Reverse grouting device and method
By combining the plastic sleeve with the sealing nylon tube and the guide nylon tube, the problems of cement slurry backflow and easy damage to the reverse grouting device are solved, achieving uniform injection and sealing of cement slurry and improving the durability of the device.
Patent Information
- Application Number
- CN202511990710.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-26
- Publication Date
- 2026-02-27
AI Technical Summary
In existing reverse grouting devices, cement slurry tends to flow back into the plastic sleeve, and the spring-reset backstop device is complex to manufacture and easily damaged.
It adopts a combination structure of plastic sleeve, sealing nylon tube, guide nylon tube and orifice sealing component, and achieves guidance and sealing through threaded connection to prevent cement slurry backflow.
It achieves reverse uniform injection and effective sealing of cement slurry, avoids backflow of cement slurry, simplifies the device structure, and improves the durability of the device.
Smart Images
Figure CN121576044A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of drilling construction technology for in-situ leaching uranium mining, and specifically relates to a reverse grouting device and method. Background Technology
[0002] The well completion process of in-situ immersion drilling mainly includes open-hole drilling, plastic casing installation, cementing of the annular space outside the well casing, and construction of a filter in the formation section. Traditionally, the cementing of the annular space outside the well casing uses forward grouting, where a grouting pipe is lowered into the annular space between the plastic casing and the open hole, and cement, mixed evenly on the surface, is injected into the underground annular space via a mud pump. This method suffers from uneven grouting and is prone to damaging the plastic casing. With the development of cutting-and-cover drilling technology, reverse grouting technology, which involves lowering the grouting pipe into the plastic casing, has also developed. Reverse grouting offers advantages such as uniform grouting and no damage to the casing, but it also carries the risk of injecting cement slurry backwards into the plastic casing, affecting drilling performance or even damaging the well. Preventing the backflow of cement slurry into the plastic casing is crucial for reverse grouting.
[0003] The existing reverse grouting device includes a drainage component and a squeezing component. During operation, the spring inside the grouting device is squeezed by the grouting pipe, which connects the water passage hole and the grout outlet hole inside the grouting device to achieve the purpose of grouting. After the operation is completed, the spring returns to its original position, which closes the water passage hole and the grout outlet hole to prevent cement grout from flowing back into the plastic sleeve. This method is safe and efficient, but it also has certain disadvantages, mainly in that the tools are complex to manufacture and easy to be damaged. Summary of the Invention
[0004] The purpose of this invention is to provide a reverse grouting device and method, which solves the problems of cement grout flowing back into the plastic sleeve and the difficulty in manufacturing and easy damage of the spring reset backstop device in existing reverse grouting devices.
[0005] The technical solution adopted by the present invention to solve its technical problem is: a reverse grouting device, wherein the device includes: a plastic sleeve, the bottom of the plastic sleeve is fixedly connected to the outer edge of a concentric cylindrical sealing nylon tube, the upper inner edge of the sealing nylon tube is connected to the lower part of a guide nylon tube, the bottom grouting pipe is threadedly connected to the inside of the guide nylon tube, and an ordinary grouting pipe is also threadedly connected to the bottom grouting pipe. The top of the plastic sleeve is also provided with a central orifice sealing component for the ordinary grouting pipe to pass through a small hole.
[0006] In the aforementioned reverse grouting device, the upper outer edge of the sealing nylon tube is provided with threads, and the sealing nylon tube is connected to the bottom of the bottommost plastic sleeve by threaded connection.
[0007] In the aforementioned reverse grouting device, the plastic sleeves are made of UPVC material, and the plastic sleeves are connected by pipe clamps, which are also made of UPVC plastic pipes.
[0008] In the aforementioned reverse grouting device, the guide nylon tube is a hollow, ellipsoidal shape with conical ends and a cylindrical middle. The conical ends of the guide nylon tube are fitted with threaded female threads. The upper inner ring of the sealing nylon tube is an inverted cone. The upper part of the sealing nylon tube is matched and connected to the lower part of the guide nylon tube.
[0009] In the aforementioned reverse grouting device, the bottom grouting pipe comprises upper and lower sections. The bottom of the upper section and the top of the lower section of the bottom grouting pipe are both provided with threaded male threads. The upper and lower sections of the bottom grouting pipe are respectively connected to the upper and lower conical ends of the guide nylon pipe by threaded connection.
[0010] In the aforementioned reverse grouting device, the orifice sealing component is a barrel-shaped structure, which is connected to the plastic sleeve by threads at the bottom of the barrel, and a pressure gauge is also provided on the side end of the orifice sealing component.
[0011] A method for operating a reverse grouting device, wherein the method includes:
[0012] Step 1: After the open-hole drilling in the grouting area is completed, connect the bottom of the sealing nylon pipe to the plastic casing and lower it into the open-hole. Then lower the other plastic casings one by one, connecting them with pipe clamps, until the uppermost well casing is lowered.
[0013] Step 2: After fixing the bottom grouting pipe and the guide nylon pipe together, lower both of them. Then lower the ordinary grouting pipe one by one until the bottom grouting pipe is 5-10 meters away from the sealing nylon pipe. Then start pumping clean water into the plastic sleeve until water returns from the orifice.
[0014] Step 3: Continue to slowly lower the ordinary grouting pipe until the guide nylon pipe encounters resistance. Slowly shake the ordinary grouting pipe until the guide nylon pipe is inserted into the sealing nylon pipe, and then install the sealing device.
[0015] Step 4: Inject cement slurry into the ordinary grouting pipe using a mud pump, while observing the pressure gauge of the sealing device. If the pressure is less than 0.3 MPa, continue injecting cement slurry until it returns from the borehole. If the pressure is greater than or equal to 0.3 MPa, stop grouting until the pressure is less than 0.3 MPa, then continue injecting cement slurry until it returns from the borehole.
[0016] Step 5: After the grouting is completed, wait for the cement to basically solidify, then remove the sealing device and pull out the ordinary grouting pipes one by one until the bottom grouting pipe and the guide nylon pipe are pulled out together to complete the reverse grouting.
[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: The reverse grouting device and method provided by the present invention, on the one hand, guides the grouting process through the device structure design, so that the bottom of the grouting pipe can be smoothly inserted into the bottom of the plastic pipe, and the cement grout is injected into the bottom of the well along the grouting pipe and flows back through the outer annular space of the plastic pipe to the orifice, thereby realizing reverse grouting; on the other hand, the closed conical pipe structure achieves a sealing effect and prevents the backflow of cement grout. Attached Figure Description
[0018] Figure 1 The diagram shown is an overall structural schematic of a reverse grouting device according to the present invention.
[0019] Figure 2 The diagram shown is a disassembled structural schematic of a reverse grouting device according to the present invention.
[0020] The following are the reference numerals: 1. Open-hole drilling; 2. Plastic casing; 3. Ordinary grouting pipe; 4. Bottom grouting pipe; 5. Guide nylon pipe; 6. Sealing nylon pipe; 7. Wellhead sealing component. Detailed Implementation
[0021] To address the problems of cement slurry backflow into the plastic sleeve and the difficulty in manufacturing and easy damage of the spring-loaded backstop device in existing reverse grouting devices, this invention provides a reverse grouting device and method. Figures 1-2 As shown, the device includes: a plastic sleeve 2, which is made of UPVC material, and the plastic sleeves 2 are connected by a pipe clamp, which is also made of UPVC plastic pipe. The bottom of the plastic sleeve 2 is fixedly connected to the outer edge of a concentric cylindrical sealing nylon tube 6. The upper outer edge of the sealing nylon tube 6 is provided with threads, and the sealing nylon tube 6 is connected to the bottom of the bottommost plastic sleeve 2 by threaded connection.
[0022] The upper inner edge of the sealing nylon tube 6 is connected to the lower part of the guide nylon tube 5. The bottom grouting tube 4 is threadedly connected to the inside of the guide nylon tube 5. A regular grouting tube 3 is also threadedly connected to the bottom grouting tube 4. The top of the plastic sleeve 2 is also provided with an orifice sealing component 7, which allows the regular grouting tube 3 to pass through a small hole. The orifice sealing component 7 has a barrel-shaped structure and is threadedly connected to the plastic sleeve 2 through the bottom thread. A pressure gauge is also provided on the side end of the orifice sealing component 7.
[0023] The guide nylon tube 5 is a hollow, ellipsoidal shape with conical ends and a cylindrical middle. The conical ends of the guide nylon tube 5 have threaded female threads inside. The upper inner ring of the sealing nylon tube 6 is an inverted cone. The upper part of the sealing nylon tube 6 is matched and connected to the lower part of the guide nylon tube 5. The bottom grouting tube 4 includes upper and lower sections. Both the bottom of the upper section and the top of the lower section of the bottom grouting tube 4 have threaded male threads. The upper and lower sections of the bottom grouting tube 4 are respectively threaded to the upper and lower conical ends of the guide nylon tube 5.
[0024] The operation method of the reverse grouting device includes:
[0025] Step 1: After the open hole drilling 1 in the grouting area is completed, the sealing nylon pipe 6 is connected to the bottom of the plastic casing 2 and then lowered into the open hole drilling 1. Then, other plastic casings 2 are lowered one by one. The plastic casings 2 are connected by pipe clamps until the uppermost well pipe is lowered.
[0026] Step 2: After fixing the bottom grouting pipe 4 and the guide nylon pipe 5 together, lower both of them. Then lower the ordinary grouting pipes 3 one by one until the bottom grouting pipe 4 is 65-10 meters away from the sealing nylon pipe. Then start pumping clean water into the plastic sleeve 2 until water returns from the orifice.
[0027] Step 3: Continue to slowly lower the ordinary grouting pipe 3 until the guide nylon pipe 5 encounters resistance. Slowly shake the ordinary grouting pipe 3 until the guide nylon pipe 5 is inserted into the sealing nylon pipe 6, and then install the sealing device 7.
[0028] Step 4: Inject cement slurry into the ordinary grouting pipe 3 using a mud pump, while observing the pressure gauge change of the sealing device 7. If the pressure is less than 0.3 MPa, continue injecting cement slurry until cement slurry returns from the borehole. If the pressure is greater than or equal to 0.3 MPa, stop grouting until the pressure is less than 0.3 MPa, then continue injecting cement slurry until cement slurry returns from the borehole.
[0029] Step 5: After the grouting is completed, wait for the cement to basically solidify, then remove the sealing device 7 and pull out the ordinary grouting pipes 3 one by one until the bottom grouting pipe 4 and the guide nylon pipe 5 are pulled out together to complete the reverse grouting.
[0030] Example 1
[0031] The open-hole drilling 1 described in this embodiment is a vertical open-hole drilling, constructed using a 215mm diameter drill bit, with a borehole diameter of 220mm. In this embodiment, the plastic casing 2 of the reverse grouting device is a UPVC plastic pipe with specifications of 148mm*10mm and a single length of 8000mm. The plastic casings 2 are connected by pipe clamps, which are also made of UPVC plastic pipe with specifications of 160mm*15mm. The ordinary grouting pipe 3 is a hollow steel pipe made of 304 stainless steel with specifications of 50mm*5mm and a single length of 6m. The bottom grouting pipe 4 is a hollow steel pipe made of 304 stainless steel, comprising upper and lower sections. The upper section has specifications of 50mm*5mm and a length of 6m, while the bottom has a 100mm long, 48mm outer diameter, and 44mm inner diameter threaded male thread. The lower section measures 50mm x 5mm and is 240mm long. The upper part has a 100mm long male thread with an outer diameter of 48mm and an inner diameter of 44mm. The upper and lower sections of the bottom grouting pipe 4 are threaded to the upper and lower ends of the guide nylon pipe 5, respectively. The guide nylon pipe 5 is a concentric cylindrical ellipsoid with cones at both ends and a hollow cylinder in the middle. It has a total length of 200mm, a middle cylinder length of 150mm, an outer diameter of 100mm, and an inner diameter of 60mm, and the cones at both ends are 20mm long with a 45° chamfer. The top cone faces upwards, and the bottom cone faces downwards. The cones at both ends have female threads inside, which are threaded to the upper and lower sections of the bottom grouting pipe 4, respectively. The sealing nylon tube 6 is a concentric cylinder with a length of 130mm, an outer diameter of 160mm, and an inner diameter of 60mm. The upper outer ring is threaded with a single-thread right-hand rectangular thread with a pitch of 6mm and a thread length of 60mm. It has an outer diameter of 145mm and an inner diameter of 140mm, and is threadedly connected to the plastic sleeve 2. The upper inner ring is an inverted cone with a length of 10mm and a chamfer of 45°. The upper part of the sealing nylon tube 6 is matched and connected to the lower part of the guide nylon tube 5. The orifice sealing component 7 is a barrel-shaped steel pipe with a 50mm diameter hole in the middle of the upper part and a pressure gauge mounted on the side. The top of the orifice sealing component 7 is sealed, while the bottom is open and threaded. The top of the barrel measures 148mm x 10mm, and the barrel height is 30mm. The top of the barrel is threadedly connected to the top of the plastic sleeve 2.
[0032] It should be noted that the combination of the technical features in the embodiments of the present invention is not limited to the combination methods described in the embodiments of the present invention or the combination methods described in the specific embodiments. All technical features described in the present invention can be freely combined or combined in any way, unless there is a contradiction between them.
[0033] 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, 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 reverse grouting device, characterized in that, The device includes: a plastic sleeve (2), the bottom of which is fixedly connected to the outer edge of a concentric cylindrical sealing nylon tube (6), the upper inner edge of the sealing nylon tube (6) is connected to the lower part of a guide nylon tube (5), the bottom grouting tube (4) is threadedly connected to the inside of the guide nylon tube (5), and a regular grouting tube (3) is also threadedly connected to the bottom grouting tube (4). The top of the plastic sleeve (2) is also provided with a central orifice sealing component for the regular grouting tube (3) to pass through a small hole.
2. The reverse grouting device according to claim 1, characterized in that, The upper outer edge of the sealing nylon tube (6) is provided with threads, and the sealing nylon tube (6) is connected to the bottom of the bottom plastic sleeve (2) by threaded connection.
3. The reverse grouting device according to claim 1, characterized in that, The plastic sleeves (2) are made of UPVC material, and the plastic sleeves (2) are connected by pipe clamps, which are made of UPVC plastic pipes.
4. The reverse grouting device according to claim 1, characterized in that, The guide nylon tube (5) is a hollow ellipsoid with conical top and bottom ends and cylindrical middle. The conical top and bottom ends of the guide nylon tube (5) are provided with threaded female wires. The upper inner ring of the sealing nylon tube (6) is an inverted cone. The upper part of the sealing nylon tube (6) is matched and connected to the lower part of the guide nylon tube (5).
5. A reverse grouting device according to claim 4, characterized in that, The bottom grouting pipe (4) includes upper and lower sections. The bottom of the upper section and the top of the lower section of the bottom grouting pipe (4) are provided with threaded male threads. The upper and lower sections of the bottom grouting pipe (4) are respectively connected to the upper and lower conical ends of the guide nylon pipe (5) by threaded connection.
6. The reverse grouting device according to claim 1, characterized in that, The orifice sealing component (7) has a barrel-shaped structure and is threaded to the plastic sleeve (2) through the bottom thread. A pressure gauge is also provided on the side of the orifice sealing component (7).
7. An operation method for a reverse grouting device, characterized in that, The method includes: Step 1: After the open hole drilling (1) in the grouting area is completed, the sealing nylon pipe (6) is connected to the bottom of the plastic casing (2) and then lowered into the open hole drilling (1). Then, other plastic casings (2) are lowered one by one. The plastic casings (2) are connected by pipe clamps until the uppermost well pipe is lowered. Step 2: After fixing the bottom grouting pipe (4) and the guide nylon pipe (5) together, lower them in one by one. Then lower the ordinary grouting pipe (3) one by one until the bottom grouting pipe (4) is 5-10 meters away from the sealing nylon pipe (6). Then start pumping clean water into the plastic sleeve (2) until water returns from the orifice. Step 3: Continue to slowly lower the ordinary grouting pipe (3) until the guide nylon pipe (5) encounters resistance. Slowly shake the ordinary grouting pipe (3) until the guide nylon pipe (5) is inserted into the sealing nylon pipe (6). Then install the sealing device (7). Step 4: Inject cement slurry into the ordinary grouting pipe (3) using a mud pump, and observe the pressure gauge change of the sealing device (7). If the pressure is less than 0.3 MPa, continue injecting cement slurry until cement slurry returns from the hole. If the pressure is greater than or equal to 0.3 MPa, stop grouting until the pressure is less than 0.3 MPa, then continue injecting cement slurry until cement slurry returns from the hole. Step 5: After the grouting is completed, wait for the cement to basically solidify and then remove the sealing device (7). Pull out the ordinary grouting pipes (3) one by one until the bottom grouting pipe (4) and the guide nylon pipe (5) are pulled out together to complete the reverse grouting.