole 25 through the gap between the sealing ring assembly 3 and the borehole wall, the water pump 7 draws out the seeping clean water through the inlet pipe 71 and discharges it back to the return water gap 21 through the outlet pipe 72. This prevents water column accumulation that could prevent gas from escaping, maintaining a dynamic seal. Furthermore, an abnormally increased flow rate of the water pump 7 can serve as a sign that drilling has reached the unconfined depth layer.

[0040] Furthermore, a one-way valve 73 is connected to the outlet pipe 72, which only allows fluid to flow from the water pump 7 to the outlet pipe 72.

[0041] Specifically, such as Figure 2 , Figure 3 As shown, the one-way valve 73 prevents the slag-containing clean water in the return water gap 21 from flowing back into the water pump 7, thus avoiding wear or blockage of the impeller of the water pump 7 and extending its service life.

[0042] Furthermore, multiple water immersion sensors 74 are fixedly connected to the pump body of the water pump 7, and the water immersion sensors 74 are distributed along the vertical direction.

[0043] Specifically, such as Figure 6 As shown, four water immersion sensors 74 can be configured, distributed from top to bottom at different heights on the pump body, namely h1, h2, h3, and h4, to monitor the water level above the sealing ring assembly 3 in real time. When the water level rises to the h4 elevation, the micro water pump 7 starts and begins pumping water; the drainage levels h3, h2, and h1 increase sequentially, with h1 being the maximum drainage level of the water pump 7. The pumped water flow rate can be fed back to the ground control system through sensors such as electromagnetic flow meters.

[0044] Furthermore, it also includes a third sealing ring 8, a second vent 25 located between the third sealing ring 8 and the sealing ring group 3, and a water-stop rubber ring 81 sleeved on the outer wall of the third sealing ring 8. The water-stop rubber ring 81 is used to fit against the inner wall of the borehole to form a seal, and the water pressure gauge 4 is located above the water-stop rubber ring 81.

[0045] Specifically, such as Figure 1 , Figure 4 As shown, the third sealing ring 8 and the water-stop rubber ring 81 form a static seal on the borehole wall. Positioning the water pressure gauge 4 above the water-stop rubber ring 81 allows for precise measurement of the water column pressure formed after the submersible passes through the sealing ring assembly 3 and the third sealing ring 8, avoiding interference from the seepage of drilling water and improving the accuracy of initial water level detection. When drilling reaches the submersible layer, the electromagnetic flowmeter installed on the outlet pipe shows a sudden increase in flow rate, and the pressure sensed by the water pressure gauge 4 also increases sharply from zero. Based on the sudden increase in flow rate from the electromagnetic flowmeter and the sharp increase in pressure from the water pressure gauge 4, it can be determined that the submersible has reached its initial water level, and the drilling depth at this point can be recorded. Furthermore, the material of the water-stop rubber ring 81 is set to wear-resistant rubber.

[0046] Specifically, the rough and hard rock borehole walls cause ordinary rubber to wear down easily, leading to seal failure. Wear-resistant rubber can withstand friction during drilling, maintain a long-term sealing effect, and avoid frequent replacements.

[0047] The present invention also provides a method for measuring the initial diving visibility level. The method for measuring the initial diving visibility level using the device of the present invention includes the following steps: S1: Combination drill pipe 1 and measuring sleeve 2, installed on the drilling rig; Specifically, such as Figure 5 As shown, the combination of drill rod 1 and measuring casing 2 can be configured as a structure with multiple segments fixedly connected end to end. The water pressure gauge 4, water pump 7 and water immersion sensor 74 are connected to the ground control system through multiple segments of cable 9. Adjacent cables 9 are connected through plug 91 and socket 92. S11: Drilling fluid is introduced into the water inlet channel 11 of drill pipe 1, and air is introduced into the air inlet channel 22; S2: The pressure of air entering the air intake channel 22 is dynamically adjusted according to the instantaneous flow rate of the water pump 7 and the water level height, so that the high-pressure gas can just balance the pressure of the drilling fluid between the sealing ring group 3 and the borehole wall, so that the drilling fluid will not pass through the sealing ring group 3 and come into contact with the water pressure gauge 4, maintaining a "semi-dry and semi-wet" drilling state to ensure the integrity of water circulation.

[0048] S3: When drilling into the phreatic layer, the water pressure measured by the water pressure gauge 4 continues to increase with drilling, the water level of the water pump 7 continues to increase and the water flow rate increases abnormally. Specifically, after the drill bit 12 touches the top plate of the aquifer, a large amount of seepage water enters between the second sealing ring 32 and the third sealing ring 8 and comes into contact with the water pressure gauge 4. The water immersion sensor 74 is triggered step by step, the water pump 7 continuously drains water, and the electromagnetic flow meter shows a sudden increase in flow rate. The seepage water forms a stable water column at the water pressure gauge 4, and the pressure of the water pressure gauge 4 increases sharply from zero.

[0049] S4: The water column pressure of the hydraulic gauge 4 increases approximately linearly with drilling depth. By fitting the measurement points, a direct proportional function is obtained. The drilling depth at the initial non-zero pressure endpoint of the function is the initial water level encountered by the groundwater. Based on the number of drill pipes below drill pipe 1 and the depth of the equipment arrangement, using... The formula is used to deduce the depth of the diving layer.

[0050] Where there is no conflict, the above embodiments and features described herein can be combined with each other.

[0051] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A device for measuring the initial water level of a shallow-water borehole in rock formations, characterized in that: It includes a measuring sleeve and a water pressure gauge. The measuring sleeve is used for the drill rod to pass through, and a water return gap is provided between the outer wall of the drill rod and the inner wall of the measuring sleeve. A sealing ring assembly is connected to the outer wall of the measuring sleeve. The water pressure gauge is located above the sealing ring assembly. The sealing ring assembly includes a first sealing ring and a second sealing ring that are axially fitted onto the outer wall of the measuring sleeve. An axially extending air inlet channel and an air outlet channel are provided inside the tube wall of the measuring sleeve. A first air hole and a second air hole are opened on the measuring sleeve. The first air hole is located between the first sealing ring and the second sealing ring and is connected to the air inlet channel. The sealing ring assembly is located between the second air hole and the outlet of the measuring sleeve.

2. The diving initial water level measuring device according to claim 1, characterized in that: The measuring sleeve is covered with a first isolation net, which covers the first air hole.

3. The diving initial water level measuring device according to claim 2, characterized in that: A high-pressure air nozzle is connected to the first air hole, and the outlet of the high-pressure air nozzle faces the first isolation net.

4. The diving initial water level measuring device according to claim 1, characterized in that: The measuring sleeve is fitted with a second isolation net, which covers the second air hole.

5. The diving initial water level measuring device according to claim 1, characterized in that: It also includes a water pump, an inlet pipe, and an outlet pipe. The water pump is connected to the outside of the measuring sleeve through the inlet pipe. The end of the inlet pipe away from the water pump is located between the first air hole and the second air hole. The water pump is connected to the inside of the measuring sleeve through the outlet pipe. The water pump is used to transport water from the inlet pipe to the outlet pipe.

6. The diving initial water level measuring device according to claim 5, characterized in that: A one-way valve is connected to the outlet pipe, which only allows fluid to flow from the water pump to the outlet pipe.

7. The diving initial water level measuring device according to claim 5, characterized in that: Multiple water immersion sensors are fixedly connected to the pump body of the water pump, and the water immersion sensors are distributed along the vertical direction.

8. The diving initial water level measuring device according to claim 1, characterized in that: It also includes a third sealing ring, the second air hole is located between the third sealing ring and the sealing ring group, the outer wall of the third sealing ring is fitted with a water-stop rubber ring, the water-stop rubber ring is used to fit against the inner wall of the borehole to form a seal, and the water pressure gauge is located above the water-stop rubber ring.

9. The diving initial water level measuring device according to claim 8, characterized in that: The material of the water-stopping rubber ring is made of wear-resistant rubber.

10. A method for measuring initial water level during diving, applied to the initial water level measuring device according to any one of claims 1-9, characterized in that: Includes the following steps: S1: Combine the measuring sleeve with the drill pipe and install it on the drilling rig; S2: Pass drilling fluid into the water inlet channel of the drill pipe and air into the air inlet channel to balance the air pressure with the water pressure below the sealing ring assembly; S3: When drilling reaches the water-bearing layer, the pressure gauge detects a sudden change in pressure reading that continues to increase as drilling progresses, indicating that drilling has reached the water-bearing layer.

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