A dynamic gain dual slurry static mixer for boreholes

Abstract

This invention discloses a dynamic-gain slurry static mixer for boreholes, comprising a mixer jacket and an end connector. Inside the mixer jacket are installed a front connector, the mixer jacket itself, a dynamic axial mixing element, a unidirectional mixing base, a mandrel, a blade assembly, and a spring. The front connector, dynamic axial mixing element, unidirectional mixing base, spring, and mixer jacket constitute an axial dynamic mixing unit; the mandrel, blade assembly, mixer jacket, and end connector constitute a static mixing unit. It can be connected to inner and outer continuous tubing via a continuous tubing support, enabling the direct and separate delivery of two slurries to the mixer inlet. Mixing is then performed through a bottom-hole mixer, significantly delaying the slurry gelation time, preventing grout blockage accidents, and substantially improving the mixing efficiency and uniformity of the slurry within the borehole.

Description

Technical Field

[0001] This invention belongs to the field of filling and grouting drilling tools, specifically relating to a dynamic gain grout static mixer for use in directional long-distance horizontal drilling. Background Technology

[0002] To effectively control mine water inflow and ensure mine water safety, coal mines mainly carry out "exploration, prevention, blocking, dredging, drainage, interception, and monitoring" work. Injecting grout into rock fissures or broken rock layers through drilling can achieve the purpose of water blocking and reinforcement. After comparing the effectiveness of various construction techniques, cement-water glass can effectively seal rock and soil fissures and block the seepage path of groundwater. The use of non-toxic, harmless cement-water glass grout with controllable setting time or other new chemical materials as grouting materials is becoming increasingly common. Using an in-drill mixer can improve the mixing effect of the two grouts. A static mixer is a mixing device without moving elements, mainly relying on the fluid's own energy and the structure of stationary elements to change the fluid's flow state within the pipe.

[0003] Borehole grouting involves constructing linear grouting channels in thick rock formations through surface straight boreholes, surface directional horizontal boreholes, or downhole horizontal boreholes. Grout is injected into the borehole using a grouting pump, and then diffuses along the fractures or cavities exposed by the borehole, sealing water passages in the rock formation. While existing static mixers perform multiple divisions, rotations, and recombinations of the fluid before finally achieving mixing, their shear capacity is relatively weak and difficult to adjust; therefore, mixing efficiency and uniformity need further improvement.

[0004] Unlike static mixers, dynamic mixers rely on mechanical power components to force the fluid system to flow, achieving uniform mixing of the slurry. However, implementing a powered component in deeper holes is extremely difficult, and using cables or high-pressure slurry generators within the borehole presents numerous technical challenges. Furthermore, in grouting projects with significant hole depths, the mixed slurry may solidify within the borehole in fissures not yet injected into the soil or rock mass, potentially clogging the borehole. Summary of the Invention

[0005] To address the aforementioned technical problems of existing slurry mixers, such as the possibility of solidification and borehole blockage due to long slurry transport distances, and the relatively weak shearing capacity and difficulty in adjustment of existing static mixers despite multiple division, rotation, and recombination of the fluid to achieve final mixing, the present invention aims to provide a dynamic-gain static slurry mixer for boreholes. This mixer injects slurry into rock fissures or broken rock layers through the borehole to achieve grouting and water plugging, effectively avoiding borehole blockage accidents caused by mixed slurry. It also improves the mixing efficiency and effect of traditional static mixers and enhances the mixing efficiency and uniformity of slurry within the borehole.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A dynamic gain slurry static mixer for boreholes includes a mixer jacket and an end connector, characterized in that the front connector, the mixer jacket, a dynamic axial mixing element, a unidirectional mixing base, a mandrel, a blade assembly, and a spring are installed inside the mixer jacket, wherein:

[0008] The front-end connector, dynamic axial mixing element, unidirectional mixing base, spring and mixer sleeve constitute the axial dynamic mixing unit;

[0009] The mandrel, blade assembly, mixer jacket, and end connectors constitute a static mixing unit;

[0010] The front connector is connected to a dual-slurry continuous pipe connector bracket, and the front connector and the end connector are fixed to both ends of the mixer jacket by threads; the unidirectional mixing base is fixed to the mixer jacket by pins.

[0011] The dynamic axial mixing element is installed in conjunction with the front connector, and the other end is connected to a spring fixed to the dynamic axial mixing element; the mandrel is installed on the mixing base, and the blade assembly is fixed on the mandrel; the blade assembly consists of multiple helical blades at different angles.

[0012] According to the present invention, the dual-slurry continuous pipe joint frame has pipe threads on both the inside and outside, and the small-diameter continuous oil pipe and the large-diameter continuous oil pipe are connected and fixed by the inner and outer pipe threads. The small-diameter continuous oil pipe has an arc-shaped hole in the middle, and the slurry of the large-diameter continuous oil pipe passes through the arc-shaped hole.

[0013] Specifically, the outer diameter of the dynamic axial mixing element is provided with a series of spherical moving grooves arranged along the axial direction, and the cross section of the spherical moving grooves is rectangular or arc-shaped; on the inner wall of the mixer jacket, a spherical stationary groove is provided corresponding to the inner groove on the outer diameter of the dynamic axial mixing element, which is offset from the inner groove by one position.

[0014] The borehole dynamic gain slurry static mixer of the present invention has the following technical advantages compared with existing mixers:

[0015] 1. It can be connected to the inner and outer continuous tubing via a continuous pipe rack, so that the two slurries can be directly delivered to the inlet of the mixer and mixed through the bottom mixer, which greatly delays the gel time of the slurry and avoids grouting blockage accidents.

[0016] 2. An in-hole dynamic-gain slurry static mixer is constructed using axial dynamic mixing units and static mixing units. The dynamic gain creates a slurry transfer cavity mixing chamber, enabling repeated shearing and tumbling actions. This solves the problems of existing static mixers, which, although the fluid is repeatedly divided, rotated, and combined before final mixing, have weak shearing capabilities and are relatively difficult to adjust. It achieves short-distance slurry segmentation, rotation, and shearing, effectively enhancing the dynamic gain of slurry mixing. This significantly improves the mixing efficiency and uniformity of the slurry in the borehole.

[0017] 3. Based on the pump flow rate and concentration value corresponding to different diameter continuous pipes, the setting time and setting strength of the mixed slurry will vary accordingly. The setting test parameters of slurry with different ratios can be adjusted accordingly, and the length and cavity size can be adjusted to achieve the best construction efficiency. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the dynamic gain slurry static mixer in borehole according to the present invention;

[0019] Figure 2 These are schematic diagrams of the front-end connector structure; where (a) is the first structural form and (b) is the second structural form.

[0020] Figure 3 This is a schematic diagram of a continuous pipe joint frame structure;

[0021] Figure 4 This is a schematic diagram of the dynamic axial hybrid element structure;

[0022] Figure 5 This is a schematic diagram of the mixer jacket structure;

[0023] Figure 6 This is a schematic diagram of the cavity mixing cavity structure, where (a) shows the first position of the cavity mixing cavity and (b) shows the second position of the cavity mixing cavity, with the two positions alternating.

[0024] Figure 7 This is a schematic diagram of a unidirectional hybrid base structure;

[0025] The markings in the diagram represent: 1. Front connector, 2. Mixer outer sleeve, 3. Dynamic axial mixing element, 4. One-way mixing base, 5. Mandrel, 6. Blade assembly, 7. End connector, 8. Spring, 9. Double slurry continuous tubing connector bracket; 2-1. Connecting thread, 2-2. Fixing part locking, 2-3. Spherical static groove, 3-1. Inner groove, 3-1. Sealing ring groove, 3-2. Spherical dynamic groove, 9-1. Small diameter continuous tubing, 9-2. Large diameter continuous tubing.

[0026] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Detailed Implementation

[0027] See Figure 1 This embodiment provides a dynamic gain slurry static mixer for boreholes, including a mixer jacket 2 and an end connector 7. Inside the mixer jacket 2 are installed a front connector 1, a mixer jacket 2, a dynamic axial mixing element 3, a unidirectional mixing base 4, a mandrel 5, a blade assembly 6, and a spring 8, wherein:

[0028] The front connector 1, dynamic axial mixing element 3, unidirectional mixing base 4, spring 8 and mixer sleeve 2 together form an axial dynamic mixing unit;

[0029] The core shaft 5, blade assembly 6, mixer jacket 2, and end connector 7 constitute a static mixing unit;

[0030] The front connector 1 is connected to a double slurry continuous pipe connector bracket 9. The front connector 1 and the end connector 7 are fixed to both ends of the mixer jacket 2 by threads. The unidirectional mixing base 4 is fixed to the mixer jacket 2 by pins.

[0031] The dynamic axial mixing element 3 is internally fitted with the front connector 1, and the other end is connected to the spring 8 fixed on the dynamic axial mixing element 3; the spindle 5 is mounted on the mixing base 4, and the blade group 6 is fixed on the spindle 5; the blade group 6 is composed of multiple helical blades at different angles.

[0032] In this embodiment, the front connector 1 has two forms: the first type is as follows Figure 2 As shown in (a), the front-end connector 1 can be connected to the inner and outer continuous tubing to realize the direct delivery of the two slurries to the inlet end of the dynamic gain slurry static mixer in the borehole in this embodiment, and then the slurry is mixed through the axial dynamic mixing unit; the second type is as follows Figure 2 As shown in (b), the front connector 1 can be directly connected to the drill pipe.

[0033] The structure of the dual-slurry continuous pipe joint frame 9 is as follows: Figure 3 As shown, two continuous oil pipes, 9-1 and 9-2, of different diameters, are connected to a dual-slurry continuous pipe joint bracket 9. The dual-slurry continuous pipe joint bracket 9 has threads on both the inside and outside, which connect and fix the two continuous oil pipes (9-1 and 9-2) of different diameters. The smaller diameter continuous oil pipe 9-1 has an arc-shaped hole in the middle, through which the slurry from the larger diameter continuous oil pipe 9-2 can pass. This allows for the direct, separate delivery of the two slurries to the mixer inlet.

[0034] The front connector 1 and the mixer jacket 2 of the axial dynamic mixing unit are connected by threads. The unidirectional mixing base 4 is fixed by a pin on the mixer jacket 2, and the dynamic axial mixing element 3 is installed between the mixer jacket 2 and the unidirectional mixing base 4. The dynamic axial mixing element 3 is annular, with its large end outer diameter equal to the inner diameter of the mixer jacket 2 and its small end outer diameter equal to the small inner diameter of the front connector 1. A series of axially arranged spherical moving grooves 3-2 are provided on the outer diameter of the dynamic axial mixing element 3. The cross-section of the spherical moving grooves 3-2 can be rectangular or arc-shaped. On the inner wall of the mixer jacket 2, corresponding to the spherical moving grooves 3-2 on the outer diameter of the dynamic axial mixing element 3, there is a spherical stationary groove 2-3 that is offset by one position from the spherical moving grooves 3-2.

[0035] The structure of the dynamic axial mixing element 3 is as follows: Figure 4 As shown, the dynamic axial mixing element 3 is annular, with its large end outer diameter equal to the inner diameter of the mixer jacket 2, and its small end outer diameter equal to the small inner diameter of the front connector 1. The sealing ring groove 3-1 is arranged along the small diameter of the front connector, and the spherical moving groove 3-2 is arranged along the large diameter. When the internal and external pressures are balanced, backflow of the slurry can be prevented.

[0036] The spherical moving grooves 3-2 can be arranged evenly or arranged from sparse to dense along the axial direction.

[0037] The structure of the mixer jacket 2 is as follows Figure 5 As shown, one end of it is a connecting thread 2-1, and a fixing slot 2-2 is set inside. The spherical static grooves 2-3 are evenly arranged along the axial direction of the mixer jacket 2 pipe wall, or they can be arranged from sparse to dense along the axial direction of the mixer jacket 2 pipe wall.

[0038] The spherical moving groove 3-2 of the dynamic axial mixing element 3 and the spherical static groove 2-3 of the mixer jacket 2 are combined at one position to form a cavity mixing chamber. Figure 6 (a) and Figure 6 (b) represents two positions of the cavity mixing cavity. During operation, the first and second positions of the cavity mixing cavity alternate back and forth.

[0039] The dynamic axial mixing element 3 achieves axial gain through slurry pressure and a spring 8 mounted on a unidirectional mixing base 4. When pressurized slurry pushes the dynamic axial mixing element 3 to compress the spring 8 and move axially, slurry transfer cavity mixing chambers are formed, which overlap and repeat shearing and flipping actions to achieve dynamic gain in mixing.

[0040] The unidirectional mixing base 4, as described above Figure 7 As shown, it is provided with mutually perpendicular through holes, through which the slurry with dynamic gain flows into its inner cavity.

[0041] The static mixing unit consists of a mandrel 5, a blade assembly 6, an end connector 7, and a mixer housing 2. One end of the mandrel 5 is mounted on the other side of the unidirectional mixing base 4. The blade assembly 6 is fixed to the mandrel 5 and consists of multi-lobed helical blades at different angles. The end connector 7 is threaded onto the mixer housing 2.

[0042] The borehole dynamic gain slurry static mixer provided in this embodiment forms a slurry transfer cavity mixing chamber with dynamic gain, which can repeatedly shear and flip, solving the problems of existing static mixers, which, although the fluid is divided, rotated, and combined multiple times to finally achieve mixing, have weak shearing ability and are relatively difficult to adjust. It realizes short-distance division, rotation, and shearing of slurry, effectively dynamically gaining slurry mixing effect, and can significantly improve the mixing efficiency and uniformity of slurry in borehole.

Claims

1. A dynamic gain slurry static mixer for boreholes, comprising a mixer jacket (2) and an end connector (7), characterized in that, The mixer housing (2) contains a front-end connector (1), a dynamic axial mixing element (3), a unidirectional mixing base (4), a spindle (5), a blade assembly (6), and a spring (8), wherein: The front connector (1), dynamic axial mixing element (3), unidirectional mixing base (4), spring (8) and mixer jacket (2) constitute the axial dynamic mixing unit; The mandrel (5), blade assembly (6), mixer jacket (2), and end connector (7) constitute a static mixing unit; The front connector (1) is connected to a double slurry continuous pipe connector bracket (9), and the front connector (1) and the end connector (7) are fixed to both ends of the mixer jacket (2) by threads; the unidirectional mixing base (4) is fixed to the mixer jacket (2) by pins; The dynamic axial mixing element (3) is internally fitted with the front connector (1); the spindle (5) is mounted on the unidirectional mixing base (4), and the blade assembly (6) is fixed on the spindle (5); the blade assembly (6) is composed of multi-lobed helical blades at different angles; the dynamic axial mixing element (3) achieves axial gain through slurry pressure and springs (8) mounted on the unidirectional mixing base (4); The outer diameter of the dynamic axial mixing element (3) is provided with a series of spherical moving grooves (3-2) arranged along the axial direction. The cross section of the spherical moving groove (3-2) is rectangular or arc-shaped. On the inner wall of the mixer jacket (2), a spherical stationary groove (2-3) is provided corresponding to the spherical moving groove (3-2) on the outer diameter of the dynamic axial mixing element (3). The spherical stationary groove (2-3) is offset from the spherical moving groove (3-2) by one position.

2. The in-hole dynamic gain slurry static mixer as described in claim 1, characterized in that, The dual-slurry continuous pipe joint bracket (9) has pipe threads on both the inside and outside, and connects and fixes the small-diameter continuous oil pipe (9-1) and the large-diameter continuous oil pipe (9-2) through the internal and external pipe threads.

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