Water pressure test device not easy to wear

Abstract

The utility model discloses a water pressure test device not easy to wear, which comprises a drilling machine, and a drill rod of the drilling machine is forwards connected with a double-end plug water plugging device; the double-end plug water plugging device comprises an inner pipe, a rear water stopping plug and a front water stopping plug are installed on the inner pipe in a front-back spaced mode, the front water stopping plug comprises a front capsule, and the rear water stopping plug comprises a rear capsule. The inner pipe forwards extends out of the front water stop plug, backwards extends out of the rear water stop plug and is connected with a drill rod; the inner tube between the front capsule and the rear capsule is of a floral tube structure, and the floral tube structure is used for injecting water into the water pressure test section of the drill hole; a rear supporting structure used for supporting the rear end of the double-end plug water plugging device is arranged at the front end of the drill rod, and a front supporting structure used for supporting the front end of the double-end plug water plugging device is arranged at the front end of the inner pipe. The rear supporting structure and the front supporting structure are symmetrically arranged; the rear supporting structure and the front supporting structure are both connected with the hole wall of the drill hole in a pressing mode through rollers. The double-end embolism water plugging device is supported on the front side and the rear side through the front supporting structure and the rear supporting structure, the double-end embolism water plugging device, the front capsule and the rear capsule are suspended in a drill hole, when the double-end embolism water plugging device is pushed in or pulled out of the drill hole, the front capsule and the rear capsule do not make contact with the wall of the drill hole generally, and even if the front capsule and the rear capsule make contact with each other, contact stress is small; therefore, the abrasion of the capsule when the long drill hole is pushed forwards or pulled out is greatly reduced, the service life of the capsule is prolonged, and the test cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of borehole water pressure detection, in particular to a water pressure test technology capable of coping with long borehole plugging. Background Art

[0002] The water pressure test is a method used to evaluate the permeability and pressure conditions of rock formations. The water pressure test injects high-pressure water into the borehole to observe the penetration and diffusion of water, thereby understanding the permeability, stress state, and crack distribution of the coal seam or surrounding rock. This is of great significance to the safe production of coal mines and resource mining planning.

[0003] The following reasons may cause the borehole to become clogged:

[0004] 1. Rock cuttings deposition: The rock cuttings generated by the drill bit during the drilling process may be deposited in the borehole and become a cause of blockage.

[0005] 2. Mud intrusion: If mud is used to lubricate the drill bit and carry rock cuttings during drilling, solid particles in the mud may settle.

[0006] 3. Improper sealing. The borehole needs to be sealed before the water pressure test. Improper sealing may cause the borehole to be blocked.

[0007] 4. Cracks. Natural cracks or pores in the formation may be blocked by sediments brought in by pressure changes or water flow.

[0008] 5. Chemical reaction. The water injected during the water pressure test may react chemically with the minerals in the formation, generating precipitates and causing blockage. For example, calcium carbonate in the water reacts with sulfate in the formation to generate calcium sulfate and form precipitates.

[0009] 6. Microorganisms. Under suitable conditions, microorganisms in the formation may multiply in large numbers, producing biofilms or other organic matter that can clog the borehole.

[0010] 7. Swelling minerals: Some minerals, such as bentonite, swell when exposed to water, causing the borehole to become clogged.

[0011] 8. High-pressure water flushing: During the water pressure process, fine particles in the formation may be flushed away. These particles will settle in areas where the water flow slows down or stagnates, which may cause blockage.

[0012] When blockage occurs, the water flow in the borehole is blocked, water may not be able to enter the surrounding rock layer smoothly, and the double-ended water plug may not be smoothly pushed to the predetermined test depth by the drilling rig. Forcibly pushing the test equipment deep into the borehole when blockage occurs is also very likely to cause damage to the test equipment, especially the breakage of the sealing capsule. These will affect the normal progress of the water pressure test, and thus clearing operations are required.

[0013] The application scenario targeted by the utility model is mainly a long borehole water pressure test.

[0014] The length of a long borehole can reach 1,000 meters. In practice, long boreholes of 100 to 200 meters are more common.

[0015] When conducting a water pressure test on a long borehole, the following steps are usually followed:

[0016] 1. Drilling preparation. Select the location and depth of the drilling water pressure test, and clean the borehole to prevent debris in the borehole from affecting the test results.

[0017] 2. Seal the borehole. Use cement slurry, bentonite or other sealing materials to seal the borehole to prevent water from seeping or even leaking through the sealing section.

[0018] 3. Install water pressure test equipment.

[0019] 4. Carry out a water pressure test, gradually inject water into the borehole, or gradually increase the pressure (increase the injection pressure), or increase the injection pressure in steps, and observe the water penetration.

[0020] Record the test data (water injection pressure, flow rate, time, etc.) for later data analysis. Subsequent data analysis can be used to evaluate the surrounding rock permeability, calculate the surrounding rock permeability coefficient and pore pressure, understand the distribution and characteristics of cracks in the surrounding rock, etc., to provide support for coal mine safety production, resource mining planning, drilling utilization planning, etc.

[0021] For example, for coal mine safety production, water pressure test has the following significance:

[0022] The coal mining process will destroy the equilibrium state of the original rock stress field. The stress redistribution causes the overburden to move, deform and destroy, forming a roof damage zone. Under the action of the supporting pressure, the tensile stress and shear stress cause a series of fractures in the bottom plate that are perpendicular and parallel to the layer, forming a bottom plate damage zone, which makes the working face threatened by various types of water disasters such as surface water, old empty water, bottom plate pressure water, and roof water. In order to ensure the safe mining of coal seams, it is of great significance to study a borehole water injection test instrument to study the development law of water-conducting fracture zones and bottom plate damage zones.

[0023] The double-end water plug is the main equipment for underground borehole segmented water pressure observation, including an upper end plug (upper plugging capsule), a lower end plug (lower plugging capsule), connecting pipes, water injection pipes, pressure sensors and flow meters and other equipment. The drilling section between the upper end plug and the lower end plug forms a water pressure test section, or a target test section.

[0024] At present, double-end water plugging devices and other drilling water pressure test equipment have the problem that the plugging capsules are easily worn and damaged.

[0025] The reason for easy wear is that there is sliding friction between the capsule and the wall of the borehole, and usually the weight of the capsule is mostly supported by the front end of the capsule, and there is a large pressure between the front end of the capsule and the wall of the borehole. When the capsule is pushed forward relative to the wall of the borehole (to the predetermined test position), the capsule is easily worn due to sliding friction with the wall of the borehole. If there is a damage zone in the borehole, the capsule may be scratched by the broken borehole wall and the gravel in the borehole when passing through the damage zone in the borehole, resulting in sealing failure.

[0026] The problems of wear and breakage shorten the service life of the capsule, which is not conducive to the long-term and repeated participation of the capsule in the water pressure test. It may be necessary to replace the capsule for testing, which increases the cost of the test and reduces the test efficiency. Utility Model Content

[0027] The utility model aims to provide a water pressure test device which is not easy to wear, and solves the problem of wear and tear of the capsule by designing a structure in which the capsule is suspended in the process of advancing in the drilling hole.

[0028] To achieve the above-mentioned purpose, the utility model provides a water pressure test device that is not easy to wear, with the direction of drilling deep into the borehole as the forward direction and the radial direction of the borehole as the radial direction; it includes a drilling rig, the drill rod of the drilling rig is connected to a double-ended embolic water plug forward; the double-ended embolic water plug includes an inner tube, and a rear water stop plug and a front water stop plug are installed on the inner tube at intervals in front and back, the front water stop plug includes a front capsule, and the rear water stop plug includes a rear capsule; the inner tube extends forward from the front water stop plug, and the inner tube extends backward from the rear water stop plug and is connected to the drill rod; the inner tube between the front capsule and the rear capsule is a flower tube structure, and the flower tube structure is used to inject water into the water pressure test section of the borehole;

[0029] The front end of the drill pipe is provided with a rear support structure for supporting the rear end of the double-ended embolic water plug, and the front end of the inner tube is provided with a front support structure for supporting the front end of the double-ended embolic water plug;

[0030] The rear support structure and the front support structure are symmetrically arranged; the rear support structure and the front support structure are both pressed against the hole wall of the drilled hole through rollers.

[0031] The front support structure includes two sets of limiting structures arranged on the inner tube; the two sets of limiting structures are symmetrically arranged front and back, a wheel frame is connected between the two sets of limiting structures, and rollers are arranged on the wheel frame; two or three sets of wheel frames and rollers are evenly spaced along the circumference of the inner tube.

[0032] The direction pointing to the symmetry center of the two sets of limiting structures is regarded as the inward direction, and the direction pointing to the radial outside of the borehole is regarded as the outward direction;

[0033] The limiting structure includes a nut, which is threadedly connected to the inner tube, the nut is inwardly connected to a spring, the spring is inwardly connected to a moving plate, the moving plate is sleeved on the inner tube, the moving plate is connected to a hinged rod, and the hinged rod is hinged to the wheel frame in a one-to-one correspondence.

[0034] The wheel frame is triangular in shape, and rollers are respectively installed at the three vertices of the triangular wheel frame. The three rollers are sprockets, and crawler chains are wound around the three rollers. The crawler chains are used to press on the wall of the drilled hole.

[0035] The utility model has the following advantages:

[0036] The utility model has a simple structure. The double-ended embolic water plugger is supported at the front and rear sides of the double-ended embolic water plugger by a rear supporting structure and a front supporting structure, so that the double-ended embolic water plugger and the front capsule and the rear capsule of the double-ended embolic water plugger are suspended in the borehole. When the capsule is pushed forward or pulled out in the borehole, the front capsule and the rear capsule generally do not contact the borehole wall. Even if there is occasional contact, the contact force is very small, thereby greatly reducing the wear of the capsule when it is pushed forward or pulled out in a long borehole, extending the service life of the capsule and reducing the test cost.

[0037] The setting of the limit structure is simple. By changing the front and rear positions of the nut or replacing springs with different elastic forces, the preload force of the spring can be adjusted, and then the opening angle of the hinged rod can be adjusted, and finally the tightening pressure between the roller and the wall of the drilled hole can be adjusted to reduce the rolling friction as much as possible (the smaller the tightening pressure, the smaller the rolling friction) under the constraint of satisfying the support stability (the greater the tightening pressure, the more stable the support).

[0038] The crawler chain converts the tight rotational cooperation between the roller and the wall of the drilled hole into the tight rotational cooperation between the crawler chain and the wall of the drilled hole, which expands the force area, reduces the pressure on the wall of the drilled hole, is not easy to damage or change the wall structure of the drilled hole, is conducive to smooth advancement or extraction, and is conducive to the smooth progress of the test. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a structural schematic diagram of the utility model.

[0040] Figure 2 yes Figure 1 Enlarged view of point B in the middle.

[0041] Figure 3 yes Figure 2 Enlarged view of point A in the middle. DETAILED DESCRIPTION

[0042] like Figures 1 to 3As shown, the utility model provides a water pressure test device that is not easy to wear, with the direction of drilling deep into the borehole as the forward direction and the radial direction of the borehole as the radial direction; it includes a drilling rig 1, and the drill rod 7 of the drilling rig 1 is connected to a double-ended embolic water plug forward; the double-ended embolic water plug includes an inner tube 2, and a rear water stop plug 3 and a front water stop plug 4 are installed on the inner tube 2 at intervals in front and back, the front water stop plug 4 includes a front capsule 5, and the rear water stop plug 3 includes a rear capsule 6; the inner tube 2 extends the front water stop plug 4 forward, and the inner tube 2 extends the rear water stop plug 3 backward and is connected to the drill rod 7; the inner tube 2 between the front capsule 5 and the rear capsule 6 is a flower tube structure 8 (the flower tube structure 8 is that a plurality of radial through holes 15 are distributed on the tube wall of the inner tube 2), and the flower tube structure 8 is used to inject water into the water pressure test section of the borehole; the water stop plug and the plugging capsule are both existing technologies and are not described in detail.

[0043] The front end of the drill pipe 7 is provided with a rear support structure for supporting the rear end of the double-ended embolic water plug, and the front end of the inner tube 2 is provided with a front support structure for supporting the front end of the double-ended embolic water plug;

[0044] The rear support structure and the front support structure are symmetrically arranged; the rear support structure and the front support structure are both pressed against the hole wall of the drilled hole through rollers.

[0045] The utility model has a simple structure. The double-ended embolic water plugger is supported at the front and rear sides of the double-ended embolic water plugger by a rear supporting structure and a front supporting structure, so that the double-ended embolic water plugger and its front capsule 5 and rear capsule 6 are suspended in the borehole. When the double-ended embolic water plugger is pushed forward or pulled out in the borehole, the front capsule 5 and the rear capsule 6 generally do not contact the borehole wall. Even if there is occasional contact, the contact force is very small, thereby greatly reducing the wear of the capsule when it is pushed forward or pulled out in a long borehole, extending the service life of the capsule and reducing the test cost.

[0046] The front support structure includes two sets of limiting structures arranged on the inner tube 2; the two sets of limiting structures are arranged symmetrically front and back, a wheel frame 9 is connected between the two sets of limiting structures, and a roller 10 is arranged on the wheel frame 9; two or three sets of the wheel frame 9 and the roller 10 are evenly spaced along the circumference of the inner tube 2. The rear support structure is symmetrically arranged with the front support structure, so the structure of the rear support structure is not repeated.

[0047] The direction pointing to the symmetry center of the two sets of limiting structures is regarded as the inward direction, and the direction pointing to the radial outside of the borehole is regarded as the outward direction;

[0048] The limiting structure includes a nut 11, which is threadedly connected to the inner tube 2 (the outer surface of the inner tube 2 has threads; the nut 11 of the rear support structure is threadedly connected to the front end of the drill rod 7), the nut 11 is connected inwardly to a spring 12, the spring 12 is connected inwardly to a movable plate 13, the movable plate 13 is sleeved on the inner tube 2 (the movable plate 13 preferably has a clearance fit with the inner tube 2 to facilitate forward and backward sliding), the movable plate 13 is connected to a hinged rod 14, and the hinged rod 14 is hinged to the wheel frame 9 in a one-to-one correspondence.

[0049] The limiting structure is simple to set up. By changing the front and rear positions of the nut 11 or replacing the spring 12 with different elastic forces, the preload force of the spring 12 can be adjusted, and then the opening angle of the hinge rod 14 can be adjusted, and finally the tightening pressure between the roller 10 and the wall of the drilled hole can be adjusted to reduce the rolling friction as much as possible (the smaller the tightening pressure, the smaller the rolling friction) under the constraint of satisfying the support stability (the greater the tightening pressure, the more stable the support).

[0050] The wheel frame 9 is triangular in shape, and rollers 10 are respectively installed at the three vertices of the triangular wheel frame 9. The three rollers 10 are all sprockets. A crawler chain 15 is wound around the three rollers 10. The crawler chain 15 is used to press on the wall of the drilled hole.

[0051] The crawler chain 15 converts the tight rotational cooperation between the roller 10 and the wall of the drilled hole into the tight rotational cooperation between the crawler chain 15 and the wall of the drilled hole, which expands the force-bearing area, reduces the pressure on the wall of the drilled hole, is not easy to damage or change the wall structure of the drilled hole, is conducive to smooth advancement or extraction, and is conducive to the smooth progress of the test.

[0052] When in use, a water pressure test device that is not easy to wear is connected at the opening of the borehole, and the double-ended embolic water plug and the drill rod 7 are inserted into the borehole; the drilling rig 1 is started, and the double-ended embolic water plug and the drill rod 7 are pushed deep into the borehole. The goal of the push is to push the double-ended embolic water plug to the predetermined water pressure test position; during the push, the rear support structure and the front support structure support the double-ended embolic water plug to a suspended state, thereby protecting the capsule from being easily damaged. The crawler chain 15 has a much larger contact area with the borehole wall than the roller 10, which enhances the stability during movement.

[0053] The above embodiments are only used to illustrate rather than limit the technical solutions of the present invention. Although the present invention is described in detail with reference to the above embodiments, those skilled in the art should understand that the present invention can still be modified or replaced by equivalents. Any modification or partial replacement that does not depart from the spirit and scope of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A water pressure test device that is not easy to wear, with the direction of drilling deep into the borehole as the forward direction and the radial direction of the borehole as the radial direction; it includes a drilling rig, the drill rod of the drilling rig is connected to a double-ended embolic water plug forward; the double-ended embolic water plug includes an inner tube, and a rear water stop plug and a front water stop plug are installed on the inner tube at intervals in front and back, the front water stop plug includes a front capsule, and the rear water stop plug includes a rear capsule; the inner tube extends forward from the front water stop plug, and the inner tube extends backward from the rear water stop plug and is connected to the drill rod; the inner tube between the front capsule and the rear capsule is a flower tube structure, and the flower tube structure is used to inject water into the water pressure test section of the borehole; Features: The front end of the drill pipe is provided with a rear support structure for supporting the rear end of the double-end embolic water plug, and the front end of the inner tube is provided with a front support structure for supporting the front end of the double-end embolic water plug; The rear support structure and the front support structure are symmetrically arranged; the rear support structure and the front support structure are both pressed against the hole wall of the drilled hole through rollers.

2. The wear-resistant water pressure testing device according to claim 1, characterized in that: The front support structure includes two sets of limiting structures arranged on the inner tube; the two sets of limiting structures are symmetrically arranged front and back, a wheel frame is connected between the two sets of limiting structures, and rollers are arranged on the wheel frame; two or three sets of wheel frames and rollers are evenly spaced along the circumference of the inner tube.

3. The wear-resistant water pressure testing device according to claim 2, characterized in that: The direction pointing to the symmetry center of the two sets of limiting structures is regarded as the inward direction, and the direction pointing to the radial outside of the borehole is regarded as the outward direction; The limiting structure includes a nut, which is threadedly connected to the inner tube, the nut is inwardly connected to a spring, the spring is inwardly connected to a moving plate, the moving plate is sleeved on the inner tube, the moving plate is connected to a hinged rod, and the hinged rod is hinged to the wheel frame in a one-to-one correspondence.

4. The wear-resistant water pressure testing device according to claim 3, characterized in that: The wheel frame is triangular in shape, and rollers are respectively installed at the three vertices of the triangular wheel frame. The three rollers are sprockets, and crawler chains are wound around the three rollers. The crawler chains are used to press on the wall of the drilled hole.

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