A hydrological observation hole construction process and hydrological observation hole casing

Abstract

The present invention is a hydrological observation hole construction process and a hydrological observation hole casing, which belongs to the field of coal mine hydrological monitoring technology. Its technical solution is to drill overflow holes on the top of the primary and secondary casings, and discharge the internal construction water when injecting the coagulant to avoid dilution of the coagulant. After solidification, there is no water accumulation inside, making the observation hole structure more stable. The beneficial effects of the present invention are that an overflow hole is drilled on the outer casing, and the internal construction water is discharged through the overflow hole when injecting the coagulant, avoiding dilution of the coagulant by water and corrosion caused by internal water accumulation; at the same time, it is convenient to observe the injection status, and can ensure complete grouting, the observation hole structure is more stable, the life of the observation hole is increased, and the progress of coal mining is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of coal mine hydrological monitoring, in particular to a hydrological observation hole construction process and a hydrological observation hole casing. Background Art

[0002] During coal mining construction, groundwater is an important factor affecting the quality and safety of coal mining construction, especially Ordovician ash water, which accounts for the majority of groundwater. Drainage and pressure reduction is the main solution for Ordovician ash water management. The standard for drainage and pressure reduction is to analyze and evaluate the water pressure of the hydrological observation hole. The construction drilling is used to drain the Ordovician ash water and reduce the Ordovician ash water pressure on the bottom plate of the working face. Due to the influence of mine pressure and mining, the hydrological observation hole has a pressure relief phenomenon. Once the observation hole is depressurized, the water pressure cannot be observed, the water volume cannot be controlled, and the bottom plate is damaged. The observation hole cannot be remedied after the pressure relief. It is also difficult to find another suitable observation site due to the influence of the underground site and geological conditions.

[0003] At present, hydrological observation holes usually adopt a three-level nesting and layer-by-layer method to lower the casing. After the second and third layers of casing are lowered, cement needs to be injected into the casing interlayer for reinforcement. Since the top ends of the casing are fixed to each other by flanges, the construction water in the interlayer cannot be removed when the cement is injected, resulting in cement dilution and cement sedimentation. The settled water remains in the casing interlayer and cannot be discharged, which will corrode the casing over time and affect the life of the observation hole. Summary of the invention

[0004] Aiming at the problem that the current hydrological observation holes have a short service life and affect coal mining, the present invention provides a hydrological observation hole construction process for increasing the service life of the observation holes.

[0005] In order to solve the above problems, the technical solution adopted by the present invention is a hydrological observation hole construction process, including nesting and installing a primary casing, a secondary casing and a tertiary casing in sequence from the outside to the inside, and the casing installation adopts the following steps:

[0006] S1. Drilling a first pipe hole in the orifice bottom plate and the geological layer, inserting the lower portion of the primary casing into the first pipe hole;

[0007] S2. Inject a coagulant into the primary casing, so that the coagulant flows back to between the first tube hole and the outer wall of the primary casing at the bottom end of the primary casing;

[0008] S3. Drill a primary overflow hole at the top of the primary casing wall;

[0009] S4. Drill a second pipe hole in the primary casing and the geological layer, insert a secondary casing into the second pipe hole, and drill a secondary overflow hole at a position of the secondary casing corresponding to the primary overflow hole;

[0010] S5. Insert a plugging member into the primary overflow hole, the plugging member plugs the secondary overflow hole, and the diameter of the plugging member is smaller than the aperture of the primary overflow hole;

[0011] S6. Secondary grouting: injecting a coagulant into the secondary casing, causing the coagulant to flow back to between the second pipe hole and the outer wall of the secondary casing at the bottom of the secondary casing, and stopping the injection when the coagulant overflows from the primary overflow hole;

[0012] S7. Remove the blocking parts;

[0013] S8. Drilling a third borehole in the secondary casing and the geological layer, and inserting the tertiary casing into the third borehole;

[0014] S9. Tertiary grouting: injecting a coagulant into the tertiary casing, causing the coagulant to flow back from the bottom of the tertiary casing to between the third pipe hole and the outer wall of the tertiary casing, and stopping the injection when the coagulant overflows from the primary overflow hole;

[0015] S10. Drill observation holes in the tertiary casing and geological formations.

[0016] When using this construction process, overflow holes are drilled on the outer casing. When injecting the coagulant, the internal construction water is discharged through the overflow holes to prevent the coagulant from being diluted by water and to avoid internal water corrosion. At the same time, it is easy to observe the injection status, which can ensure that the grouting is complete, the observation hole structure is more stable, the life of the observation hole is increased, and the progress of coal mining is guaranteed.

[0017] Preferably, the primary overflow hole includes a first primary overflow hole and a second primary overflow hole, and the first primary overflow hole and the second primary overflow hole are arranged at intervals of 180° along the circumference of the primary casing; the secondary overflow hole includes a first secondary overflow hole and a second secondary overflow hole, and the first secondary overflow hole and the second secondary overflow hole are arranged at intervals of 180° along the circumference of the secondary casing. Drainage in two directions improves the drainage effect.

[0018] Preferably, step S6 further includes: after stopping the injection of the coagulant for a certain period of time, injecting the coagulant into the first-level overflow hole again, and stopping the injection when the coagulant overflows from the second-level overflow hole; step S9 further includes: after stopping the injection of the coagulant for a certain period of time, injecting the coagulant into the first-level overflow hole again, and stopping the injection when the coagulant overflows from the second-level overflow hole. After the cement settles, grouting is performed again through the overflow hole to discharge the upper layer of settled water, increase the internal cement concentration, and further improve the stability of the observation hole structure.

[0019] Preferably, in step S4, a nut is fixedly mounted on the outer wall of the secondary casing, the nut corresponds to the position of the second overflow hole, and the plugging member is a screw, the screw thread matches the nut, so as to facilitate disassembly and assembly, and form an overflow channel between the primary and secondary overflow holes.

[0020] Preferably, step S10 further includes: blocking the primary overflow hole, or blocking the primary overflow hole and the secondary overflow hole, to ensure the integrity of the observation hole structure.

[0021] Preferably, step S3 further comprises: installing a quick connector in the primary overflow hole, wherein the inner diameter of the quick connector is larger than the diameter of the plugging member; in step S10, installing a high-pressure shut-off valve on the quick connector to plug the primary overflow hole.

[0022] Preferably, the method further comprises: after the pressure of the completed hydrological observation hole is relieved, a grouting hole is drilled on the wall of the third-level casing through the first-level overflow hole and the second-level overflow hole, and a solidifying agent is injected into the observation hole to seal the observation hole. When the pressure of the observation hole is relieved, timely remediation is possible, and the operation is simple.

[0023] Preferably, the solidifying agent is cement or concrete.

[0024] On the other hand, the present invention also provides a hydrological observation hole casing, including a primary casing, a secondary casing and a tertiary casing nested in sequence from the inside to the outside, the inner diameter of the primary casing is larger than the outer diameter of the secondary casing, the inner diameter of the secondary casing is larger than the outer diameter of the tertiary casing, and the tops of the primary casing, the secondary casing and the tertiary casing are fixedly connected; a quick connector is provided at the upper end of the outer wall of the primary casing, the quick connector is connected to the interior of the primary casing, and a high-pressure gate is installed on the quick connector; a second overflow hole is provided on the wall of the secondary casing corresponding to the position of the quick connector, and a nut is provided at the second overflow hole. Among them, the length of the primary casing is 20m, the length of the secondary casing is 60m, and the length of the tertiary casing is 80m. The observation hole casing is easy to construct, the structure is stable and durable, the observation hole has a long service life, and the coal mining progress is guaranteed.

[0025] It can be seen from the above technical scheme that the advantages of the present invention are that, during the construction process, an overflow hole is drilled on the outer casing, and the internal construction water is discharged through the overflow hole when the coagulant is injected, so as to avoid dilution of the coagulant by water and corrosion caused by internal water accumulation; at the same time, it is convenient to observe the injection status, and can ensure that the grouting is complete, and the structure of the observation hole is more stable; after the cement is settled, grouting is performed again through the overflow hole to discharge the upper settled water, increase the internal cement concentration, further improve the stability of the observation hole structure, and increase the life of the observation hole; it can be sealed in time after the pressure relief of the observation hole fails; at the same time, the casing of the observation hole is easy to construct, the structure is stable and durable, the service life of the observation hole is long, and the progress of coal mining is guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solution of the present invention, the accompanying drawings required for use in the description will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0027] Figure 1 It is a schematic diagram of the structure of the hydrological observation hole after one grouting in a specific implementation manner of the present invention.

[0028] Figure 2 It is a schematic diagram of the structure of the hydrological observation hole after secondary grouting in a specific implementation manner of the present invention.

[0029] Figure 3 It is a schematic diagram of the structure of the hydrological observation hole after construction is completed in a specific implementation manner of the present invention.

[0030] Figure 4 It is a schematic diagram of the structure of the hydrological observation hole casing in a specific implementation manner of the present invention.

[0031] In the figure: 1. primary casing, 2. secondary casing, 3. tertiary casing, 4. nut, 5. quick connector, 6. high pressure valve, 7. orifice bottom plate, 8. coagulant, 9. geological layer, 10. screw. DETAILED DESCRIPTION

[0032] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical scheme of the present invention will be clearly and completely described below in conjunction with the drawings in this specific embodiment. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of them. Based on the embodiments in this patent, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this patent.

[0033] like Figure 1-3 As shown, a hydrological observation hole construction process includes sequentially nesting and installing a primary casing 1, a secondary casing 2, and a tertiary casing 3 from the outside to the inside, including the following steps:

[0034] S1. Drill a first pipe hole in the orifice bottom plate 7 and the geological layer 9, and insert the lower portion of the primary casing 1 into the first pipe hole;

[0035] S2. Primary grouting: injecting a coagulant 8 into the primary casing 1, the coagulant may be cement or concrete, so that the coagulant flows back to between the first pipe hole and the outer wall of the primary casing 1 at the bottom of the primary casing 1, and after the coagulant of the primary grouting solidifies, the primary casing 1 is fixed in the geological layer 9;

[0036] S3. Drill two primary overflow holes at the top of the primary casing 1 wall. The first primary overflow hole and the second primary overflow hole are arranged 180° apart along the circumference of the primary casing 1, and a quick connector 5 is installed in the primary overflow hole. At this time, the observation hole structure is as follows: Figure 1 As shown;

[0037] S4. Drill a second pipe hole in the primary casing 1 and the geological layer 9, remove the coagulant remaining in the primary casing 1 during the first grouting, and continue to drill the secondary casing into the geological layer 9 to the required depth, insert the secondary casing 2 into the second pipe hole, and drill a secondary overflow hole at a position of the secondary casing 2 corresponding to the primary overflow hole, the first secondary overflow hole and the second secondary overflow hole, and the first secondary overflow hole and the second secondary overflow hole are arranged at an interval of 180° along the circumference of the secondary casing 2;

[0038] S5. Insert a plugging member into the primary overflow hole, the plugging member plugs the secondary overflow hole, and the diameter of the plugging member is smaller than the aperture of the primary overflow hole;

[0039] S6. Secondary grouting: inject a coagulant into the secondary casing 2, so that the coagulant flows back to the second tube hole and the outer wall of the secondary casing 2 at the bottom of the secondary casing 2. During the grouting process, the coagulant drives the construction water in the second tube hole out of the primary overflow hole. When the coagulant overflows the primary overflow hole, the injection is stopped. After a certain period of time, the injected coagulant settles and a small amount of precipitated water is generated in the upper layer. At this time, the coagulant is injected into the first-level overflow hole again, and the precipitated water is discharged from the second-level overflow hole. When the coagulant overflows from the second-level overflow hole, the injection is stopped. At this time, the hole structure is observed as follows: Figure 2 As shown;

[0040] S7. After the plugging member is removed and the secondary grouting solidifies, the secondary casing 2 is fixed in the geological layer 9, and an overflow channel is formed between the first overflow hole and the second overflow hole after the plugging member is removed;

[0041] S8. Drill a third borehole in the secondary casing 2 and the geological layer 9, remove the residual coagulant inside the secondary casing 2 after the secondary grouting, and drill the tertiary casing to the required depth in the geological layer 9, insert the tertiary casing 3 into the third borehole;

[0042] S9. Three groutings: inject a coagulant into the tertiary casing 3, so that the coagulant flows back to the third tube hole and the outer wall of the tertiary casing 3 at the bottom end of the tertiary casing 3. During the grouting process, the coagulant drives out the construction water in the third tube hole from the overflow channel between the primary and secondary overflow holes. When the coagulant overflows from the primary overflow hole, the injection is stopped. After a certain period of time, the coagulant settles and a small amount of precipitated water is generated in the upper layer. At this time, the coagulant is injected into the first-level overflow hole again. The coagulant enters the third tube hole through the overflow channel and drives out the precipitated water from the second-level overflow hole. When the coagulant overflows from the second-level overflow hole, the injection is stopped;

[0043] S10. Drill an observation hole in the tertiary casing 3 and the geological layer 9, install a high-pressure cut-off valve 6 on the quick connector 5, and block the primary overflow hole and the secondary overflow hole. The structure of the observation hole after the construction is completed is as follows: Figure 3 shown.

[0044] Among them, a nut 4 is fixedly installed on the outer wall of the secondary casing, and the nut 4 corresponds to the position of the second overflow hole; the blocking member is a screw rod 10, and the thread of the screw rod 10 matches with the nut 4.

[0045] When pressure relief occurs in the hydrological observation hole, the high-pressure shut-off valve can be removed, holes can be drilled at the locations of the first-level overflow hole and the second-level overflow hole, the wall of the third-level casing can be penetrated, and a coagulant can be injected into the observation hole to seal the observation hole.

[0046] Based on the above construction process, the present invention also provides a hydrological observation hole casing, such as Figure 4 As shown, it includes a primary casing 1, a secondary casing 2 and a tertiary casing 3 which are nested in sequence from the inside to the outside, the inner diameter of the primary casing 1 is larger than the outer diameter of the secondary casing 2, the inner diameter of the secondary casing 2 is larger than the outer diameter of the tertiary casing 3, and flanges are respectively provided at the tops of the primary casing 1, the secondary casing 2 and the tertiary casing 3, and the three flanges are stacked up and down and fixedly connected; a quick connector 5 is provided at the upper end of the outer wall of the primary casing 1, the quick connector 5 is connected to the interior of the primary casing 1, and a high-pressure shut-off valve 6 is installed on the quick connector 5; a second overflow hole is provided at the position of the pipe wall of the secondary casing 2 corresponding to the quick connector 5, and a nut 4 is provided at the second overflow hole.

[0047] Among them, the length of the primary casing 1 is 20m, the length of the secondary casing 2 is 60m, and the length of the tertiary casing 3 is 80m.

[0048] It can be seen from the above embodiments that the beneficial effects of the present invention are as follows: during the construction process, an overflow hole is drilled on the outer casing, and the internal construction water is discharged through the overflow hole when the coagulant is injected, so as to avoid dilution of the coagulant by water and corrosion caused by internal water accumulation; at the same time, it is convenient to observe the injection status, and the grouting can be ensured to be complete, and the structure of the observation hole is more stable; after the cement is settled, grouting is performed again through the overflow hole to discharge the upper settled water, thereby increasing the internal cement concentration, further improving the stability of the observation hole structure, and increasing the life of the observation hole; the observation hole can be sealed in time after the pressure relief fails; at the same time, the observation hole casing is easy to construct, the structure is stable and durable, the observation hole has a long service life, and the progress of coal mining is guaranteed.

[0049] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A hydrological observation hole construction process, comprising sequentially nesting and installing a primary casing (1), a secondary casing (2) and a tertiary casing (3) from the outside to the inside, characterized in that: The following steps are involved: S1. Drilling a first pipe hole in the orifice bottom plate (7) and the geological layer, inserting the lower portion of the primary casing (1) into the first pipe hole; S2. Primary grouting: injecting a solidifying agent into the primary casing (1), so that the solidifying agent flows back at the bottom of the primary casing (1) to between the first pipe hole and the outer wall of the primary casing (1); S3. Drilling a primary overflow hole at the top of the primary casing (1) wall; S4. Drilling a second pipe hole in the primary casing (1) and the geological layer, inserting the secondary casing (2) into the second pipe hole, and drilling a secondary overflow hole at a position of the secondary casing (2) corresponding to the primary overflow hole; S5. Install a plugging member in the primary overflow hole, wherein the diameter of the plugging member is smaller than the aperture of the primary overflow hole, and the plugging member blocks the secondary overflow hole; S6. Secondary grouting: injecting a solidifying agent into the secondary casing (2), causing the solidifying agent to flow back from the bottom end of the secondary casing (2) to between the second tube hole and the outer wall of the secondary casing (2), and stopping the injection when the solidifying agent overflows from the primary overflow hole; S7. Remove the blocking parts; S8. Drilling a third borehole in the secondary casing (2) and the geological layer, and inserting the tertiary casing (3) into the third borehole; S9. Three grouting: injecting a solidifying agent into the tertiary casing (3), so that the solidifying agent flows back to between the third tube hole and the outer wall of the tertiary casing (3) at the bottom end of the tertiary casing (3), and stopping the injection when the solidifying agent overflows from the primary overflow hole; S10. Drill observation holes in the tertiary casing (3) and the geological layer.

2. The hydrological observation hole construction process according to claim 1, characterized in that: The primary overflow hole comprises a first primary overflow hole and a second primary overflow hole, and the first primary overflow hole and the second primary overflow hole are arranged at an interval of 180° along the circumference of the primary casing (1); The secondary overflow hole comprises a first secondary overflow hole and a second secondary overflow hole, and the first secondary overflow hole and the second secondary overflow hole are arranged at an interval of 180° along the circumference of the secondary casing (2).

3. The hydrological observation hole construction process according to claim 2 is characterized in that: Step S6 also includes: after stopping the injection of the coagulant for a certain period of time, injecting the coagulant into the first-level overflow hole again, and stopping the injection when the coagulant overflows from the second-level overflow hole; Step S9 also includes: after stopping the injection of the coagulant for a certain period of time, injecting the coagulant into the first-level overflow hole again, and stopping the injection when the coagulant overflows from the second-level overflow hole.

4. The hydrological observation hole construction process according to any one of claims 1 to 3, characterized in that: In step S4, a nut (4) is fixedly mounted on the outer wall of the secondary casing, the nut (4) corresponding to the position of the secondary overflow hole; the blocking member is a screw, the screw thread matches the nut (4).

5. The hydrological observation hole construction process according to any one of claims 1 to 3, characterized in that: Step S10 also includes: blocking the primary overflow hole, or blocking the primary overflow hole and the secondary overflow hole.

6. The hydrological observation hole construction process according to claim 5, characterized in that: Step S3 further comprises: installing a quick connector (5) in the primary overflow hole, wherein the inner diameter of the quick connector (5) is greater than the diameter of the blocking member; In step S10, a high-pressure shut-off valve (6) is installed on the quick connector (5) to seal the primary overflow hole.

7. The hydrological observation hole construction process according to any one of claims 1 to 3, characterized in that: Also includes: When the completed hydrological observation hole is depressurized, grouting holes are drilled on the wall of the tertiary casing through the primary overflow hole and the secondary overflow hole, and a solidifying agent is injected into the observation hole to seal the observation hole.

8. The hydrological observation hole construction process according to any one of claims 1 to 3, characterized in that: The solidifying agent is cement or concrete.

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