Remedial fluid augmented in-situ direct push jetting tool and jetting method

Abstract

The application provides a kind of repair agent enhanced in-situ direct push injection drill and injection method with the functions of low-pressure direct push atomization injection for middle and high permeability formation and hydraulic fracturing-high pressure atomization injection for low permeability formation, and the core components include liquid hose, gas hose, flange, short connecting rod, nozzle seat, nozzle, drill bit, long curved liquid connecting pipe is connected with multiple nozzles arranged radially and uniformly through nozzle seat after penetrating flange, short straight gas connecting pipe is connected with injection hole through gas passage in the cavity of drill, water and various injection media share liquid passage, and air or nitrogen gas passes through gas passage; the drill represents in-situ direct push injection method and equipment with strong mobility, convenient operation, can adjust injection / injection mode according to the change of formation texture, cooperates with high pressure air flow wrapping and atomization function to strengthen in-situ transmission effect of agent.

Description

Technical Field

[0001] This invention belongs to the field of environmental remediation and relates to a direct-push injection drilling tool and injection method. In particular, it relates to the implementation of an in-situ remediation technology for contaminated soil and groundwater in the field of environmental remediation, which enhances the delivery of remediation agents (injection media in the form of aqueous solution, diluted mud, suspension, emulsion, etc.) in the underground target remediation area. Background Technology

[0002] Domestic and international underground agent delivery technologies used for in-situ remediation of contaminated sites, including contaminated soil and groundwater, can be divided into two main categories: in-situ mixing and in-situ injection.

[0003] In-situ mixing devices commonly use mixing heads mounted on traditional excavators, transforming the excavator into a mobile mixing unit. The mixing head can mix and blend various materials in situ. A chemical pumping system delivers the chemical injection solution via hoses to nozzles located between the mixing heads. The high-speed rotation of the mixing heads ensures the chemical is evenly mixed with the soil underground. The working depth of the mixing head is generally limited to 7-8 meters. In-situ deep mixing equipment is rarely used domestically or internationally; the equipment is very large, heavy, and lacks mobility. In-situ mixing equipment, regardless of depth, provides good uniformity of chemical diffusion within the equipment's reach. However, the diffusion range is directly limited by the outer dimensions of the mixing head or the device's underground operating area, resulting in a limited radius of influence. Furthermore, this technology causes significant disturbance to the site or strata, damaging the foundation's bearing capacity and easily leading to pollutant migration.

[0004] Common in-situ injection techniques include injection well injection, direct injection, and high-pressure jet injection. In other countries, there are also hydraulic fracturing and pneumatic fracturing techniques.

[0005] Injection wells are only suitable for injecting aqueous solutions or emulsions. Their advantage is that they can be reused, making them suitable for situations where multiple injections of reagents are required. However, their disadvantages include that they cannot be used for injecting thin mud or suspensions containing significant particulate matter. The influence range of injection wells is significantly affected by heterogeneous formations, exhibiting obvious anisotropy and heterogeneity. The influence range is poor in relatively low-permeability formations. If the target remediation area has a large depth span, multiple injection wells or nested wells targeting different depth ranges need to be set up at the same location. If the target remediation area is large, a large number of injection wells need to be constructed, increasing the initial fixed cost and lengthening the construction time.

[0006] Direct-push injection technology utilizes a direct-push drilling rig to push a drill string with nozzles directly to the target depth within the target remediation area. The chemical agent is then injected into the soil layer of the target remediation area through a pump, a channel within the drill pipe (usually a single channel), and the nozzle. The advantages of direct-push injection technology include lightweight and highly mobile drilling rigs, direct implementation for speed, minimal disturbance to the formation, and wide applicability to a wide range of soil types, suitable for most unconsolidated strata, including clay sites, with a maximum operating depth of up to 30 meters. Direct-push injection technology generally recommends low-pressure, low-flow-rate injection, thus limiting its impact radius in low-permeability clay sites.

[0007] High-pressure jet grouting technology originated from high-pressure jet grouting foundation treatment technology in the construction industry, originally used for foundation reinforcement, water-stop curtains, and slope protection piles in construction projects. In its application to contaminated site remediation, high-pressure jet grouting technology primarily involves inserting a grouting pipe (drill rod) with a special nozzle into a predetermined depth within the target remediation area through a borehole. The chemical injection solution is then sprayed from the nozzle, and the grouting pipe with the nozzle is simultaneously spiraled upwards during injection. The high-pressure liquid flow cuts and mixes the soil layer, ensuring thorough mixing of the chemical solution with the contaminated soil. Currently, the most advanced method is the triple (concentric) pipe method, with three channels respectively delivering high-pressure water flow, high-pressure grout flow, and an outer jacket of compressed air. High-pressure jet grouting has advantages such as a wide range of applicable soil types, large injection depth, high efficiency, and the ability to inject at a fixed depth. However, its influence radius is not good for medium- and low-permeability strata, generally within 1 meter. Due to the spiral cutting effect of the high-pressure water flow, it causes a certain degree of disturbance to the soil layer. The equipment is large and cumbersome, with poor mobility, making it unsuitable for working in complex terrain. It lacks precise injection based on the different levels of pollution in the strata, instead using a uniform injection volume regardless of the degree of pollution or whether there is any pollution at all, resulting in poor targeting of the agent and waste of the agent.

[0008] Hydraulic fracturing and pneumatic fracturing technologies are used to address the shortcomings of traditional injection techniques in low-permeability formations. Hydraulic fracturing requires drilling and installing PVC casing, or using a double-packer injection system. At the desired fracture depth, a rotating high-pressure (>20MPa) water jet creates a dish-shaped inlet. Then, a grouting pump is used to inject proppant (such as a water / sand mixture) at low pressure, extending horizontally outwards from the inlet. This typically creates one or two large fractures, 1-2 cm thick, with lengths ranging from 5 to over ten meters. Due to the proppant, the fractures do not close, creating a highly permeable channel. Hydraulic fracturing operations are relatively time-consuming, and the depth intervals are generally large (approximately 3-6 meters). Pneumatic fracturing also involves drilling first, with the option of using PVC casing optional. A double packer is used to create a gap of approximately 2 / 3 meter within the borehole / well. High-pressure, high-flow air is injected horizontally into the soil layer through nozzles between the packers, creating dense, divergent fine fractures nearby and several coarser fractures further away, with a similar extension rate to hydraulic fracturing. The operation time is short, requiring only 20-30 seconds. The maximum application depth of pneumatic fracturing is approximately 25 meters underground. Pneumatic fracturing can be applied at depth intervals of 0.7-1 meter. Hydraulic fracturing and pneumatic fracturing are specialized technologies for enhancing agent delivery in low-permeability formations. They require drilling first, followed by casing or the deployment of a double packer injection system. The operation is cumbersome, time-consuming, and costly, with limited availability of specialized equipment. The applicable scenarios are limited (only applicable to low-permeability formations), lacking multi-scenario compatibility or universal applicability.

[0009] In short, existing in-situ injection equipment and technologies each have their own applicability, but there is still a lack of technology and equipment that can be used for low-pressure injection in medium and high permeability formations, overcome low permeability formations to achieve fracturing and injection, and can perform targeted and precise injection of agents according to the characteristics of contamination distribution, avoiding agent waste and formation disturbance. Summary of the Invention

[0010] In order to solve the above-mentioned technical problems in the background art, the present invention provides a repair agent enhanced in-situ direct push injection drilling tool and injection method that are highly mobile, easy to operate, and can achieve precise agent delivery.

[0011] To achieve the above objectives, the present invention adopts the following technical solution:

[0012] A repair agent-enhanced in-situ direct-push injection drilling tool, characterized in that: the repair agent-enhanced in-situ direct-push injection drilling tool includes a short rod, a nozzle seat, a nozzle, a drill bit, a flange, a gas channel, a liquid connecting pipe, and a gas connecting pipe; the short rod is a hollow tubular structure; the flange and the drill bit are respectively disposed at both ends of the short rod; the nozzle seat is disposed axially inside the short rod; a spray hole communicating with the interior of the short rod is provided on the side wall of the short rod; the nozzle is disposed on the nozzle seat and extends into the spray hole; the gas channel is disposed inside the short rod; the liquid connecting pipe and the gas connecting pipe are respectively disposed on the flange; the liquid connecting pipe passes through the flange and is connected to the nozzle via the nozzle seat; the gas connecting pipe is connected to the spray hole via the gas channel.

[0013] Preferably, the nozzle seat and the shorting rod of the present invention are provided with a first gap; the spray hole and the nozzle are provided with a second gap; the inner cavity of the shorting rod, the first gap and the second gap together form a gas channel; the gas connecting pipe is connected to the spray hole through the inner cavity of the shorting rod, the first gap and the second gap.

[0014] Preferably, the first and second gaps used in this invention are both annular in structure.

[0015] Preferably, the nozzle used in this invention is arranged radially on the nozzle seat and extends into the spray hole.

[0016] Preferably, the present invention uses multiple nozzles, which are evenly distributed along the radial direction of the nozzle seat.

[0017] Preferably, the number of nozzles used in this invention is even.

[0018] Preferably, the in-situ direct-push injection drill tool for repair agents provided by the present invention further includes a drill rod and a striking cap; the drill rod is threadedly connected to a shorting rod; the liquid connecting pipe passes through the striking cap and extends along the axial direction of the drill rod and is connected to the nozzle; the gas connecting pipe passes through the striking cap and extends along the axial direction of the drill rod and is connected to the gas channel.

[0019] Preferably, the drill rod used in this invention is multi-sectioned, and the multi-sectioned drill rod is connected from front to back by threads.

[0020] Preferably, the liquid hose used in this invention is provided with a liquid medium mixing device at its end. The liquid medium mixing device includes a drug inlet, a first one-way valve, a second one-way valve, a water inlet, and a three-way valve. The drug inlet is connected to the three-way valve through the second one-way valve. The water inlet is connected to the three-way valve through the first one-way valve. The three-way valve is connected to the liquid hose.

[0021] Preferably, the gas hose used in this invention has a gas inlet at its end; the gas inlet is used to introduce air or nitrogen.

[0022] A method for enhancing in-situ direct-thrust injection of repair agents based on the repair agent-enhanced in-situ direct-thrust injection drill string as described above, characterized in that: the method includes the following steps:

[0023] 1) Connect the injection drill bit of the in-situ direct-push injection drilling tool with the repair agent to the direct-push drilling machine. The injection drill bit enters the predetermined depth of the underground target repair area through the direct-push drilling machine to avoid the vibration and shaking of the drill rod in the non-vertical direction during the direct-push process, and ensure that the outer wall of the drill rod is in close contact with the soil layer without gaps.

[0024] 2) Based on the formation permeability at the depth of the in-situ direct-push injection drill bit enhanced by the repair agent, a suitable injection / jet method is used to inject the repair agent injection medium into the target repair area under the envelopment and atomization effect of high-pressure airflow.

[0025] As a preferred embodiment, step 2) of the present invention is specifically implemented as follows:

[0026] For medium- and high-permeability formations, a low-pressure atomization injection method is used. The specific implementation method of the repair in step 2) is as follows: the injection medium prepared with the repair agent is injected into the target repair area through a liquid channel formed by liquid hose → liquid connecting pipe → nozzle seat → nozzle → spray hole on the short connector rod using a lower injection pressure. The lower injection pressure is recommended to be 0.5-3MPa. At the same time, high-pressure gas is used to atomize and envelop the injection medium prepared with the repair agent through a gas channel formed by gas hose → gas connecting pipe → inner cavity of the short connector rod, first gap, second gap → spray hole, thereby achieving enhanced transmission within the target repair area.

[0027] For low-permeability formations, a hydraulic fracturing-high-pressure atomization injection method is used. The specific implementation of the repair in step 2) is as follows: First, ultra-high-pressure water is injected into the target repair area through the aforementioned liquid channel to impact the low-permeability formation and form fractures, thereby improving the permeability of the low-permeability formation. This hydraulic fracturing step can use only water or a proppant (such as a water / sand mixture) to enhance the fracturing effect. The ultra-high pressure can be as high as 20 MPa or above. Subsequently, the repair agent injection medium is switched to, and the injection medium is injected into the formation with improved permeability through the same liquid channel using a lower injection pressure. The lower injection pressure is recommended to be 1-3 MPa. At the same time, high-pressure gas is used through the aforementioned gas channel to envelop and atomize the injection medium prepared with the repair agent, thereby achieving enhanced transport within the target repair area.

[0028] The advantages of this invention are:

[0029] This invention provides a repair agent-enhanced in-situ direct-push injection drill bit and injection method. The repair agent-enhanced in-situ direct-push injection drill bit includes an injection drill bit, which comprises a short connector, a nozzle seat, a nozzle, a drill bit, a flange, a gas channel, a liquid connecting pipe, and a gas connecting pipe. The short connector is a hollow tubular structure. The flange and the drill bit are respectively located at both ends of the short connector. The nozzle seat is located axially inside the short connector. An injection hole communicating with the interior of the short connector is provided on its side wall. The nozzle is located on the nozzle seat and extends into the injection hole. The gas channel is located inside the short connector. The liquid connecting pipe and the gas connecting pipe are respectively located on the flange. The liquid connecting pipe passes through the flange and is connected to the nozzle via the nozzle seat. The gas connecting pipe is connected to the injection hole via the gas channel. This invention integrates low-pressure atomized injection for medium- and high-permeability formations with hydraulic fracturing-atomized jetting for low-permeability formations. It boasts high mobility, convenient operation, and the injection / jet method can be adjusted according to changes in formation texture to achieve optimal reagent delivery and precise reagent transport. Compared to traditional direct injection, it adds airflow encapsulation and atomization functions for reagent injection in medium- and high-permeability formations. The hydraulic fracturing-atomized jetting method enables adaptability to low-permeability formations. Compared to high-pressure rotary jetting, it offers superior reagent delivery and a larger radius of influence for low-permeability formations, allowing for different depths within the target repair area. The location allows for optimized adjustment of injection methods and volumes based on different geological conditions and pollution distribution characteristics, achieving precise injection. It avoids the drawbacks of large, cumbersome, and poorly maneuverable high-pressure jet grouting equipment, making it difficult to operate in complex conditions and terrains. Compared to hydraulic and pneumatic fracturing technologies, this invention achieves similar results but avoids the need for pre-drilling, casing installation, and the use of double packers, as well as the difficulty in obtaining certain specialized equipment, making this technology more direct, faster, more efficient, and lower-cost. The applicability of this invention to medium-to-high permeability formations is also not found in hydraulic or pneumatic fracturing. The remediation agents provided by this invention enhance the connection and operation of in-situ direct-push injection drill bits and tools with matching direct-push drilling rigs and auxiliary equipment (including water pumps, chemical pumps, air compressors, and chemical mixing tanks), enabling the implementation of in-situ remediation technologies for contaminated soil and groundwater in the field of environmental remediation. This enhances the delivery of remediation agents (aqueous solutions, diluted mud, suspensions, emulsions, etc.) within the target underground remediation area. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall structure of the in-situ direct-push injection drilling tool (including drill rod and hose) provided by the present invention, which is a repair agent enhanced by the present invention.

[0031] Figure 2 This is a schematic diagram of the overall structure of the in-situ direct-push injection drill bit reinforced with repair agent provided by the present invention;

[0032] Figure 3 yes Figure 2 AA view;

[0033] Figure 4 This is a top view of the flange structure used in this invention;

[0034] Figure 5 yes Figure 4 AA view;

[0035] Figure 6 This is a schematic diagram of the shorting rod used in this invention;

[0036] Figure 7 yes Figure 6 AA view;

[0037] Figure 8 This is a schematic diagram of the nozzle seat used in this invention;

[0038] Figure 9 yes Figure 8 AA view;

[0039] Figure 10 This is a schematic diagram of the nozzle structure used in this invention;

[0040] Figure 11 yes Figure 10 AA view;

[0041] Figure 12 This is a schematic diagram of the drill bit used in this invention;

[0042] Figure 13 yes Figure 12 AA view;

[0043] Figure 14 This is a schematic diagram of the drill rod structure used in this invention;

[0044] Figure 15 yes Figure 14 AA view;

[0045] in:

[0046] 1-Liquid connection pipe; 2-Gas connection pipe; 3-Flange; 4-Short rod; 5-Nozzle seat; 6-Nozzle; 7-Drill bit; 8-Drill rod; 9-Knock cap; 10-Gas inlet; 11-Reagent inlet; 12-Water inlet; 13-First check valve; 14-Second check valve; 15-Tee. Detailed Implementation

[0047] This invention is a core component of an in-situ enhanced delivery technology for repair agents that integrates traditional direct-push technology with elements of hydraulic fracturing and pneumatic fracturing. Specifically, it relates to a dual-channel / dual-inner-tube in-situ direct-push injection drill string and injection method for enhanced repair agents, aiming to solve several challenging problems in in-situ agent delivery:

[0048] 1) Traditional direct injection technology, which is suitable for low-pressure injection in medium and high permeability formations, has an impact radius difference in low-permeability sites;

[0049] 2) High-pressure rotary jet spraying improves the delivery of chemicals, but its radius of influence is still poor in low-permeability areas. In addition, the equipment is large and heavy, with poor mobility, lack of targeted chemical injection, easy waste, and easy to cause disturbance and migration of pollutants.

[0050] 3) Fracturing technology requires drilling and casing installation, which requires specialized equipment (such as double packer injection rods) that is difficult to obtain, involves many steps, is time-consuming, and has high costs.

[0051] Based on this, the innovation of this invention lies in: a dual-inner-tube structure, one for liquid media and one for gas; water and various pharmaceutical injections / media share the same liquid tube; air, nitrogen, or other gases use the gas tube; this dual-inner-tube structure facilitates controlling the outer diameter of the drill rod 8 and the drill bit to a reasonable size (e.g., around 10cm or less), as an excessively large outer diameter will lead to difficulties in direct thrust; the drill bit, including the flange 3 on the upper end face, the long curved liquid connecting pipe 1, and the short straight gas connecting pipe 2, completely separates the gas and liquid paths within the drill bit cavity, ultimately ejecting the two media from the nozzle 6 and the annular gap between the nozzle 6 and the nozzle hole respectively; this invention is compatible with needle... For low-pressure direct-push injection in medium- and high-permeability formations, this system incorporates airflow encapsulation and atomization functions, as well as hydraulic fracturing-high-pressure atomized jetting for low-permeability formations. This allows a single device to meet the in-situ agent delivery needs of formations with varying permeability, facilitating precise agent injection. The fracturing and atomized jetting functions, enhanced by direct-push technology, combine the lightweight and highly mobile equipment of traditional direct-push injection with the enhanced agent delivery capabilities of hydraulic and pneumatic fracturing in low-permeability formations. This offers advantages such as directness, speed, and adaptability to formations with varying permeability, eliminating the drawbacks and cumbersome procedures of high-pressure rotary jetting and fracturing technologies. When the design and manufacturing process of the check valve allows its outer diameter to be approximately the same as the pipe diameter, the check valve can be installed inside the first drill pipe section 8, near the flange 3 on the upper end of the drill string, thus better preventing backflow of media in the hoses or cross-contamination between different media.

[0052] The technical solution provided by the invention will now be described in detail with reference to the accompanying drawings:

[0053] See Figure 2 as well as Figure 3This invention provides a repair agent-enhanced in-situ direct-push injection drill bit, comprising a short connector 4, a nozzle seat 5, a nozzle 6, and a drill bit 7 (the structure of which is as follows). Figure 12 as well as Figure 13 (As shown), flange 3, liquid connection pipe 1, and gas connection pipe 2; see also Figure 6 as well as Figure 7 The shorting rod 4 has a hollow tubular structure; the flange 3 and the drill bit 7 are respectively located at both ends of the shorting rod 4; see [link / reference]. Figure 8 as well as Figure 9 The nozzle seat 5 is arranged axially inside the shorting rod 4; a spray hole communicating with the interior of the shorting rod 4 is provided on the side wall of the shorting rod 4; see also Figure 10 as well as Figure 11 Nozzle 6 is mounted on nozzle seat 5 and extends into the nozzle orifice; gas passage is located inside short rod 4; see also Figure 4 as well as Figure 5 The flange 3 has two through holes, into which the liquid connection pipe and the gas connection pipe are respectively embedded and pass through the flange 3. These two connection pipes are connected to the liquid hose 1 and the gas hose 2 respectively through joints on the outside of the flange 3. The long curved liquid connection pipe is threaded to the center hole of the nozzle seat 5 inside the flange 3 and the drill tool cavity. One end of the short straight gas connection pipe is exposed inside the drill tool cavity on the inside of the flange 3. After passing through the flange 3, the liquid connection pipe is connected to the nozzle 6 through the nozzle seat 5. The gas connection pipe is connected to the nozzle hole through the gas channel.

[0054] A first annular gap is provided between the nozzle seat 5 and the shorting rod 4; a second annular gap is provided between the spray hole and the nozzle 6; the inner cavity of the shorting rod 4, the first gap and the second gap together form a gas channel; the gas connecting pipe is connected to the spray hole through the inner cavity of the shorting rod 4, the first gap and the second gap.

[0055] Nozzles 6 are radially disposed on nozzle seat 5 and extend into the nozzle orifice. Multiple nozzles 6 are evenly distributed radially along nozzle seat 5; preferably, there is an even number of nozzles 6. The nozzles 6 are fixed to nozzle seat 5 and uniformly arranged in the same cross-section, preferably an even number, such as four (alternating at 90° intervals). The shorting rod 4 has an opening (nozzle) at a position corresponding to the nozzle 6, with the opening diameter slightly larger than the nozzle 6 diameter. The annular space between the outer wall of nozzle seat 5 and the inner wall of shorting rod 4, and the annular space between the nozzle 6 and the nozzle orifice, serve as gas channels through which gas enters the formation.

[0056] Furthermore, the repair agent-enhanced in-situ direct-push injection drilling tool provided by this invention also includes a drill pipe 8 (the structure of which is as follows) Figure 14 as well as Figure 15As shown), the drill pipe consists of a liquid hose 1, a gas hose 2, and a striking cap 9; the drill pipe 8 is threadedly connected to the injection drill bit; the liquid hose 1 passes through the striking cap 9 and extends axially through the drill pipe 8, connecting to the liquid connection pipe of the injection drill bit; the gas hose 2 passes through the striking cap 9 and extends axially through the drill pipe 8, connecting to the gas connection pipe of the injection drill bit. The striking cap 9 is threadedly connected to the drill pipe 8.

[0057] The drill rod 8 is multi-sectioned, and the multi-sectioned drill rod 8 is connected from front to back by threads. The length of the drill rod 8 is generally 1-1.5 meters per section.

[0058] See Figure 1 The upstream end of the liquid hose 1 is connected to a liquid medium (water and various pharmaceutical injection solutions / mediums) mixing device. The liquid medium mixing device includes a pharmaceutical inlet 11, a first check valve 13 (which can also be a shut-off valve, for example, a high-pressure ball valve), a second check valve 14 (which can also be a shut-off valve, for example, a high-pressure ball valve), a water inlet 12, and a three-way valve 15. The pharmaceutical inlet 11 is connected to the three-way valve 15 through the second check valve 14; the water inlet 12 is connected to the three-way valve 15 through the first check valve 13; and the three-way valve 15 is connected to the liquid hose 1. The end of the gas hose 2 is provided with a gas inlet 10; air or nitrogen is introduced through the gas inlet 10. The liquid hose 1 is divided into two paths: one for water and the other for a repair agent injection solution (which can be an aqueous solution, suspension, or diluted mud). Each path is equipped with a shut-off valve (such as a high-pressure ball valve) or a check valve. When the design and manufacturing process of the check valve allows the outer diameter of the valve to be basically consistent with the pipe diameter, the check valve can be installed inside the first section of drill pipe 8, at the end of the connection pipe between the liquid hose 1 and the gas hose 2 and the flange 3 that penetrates the upper end face of the drill bit. This better prevents the backflow of the medium in each hose or the cross-contamination between different media.

[0059] The material of the liquid hose 1 should have properties such as wear resistance, impact resistance, corrosion resistance, self-lubrication, shock energy absorption, and good non-stick properties, such as ultra-high molecular weight polyethylene (UPE); the drill bit material should have excellent corrosion resistance and high temperature strength, and can be used under harsh conditions, such as 316 stainless steel.

[0060] The working process of this invention is as follows:

[0061] This dual-channel / dual-inner-tube in-situ direct-push injection drill bit for enhanced repair agents has one inner tube that delivers liquid (water, various forms of injection medium) and the other inner tube that delivers high-pressure gas (usually air, but can also be nitrogen, used for delivering reducing or anaerobic agents). This drill bit is connected to and operates with a direct-push drilling rig and auxiliary equipment (including water pump, injection pump, air compressor, dosing tank, etc.). The drill bit is directly pushed into the predetermined depth of the target repair area underground. The outer wall of the drill bit and drill rod 8 is tightly fitted with the soil layer to prevent the injected medium from rising along the drill bit and drill rod 8 and leaking out to the ground through the gap between the drill bit and the soil layer.

[0062] Depending on the permeability of the formation at the depth where the drilling tool is located, if it is a medium to high permeability formation, a lower injection pressure should be used to directly inject the injection medium prepared with the repair agent into the target repair area. After being pressurized by the injection pump, the liquid injection medium passes through the liquid branch pipe → tee 15 → liquid main pipe → liquid connection pipe 1 on the drilling tool flange 3 → the inner cavity of the nozzle seat 5 → nozzle 6, and is finally injected into the soil layer.

[0063] This dual-inner-tube drill bit, based on traditional direct-push injection, enhances the high-pressure liquid medium jet by enveloping and atomizing it with a high-pressure airflow. This protects the pressure of the high-pressure liquid jet, constrains its outward divergence and attenuation, facilitating a larger injection radius and promoting uniform distribution of the liquid medium within the injection area. The high-pressure airflow comes from an air compressor (air), while nitrogen can be directly supplied from a gas cylinder, flowing through a gas hose → gas connection pipe 2 on the drill bit flange 3 → drill bit inner cavity → and exiting through the annular gap between the nozzle 6 and the spray hole.

[0064] For low-permeability formations, such as silt and clay layers, a combined hydraulic fracturing and high-pressure atomized injection technique is employed to enhance permeability. First, ultra-high pressure water (e.g., 20 MPa or higher) is used to open fractures in the low-permeability soil layer, increasing its permeability. This hydraulic fracturing step can utilize proppant (optional). Then, the process switches to a chemical injection medium, which, under lower pressure (e.g., 1-3 MPa), is injected into the soil layer under the atomization effect of a high-pressure airflow, achieving enhanced chemical delivery within the target repair area.

[0065] Whether it's low-pressure atomized injection for medium- and high-permeability formations or hydraulic fracturing-high-pressure atomized jetting for permeable formations, both are based on direct-push technology, eliminating the need for drilling, casing installation, or double packers. After injection at each depth, the drill string is withdrawn (from bottom to top) or advanced (from top to bottom) by 0.5-1m before injection again. A 0.5-1m injection interval is recommended. The injection / jet method and specific operating parameters (injection pressure, injection speed, injection volume, etc.) can be adjusted at any time according to formation changes, achieving precise injection of the agent into the target repair area and obtaining the ideal influence range and radius.

Claims

1. A remedial agent augmented in-situ direct push jetting drill, characterized by: The repair agent reinforced in-situ direct push jetting drill tool comprises a short connecting rod (4), a nozzle seat (5), a nozzle (6), a drill bit (7), a flange plate (3), a gas channel, a liquid connecting pipe (1) and a gas connecting pipe (2); the short connecting rod (4) is in a hollow tubular structure as a whole; the flange plate (3) and the drill bit (7) are respectively arranged at two ends of the short connecting rod (4); the nozzle seat (5) is arranged in the inside of the short connecting rod (4) along the axial direction of the short connecting rod (4); a spray hole penetrating through the inside of the short connecting rod (4) is arranged on the side wall of the short connecting rod (4); the nozzle (6) is arranged on the nozzle seat (5) and extends into the spray hole; the gas channel is arranged in the inside of the short connecting rod (4); the liquid connecting pipe and the gas connecting pipe are respectively arranged on the flange plate (3); the liquid connecting pipe is connected with the nozzle (6) through the nozzle seat (5) after penetrating through the flange plate (3); the gas connecting pipe is connected with the spray hole through the gas channel; a first gap is arranged between the nozzle seat (5) and the short connecting rod (4); a second gap is arranged between the spray hole and the nozzle (6); the inside of the short connecting rod (4), the first gap and the second gap jointly form the gas channel; the gas connecting pipe is connected with the spray hole through the inside of the short connecting rod (4), the first gap and the second gap; the structures of the first gap and the second gap are annular; the upstream end of the liquid connecting pipe (1) is provided with a liquid medium mixing device, which comprises a medicament inlet (11), a first one-way valve (13), a second one-way valve (14), a water inlet (12) and a three-way pipe (15); the medicament inlet (11) is connected with the three-way pipe (15) through the second one-way valve (14); the water inlet (12) is connected with the three-way pipe (15) through the first one-way valve (13); the three-way pipe (15) is connected with the liquid connecting pipe (1).

2. The remedial agent augmented in-situ direct-pushing jetting drill tool of claim 1, wherein: The nozzle (6) is arranged on the nozzle seat (5) along the radial direction of the nozzle seat (5) and extends into the spray hole.

3. The remedial agent augmented in-situ direct-pushing jetting drill tool of claim 2, wherein: The nozzle (6) is a plurality of nozzles (6) which are arranged in a uniform distribution along the radial direction of the nozzle seat (5).

4. The remedial fluid enhanced in situ direct push jetting drill tool of claim 1 or 2 or 3, wherein: The repair agent reinforced in-situ direct push jetting drill tool further comprises a drill rod (8) and a knocking cap (9); the drill rod (8) is threadedly connected with the short connecting rod (4); the liquid connecting pipe (1) is connected with the nozzle (6) after penetrating through the drill rod (8) along the axial direction of the drill rod (8) through the knocking cap (9); the gas connecting pipe (2) is connected with the gas channel after penetrating through the drill rod (8) along the axial direction of the drill rod (8) through the knocking cap (9).

5. The remedial agent augmented in-situ direct-pushing jetting drill tool of claim 4, wherein: The drill rod (8) is a plurality of sections which are connected through threads from front to back.

6. The remedial agent augmented in-situ direct-pushing jetting drill tool of claim 5, wherein: The upstream end of the gas connecting pipe (2) is provided with a gas inlet (10); the gas inlet (10) is connected with air or nitrogen.

7. A method of repairing a downhole jetting tool with a repair agent enhanced downhole jetting tool based on any one of claims 1-6, wherein: The method comprises the following steps: 1) connecting the jetting drill tool, the drill rod and the direct push drill machine of the repair agent reinforced in-situ direct push jetting drill tool according to any one of claims 1-6; the jetting drill tool enters the predetermined depth of the underground target repair area through the direct push drill machine, and ensures that the outer wall of the drill rod (8) is tightly attached to the soil layer without gap; 2) According to the permeability of the formation at the depth position of the repaired drilling tool, the injection medium of the repair agent is injected into the target repair area under the wrapping and atomization of high-pressure gas flow; The specific implementation of step 2) is: For medium and high permeability formations, the specific implementation of the repair in step 2) is: the injection medium of the repair agent is injected into the target repair area through the liquid hose, the liquid connecting pipe (1), the nozzle seat (5), the nozzle (6) and the injection hole on the short connecting rod (4) under a lower injection pressure, and the lower injection pressure is 0.5-3MPa; at the same time, the high-pressure gas passes through the gas channel in the inner cavity of the short connecting rod (4), and finally reaches the injection hole, so as to wrap and atomize the injection medium of the repair agent by high-pressure gas flow, and realize the strengthened transmission in the target repair area; For low permeability formations, the specific implementation of the repair in step 2) is: first, the water flow with ultrahigh pressure is injected into the target repair area through the liquid channel, so as to impact the low permeability formation and form a fracture, and improve the permeability of the low permeability formation, and the ultrahigh pressure is not less than 20MPa; then, the injection medium of the repair agent is switched, and the injection medium is injected into the formation with improved permeability through the liquid channel under a lower injection pressure, so as to repair the target repair area, and the lower injection pressure is 1-3MPa; at the same time, the high-pressure gas passes through the aforementioned gas channel, so as to wrap and atomize the injection medium of the repair agent by high-pressure gas flow, and realize the strengthened transmission in the target repair area.

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