A drilling broken zone magnetic suction type grouting device and method

Abstract

This invention discloses a magnetic grouting device and method for borehole fracturing, comprising a cylinder, a magnetic float valve structure, and a rope magnetic control system. The cylinder includes a tubular outer shell, a lifting ring structure at the top of the outer shell, and a double-cone structure at the bottom of the outer shell. The double-cone structure includes an inlet cone and an outlet cone, both of which are conical shell structures, connected at their smallest diameter ends. The magnetic float valve structure includes a ferromagnetic float and magnetic strips circumferentially arranged at the smallest diameter end of the inlet cone. The float, under the magnetic attraction of the magnetic strips and gravity, is confined within the inlet cone, sealing its smallest diameter end. The rope magnetic control system includes a rope and a magnetic chuck fixed to one end of the rope. The rope passes through the lifting ring structure, suspending the magnetic chuck below it. Lowering the rope causes the magnetic chuck to attract the float, thus releasing the float from blocking the smallest diameter end of the inlet cone. This invention enables lightweight and efficient small-scale borehole grouting operations with a borehole depth of up to 300m.

Description

Technical Field

[0001] This invention relates to the field of engineering geological exploration technology, and in particular to a magnetic grouting device and method for borehole fracture zones. Background Technology

[0002] In engineering geological exploration drilling, encountering fractured zones during conventional drilling can easily lead to borehole collapse and other accidents, affecting the accuracy of subsequent hydrogeological tests. For shallow holes, casing drilling is necessary to prevent borehole wall collapse; for deep holes, consolidation grouting is typically used to treat the fractured zones. Furthermore, during borehole water pressure testing, pre-consolidation grouting is also required for the fractured zones to form a relatively complete water-stopping plug. Traditional borehole consolidation grouting methods use specialized grouting equipment to inject grout into the rock fractures through a borehole guide pipe.

[0003] The disadvantages of specialized grouting equipment are as follows: First, specialized grouting equipment is usually large and heavy, and in complex terrain environments such as mountainous areas, transporting and installing this equipment will consume a lot of manpower and resources; second, for small-scale grouting operations in borehole pressure tests, the use of large equipment is inefficient and costly; third, when the hole depth is greater than 100m, traditional equipment is difficult to carry out grouting operations. Summary of the Invention

[0004] In view of this, the present invention provides a drilling and fracturing magnetic grouting device and method, which can realize lightweight and efficient small-scale drilling and grouting operations within a hole depth of 300m.

[0005] This invention is achieved through the following technical solution: a drilling and crushing magnetic grouting device, comprising: a cylinder, including a tubular outer shell, a lifting ring structure disposed at the top of the outer shell, and a double-cone structure disposed at the bottom of the outer shell, wherein the double-cone structure includes an inlet cone and an outlet cone, both of which are conical shell structures, with their small diameter ends connected to each other, and grout flowing from the large diameter end of the inlet cone into the double-cone structure and flowing out from the large diameter end of the outlet cone; a magnetic float valve structure, including a float made of ferromagnetic material and a magnetic strip arranged circumferentially at the small diameter end of the inlet cone; the float is confined within the inlet cone and blocks the small diameter end of the inlet cone under the magnetic attraction force of the magnetic strip and gravity; a rope magnetic control system, including a rope and a magnetic suction cup fixed to one end of the rope, the rope passing through the lifting ring structure to suspend the magnetic suction cup below the lifting ring structure, and the rope being lowered so that the magnetic suction cup attracts the float, thereby releasing the blockage of the small diameter end of the inlet cone by the float.

[0006] Furthermore, the magnetic float valve structure also includes a buffer washer, which is circumferentially arranged on the inner wall of the small diameter end of the inlet cone, and the magnetic strip is disposed inside the buffer washer.

[0007] Furthermore, the lifting ring structure includes a lifting ring body suspended above the outer shell and two or more fixing claws. The top ends of the fixing claws are evenly connected to the lifting ring body, and the bottom ends of the fixing claws are fixedly connected to the outer shell by fasteners.

[0008] Furthermore, the rope magnetic control system also has a fixing structure, which includes a counterweight ball and a connector. The diameter of the counterweight ball is larger than the diameter of the lifting ring body and smaller than the inner diameter of the outer shell. The bottom end of the rope passes through the inside of the counterweight ball, and the counterweight ball is fixedly connected to the middle of the magnetic chuck through the connector.

[0009] Furthermore, the cone angle of the inlet cone is 20°-23°, and the cone angle of the outlet cone is 10°-15°.

[0010] A magnetic grouting method for borehole fracture, employing the aforementioned magnetic grouting device, includes the following steps: Step 1: Placing a float inside the inlet cone, the float, under gravity and the magnetic attraction of the annular magnetic strip, seals the small-diameter end of the inlet cone; Step 2: Injecting grout from the top of the cylinder, the grout is stored in the space above the point where the inlet cone and float abut; Step 3: Tightening the rope to confine the counterweight ball and magnetic suction cup to the bottom of the lifting ring body; lowering the rope to place the cylinder at the bottom of the borehole; Step 4: Continuing to lower the rope, the magnetic suction cup falls into the inlet cone, attracting the float ball, and then the rope is pulled back upwards until the counterweight ball abuts the bottom of the lifting ring body, thereby releasing the magnetic float from sealing the small-diameter end of the inlet cone, the grout flows into the outlet cone and out from the bottom of the cylinder, and the cylinder is lifted out of the borehole.

[0011] Furthermore, the slurry is a high-strength, early-setting cement slurry with a water-cement ratio of 0.8:1 to 1:1.

[0012] Furthermore, step four involves two stages in which the cylinder 1 is lifted out of the borehole: in the first stage, during the slurry flow, the rope is steadily pulled upward to continuously and slowly lift the cylinder from the bottom of the borehole; in the second stage, after all the slurry has flowed out, the cylinder is lifted out of the borehole.

[0013] Compared with existing technologies, the beneficial effects of this invention are:

[0014] 1. This invention integrates a lifting ring structure and a double-cone structure in the cylinder body. Through the cooperation of a magnetic float valve and a rope magnetic control system, it can control whether the float blocks the small-diameter end of the double-cone inlet cone, thereby controlling whether the grout can be discharged. This device does not require pressurization and can grout from bottom to top inside the borehole. It is suitable for grouting operations in any complex terrain, and is simple and efficient. Depending on the rope length, under the requirements of standard operation, it can be used for small-to-medium-volume grouting operations in small-diameter borehole projects with a depth of up to 300m, for consolidation of fractured zones or water pressure test stop plug sections.

[0015] 2. The inlet cone of the present invention has a cone angle of 20°-23° and the outlet cone has a cone angle of 10°-15°, which can effectively reduce the flow resistance of slurry and prevent blockage; it can also increase the discharge speed of slurry and shorten the grouting time.

[0016] 3. The present invention has an annular buffer washer on the inner wall of the small diameter end of the inlet cone. After the slurry is injected into the cylinder, it compresses the float ball and the annular buffer washer to make tight contact, further ensuring the airtightness of the seal.

[0017] 4. The lifting ring structure of this invention, in conjunction with the rope magnetic control system, can lower the cylinder into or lift it from the borehole without the need for external equipment. At the same time, it can lower and retract the magnetic chuck, thereby attracting the float to release the blockage of the small diameter end of the inlet cone. The operation is simple, the weight is light, and it can effectively save time and manpower. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0019] Figure 2 This is a schematic diagram of the double-cone structure of the present invention.

[0020] Figure 3 This is a schematic diagram of the magnetic float valve structure of the present invention.

[0021] Figure 4 This is a schematic diagram of the rope magnetic control system of the present invention.

[0022] Among them, 1-cylinder body, 2-magnetic float valve structure, 3-rope magnetic control system, 101-outer shell, 102-double cone structure, 103-lifting ring body, 104-fixing claw, 105-M6 stainless steel bolt, 201-float, 202-ring rubber washer, 203-ring soft magnetic strip, 301-rope, 302-counterweight ball, 303-outer cover, 304-screw, 305-magnetic chuck, 306-ring rubber ring. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0024] The present invention provides a drilling and crushing device with magnetic grouting, which is suitable for small diameter boreholes of 75-150mm. The device includes a cylinder 1, a magnetic float valve structure 2, and a rope magnetic control system 3.

[0025] The cylinder 1 includes an outer shell 101, a lifting ring structure, and a double-cone structure 102. The outer shell 101 is a hollow tubular structure open at both ends. The outer diameter of the outer shell 101 is 10-20mm smaller than the borehole diameter. The length of the outer shell 101 is determined according to the specific construction conditions, generally 1m ± 0.2m. For shallow grouting applications, such as borehole depths below 100m, the outer shell 101 can be made of PVC material; for deep, high-pressure, and complex geological environments, such as borehole depths above 100m, the outer shell 101 can be made of 304 stainless steel. The outer shell 101 has a lifting ring structure at the top and a double-cone structure 102 at the bottom.

[0026] The lifting ring structure includes a lifting ring body 103 suspended above the outer casing 101 and two or more fixing claws 104. The top ends of the fixing claws 104 are evenly connected to the lifting ring body 103, and the bottom ends of the fixing claws 104 are fixedly connected to the outer casing 101 by fasteners. In this embodiment, the lifting ring structure is a triangular claw load-bearing lifting ring with three evenly distributed fixing claws 104. The top ends of the fixing claws 104 are fixed to the lifting ring body 103, and the other ends of the fixing claws 104 are fixedly installed on the top of the outer casing 101 by M6 stainless steel bolts 105. Both the fixing claws 104 and the lifting ring body 103 are made of 304 non-magnetic stainless steel.

[0027] The double cone structure 102 is open at both ends and hollow. The double cone structure 102 includes an inlet cone and an outlet cone, both of which are cone-shaped shell structures. The small diameter ends of the inlet cone and the outlet cone are connected to each other. The slurry flows into the double cone structure 102 from the large diameter end of the inlet cone and flows out from the large diameter end of the outlet cone.

[0028] In this embodiment, the double-cone structure 102 adopts a Venturi effect double cone, with a hollow cylindrical throat between the inlet cone and outlet cone, forming a contraction-expansion slurry flow channel. When the slurry enters the Venturi effect double cone, the inlet cone is the contraction section, where the flow channel cross-section gradually decreases, increasing the slurry velocity and decreasing the pressure; the throat is the narrow section, where the flow channel cross-section is the smallest, resulting in the maximum slurry velocity and the lowest pressure; the outlet cone is the expansion section, where the flow channel cross-section gradually expands, decreasing the slurry velocity and increasing the pressure. The Venturi effect double cone can reduce slurry flow resistance, prevent blockage, increase slurry discharge speed, and shorten grouting time.

[0029] If the inlet cone angle is too large, the slurry is prone to forming eddies, increasing energy loss. If the inlet cone angle is too small, the slurry flow path will be too long, affecting efficiency. A larger outlet cone angle can rapidly diffuse the slurry and reduce outlet back pressure, but an excessively large outlet cone angle may cause slurry separation. The cone angle refers to the angle between the generatrix of the cone and the axis of the cone. Preferably, the inlet cone angle is 20°-23° and the outlet cone angle is 10°-15° to ensure that the slurry can flow out smoothly and rapidly. In addition, the distance between the large-diameter end of the outlet cone and the bottom end of the outer shell 101 is 5-10cm, which can ensure the smooth flow of slurry from the outer shell 101 and reduce the occurrence of damage to the large-diameter end of the outlet cone.

[0030] The magnetic float valve structure 2 includes a float 201 and a magnetic strip circumferentially arranged at the small diameter end of the inlet cone. The magnetic strip can be an annular soft magnetic strip 203, used to attract the float 201. Under the magnetic attraction of the magnetic strip and gravity, the float 201 is confined within the inlet cone, sealing the small diameter end of the inlet cone. In a specific implementation, the magnetic float valve structure 2 also includes a buffer washer circumferentially arranged on the inner wall of the small diameter end of the inlet cone. The buffer washer can be an annular rubber ring 202, and the magnetic strip is located inside the annular rubber ring 202.

[0031] In this embodiment, the float 201 is a hollow iron sphere that can be attracted by a ring-shaped magnetic strip. Its diameter is not less than 1.2 times the inner diameter of the small diameter end of the inlet cone and not more than 0.5 times the inner diameter of the large diameter end of the inlet cone, with a wall thickness of 0.5 mm. Due to the shape of the inlet cone itself and the gravity of the float 201, the float 201 can seal the small diameter end of the inlet cone without the action of other external forces. Therefore, the magnetic force of the magnetic strip does not need to be too large, such as not less than 10 N, to ensure that the float 201 can be attracted and prevented from being washed away during the grouting of the double cone structure 102.

[0032] The rope magnetic control system 3 includes a rope 301 and a magnetic chuck 305 fixed to one end of the rope 301. The rope 301 passes through the lifting ring body 103 and suspends the magnetic chuck 305 below the lifting ring body 103. Lowering the rope 301 allows the magnetic chuck 305 to enter the outer shell 101. The magnetic chuck 305 attracts the float 201 and is used to release the blockage of the small diameter end of the inlet cone.

[0033] In practical implementation, to ensure the smooth lowering of the magnetic chuck in the slurry and to enhance the firmness of the connection between the rope 301 and the magnetic chuck 305, the rope magnetic control system 3 is also equipped with a fixing structure. The fixing structure includes a counterweight ball 302, a connector, and an outer cover 303. The diameter of the counterweight ball 302 is larger than the diameter of the lifting ring body 103 and smaller than the inner diameter of the outer shell 101. The bottom end of the rope 301 passes through the counterweight ball 302 and is fixedly connected to the middle of the magnetic chuck 305 through the connector. The outer cover 303 is provided around the magnetic chuck 305 and is fixedly connected to the counterweight ball 302.

[0034] In this embodiment, the rope 301 has a scale with a graduation accuracy of 1 cm and a breaking load of not less than 500 kg. The counterweight ball 302 is made of stainless steel, the connecting parts are screws 304, the outer cover 303 is made of stainless steel, and the magnetic chuck 305 uses N40 neodymium magnets. A rubber ring 306 to prevent detachment is provided between the N40 neodymium magnet and the outer cover 303. In specific implementation, the magnetic force of the magnetic chuck 305 is greater than the sum of the weight of the float 201 and the magnetic force of the annular magnetic strip, ensuring that the magnetic chuck 305 can attract the float 201 in the slurry and suspend it on the top of the outer shell 101.

[0035] This invention also provides a method for magnetic grouting with a drilled fractured section, employing the aforementioned magnetic grouting device for a drilled fractured section, comprising the following steps:

[0036] Step 1: Place the float 201 inside the inlet cone. The float 201 is sealed at the small diameter end of the inlet cone by gravity and the magnetic attraction of the annular magnetic strip.

[0037] Step Two (Grouting Stage): The grout is injected from the top of the outer shell 101 and stored in the space above the contact point between the inlet cone of the outer shell 101 and the float 201. At this time, the grout compresses the float 201 and the rubber gasket (202) to ensure tight contact, further guaranteeing the airtightness of the seal. The grout used is high-strength early-setting cement grout with a water-cement ratio (weight ratio of mixing water to cement) of 0.8:1-1:1. High-strength early-setting cement grout refers to cement grout with a compressive strength of not less than 50MPa after 28 days of hardening, an initial setting time of 5-30 minutes, a final setting time of 1-6 hours, and an early strength (1 day) that can reach more than 50% of the design strength.

[0038] Step 3 (Lowering Stage): Tighten rope 301 to confine counterweight ball 302 and magnetic chuck 305 to the bottom of the lifting ring body; align cylinder 1 with the borehole, and continue to lower rope 301 to slowly and gradually lower cylinder 1 with slurry until cylinder 1 is placed at the bottom of the borehole.

[0039] Step 4 (Release Stage): After the cylinder 1 reaches the bottom of the borehole, continue to lower the rope 301. The magnetic chuck 305 falls into the inlet cone under gravity and attracts the float 201. Then, the rope (301) is pulled back up until the counterweight ball 302 abuts against the bottom of the lifting ring body 103, thereby releasing the blockage of the float 201 on the small diameter end of the inlet cone. The slurry flows through the throat and outlet cone and then accelerates out from the bottom of the outer shell 101. Continue to pull the rope 301 back up to lift the cylinder 1 out of the borehole.

[0040] After the counterweight ball 302 comes into contact with the bottom of the lifting ring body 103, the cylinder 1 is lifted out of the borehole in two stages: In the first stage, during the slurry discharge process, the rope 301 needs to be steadily pulled up to lift the cylinder 1 from the bottom of the borehole slowly until all the slurry has flowed out. In the second stage, after ensuring that the slurry has been completely discharged, the rope 301 can be pulled up faster to lift the cylinder 1 out of the borehole.

[0041] Step 5 (Reset Stage): After the cylinder 1 is hoisted out of the drill hole, remove the float 201 and put it into the cylinder 1. The float 201 will automatically reset and seal.

[0042] Through testing, this invention can complete grouting operations in boreholes up to 300m deep. By using a cylinder 1 with a double-cone structure 102, a magnetic float valve structure 2, and a rope magnetic control system 3 with a scale, the grouting device is made lightweight and efficient, suitable for complex terrain environments, and has low cost and convenient operation. It solves the problem that traditional equipment is difficult to carry out grouting operations when the borehole depth is greater than 100m.

[0043] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A drilling broken zone magnetic suction type grouting device, characterized in that, include: The cylinder (1) includes a tubular outer shell (101), a lifting ring structure disposed on the top of the outer shell (101), and a double cone structure (102) disposed on the bottom of the outer shell (101). The double cone structure (102) includes an inlet cone and an outlet cone, both of which are conical shell structures. The small diameter ends of the inlet cone and the outlet cone are connected to each other. The slurry flows into the double cone structure (102) from the large diameter end of the inlet cone and flows out from the large diameter end of the outlet cone. The magnetic float valve structure (2) includes a float (201) made of ferromagnetic material and a magnetic strip arranged circumferentially at the small diameter end of the inlet cone; the float (201) is limited to the inlet cone and blocked at the small diameter end of the inlet cone by the magnetic attraction force of the magnetic strip and gravity; The rope magnetic control system (3) includes a rope (301) and a magnetic chuck (305) fixed to one end of the rope (301). The rope (301) passes through the ring structure and suspends the magnetic chuck (305) below the ring structure. Lowering the rope (301) causes the magnetic chuck (305) to attract the float (201), which is used to release the blockage of the small diameter end of the inlet cone by the float (201).

2. The broken zone magnetic grouting device for drilling holes according to claim 1, characterized in that, The magnetic float valve structure (2) also includes a buffer washer, which is circumferentially arranged on the inner wall of the small diameter end of the inlet cone, and the magnetic strip is arranged inside the buffer washer.

3. The drilling and crushing magnetic grouting device as described in claim 1, characterized in that, The lifting ring structure includes a lifting ring body (103) suspended above the outer shell (101) and two or more fixing claws (104). The top of the fixing claws is evenly connected to the lifting ring body (103), and the bottom of the fixing claws is fixedly connected to the outer shell (101) by fasteners.

4. The drilling and crushing magnetic grouting device as described in claim 3, characterized in that, The rope magnetic control system (3) is also provided with a fixing structure, which includes a counterweight ball (302) and a connector. The diameter of the counterweight ball (302) is larger than the diameter of the lifting ring body (103) and smaller than the inner diameter of the outer shell (101). The bottom end of the rope (301) is inserted into the counterweight ball (302). The counterweight ball (302) is fixedly connected to the middle of the magnetic chuck (305) through the connector.

5. The drilling and crushing magnetic grouting device as described in any one of claims 1-4, characterized in that, The inlet cone has a cone angle of 20°-23°, and the outlet cone has a cone angle of 10°-15°.

6. A method for magnetic grouting with a borehole fracture, employing the magnetic grouting device for a borehole fracture as described in claim 5, characterized in that... Includes the following steps: Step 1: Place the float (201) inside the inlet cone. The float (201) is sealed at the small diameter end of the inlet cone by gravity and magnetic attraction of the annular magnetic strip. Step 2: Inject the slurry from the top of the cylinder (1) and store the slurry in the space above the contact point between the inlet cone and the float (201); Step 3: Tighten the rope (301) to confine the counterweight ball (302) and magnetic chuck (305) to the bottom of the lifting ring body (103); lower the rope (301) to place the cylinder (1) at the bottom of the borehole; Step 4: Continue to lower the rope (301) and lower the magnetic chuck (305) into the inlet cone. After attracting the float (201), pull the rope (301) back up until the counterweight ball (302) abuts against the bottom of the lifting ring body (103), thereby releasing the magnetic float (201) from blocking the small diameter end of the inlet cone. The slurry flows into the outlet cone and then flows out from the bottom of the cylinder (1). The cylinder (1) is then lifted out of the borehole.

7. The magnetic grouting method for drilling and fracturing as described in claim 6, characterized in that, The slurry is a high-strength, early-setting cement slurry with a water-cement ratio of 0.8:1 to 1:

1.

8. The magnetic grouting method for drilling and fracturing as described in claim 6 or 7, characterized in that, Step four involves two stages of hoisting the cylinder (1) out of the borehole: In the first stage, during the slurry flow, the rope (301) is steadily pulled upward to slowly hoist the cylinder (1) from the bottom of the borehole. In the second stage, after all the slurry has flowed out, the cylinder (1) is hoisted out of the borehole.

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