Drilling tool for sludge sampling

Abstract

The drilling tool comprises a drill bit, the drill bit is provided with a cylindrical shell, the bottom edge of the cylindrical shell is fixedly connected with a plurality of diamond drill bits, the top of the cylindrical shell is narrowed inwards and provided with a connecting part, and the connecting part is used for being connected with a drilling machine. A plurality of spiral sheets are uniformly arranged in the drill bit and are matched to form a continuous spiral flow guide channel, the disturbance is low, specifically, the spiral iron sheet is segmented, the shearing force to sludge during rotation is reduced by 40%-60%, and the layering definition of a sample is improved; rapid preparation is achieved, drilling tool assembly can be completed within 2 hours through a standardized welding assembly, and the cost is extremely low; the spiral design is beneficial to continuous sampling of samples and can prevent the samples from slipping off in the lifting process; environmental adaptability: the device is highly adaptive to a drilling tool, and is at least suitable for rivers, lakes, reservoirs and the like with the water depth of 30 m or less and the sludge thickness of 20 m at present through actual operation.

Description

Technical Field

[0001] This utility model relates to the field of geological exploration technology, and in particular to a drilling tool for silt sampling. Background Technology

[0002] In the field of geological exploration, it is usually necessary to sample silt layers with high water content and low bearing capacity, including collecting undisturbed silt samples in complex environments such as reservoirs, rivers, lakes, coastal zones and soft soil foundations.

[0003] Silt in river and lake basins is characterized by high water content (usually >50%) and low bearing capacity. Traditional sampling methods face the following challenges: First, they are sensitive to disturbance: the rotating cutting of the drill bit can easily damage the original structure of the silt layer, leading to a decrease in sample representativeness. Second, the equipment is bulky: existing riverbed sampling drills mostly use complex sealing or hydraulic drive systems, which are costly to manufacture and difficult to deploy flexibly in narrow river channels. Third, they lack applicability: drill bits designed for hard soils (such as fish-tail drills and spoon drills) are prone to clogging in silt, and thin-walled samplers are easily deflected by water flow impact when inserted. Therefore, a riverbed-specific drill tool with a simple structure, low cost, and the ability to balance sampling efficiency and sample fidelity is needed. Utility Model Content

[0004] This utility model patent aims to address the shortcomings of the prior art by providing a drilling tool for silt sampling, thereby solving the technical problems of the prior art, such as the easy damage to the original structure of the silt layer caused by the rotating cutting of the drill bit, the bulky sampling drill, and the easy clogging of the drill bit.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is: a drill bit for silt sampling, including a drill bit, the drill bit having a cylindrical shell, a plurality of diamond drill bits fixedly connected to the bottom edge of the cylindrical shell, the top of the cylindrical shell narrowing inward and having a connecting part, the connecting part being used to connect to a drilling machine, and a plurality of spiral blades uniformly arranged inside the drill bit, the plurality of spiral blades cooperating to form a continuous spiral guide channel.

[0006] Preferably, the connecting part is a hollow cylinder with external threads on its outer wall, and is connected to the drilling rig threadedly through the external threads.

[0007] Preferably, the plurality of spiral blades are uniformly welded in three groups to the inner wall of the drill bit.

[0008] Preferably, the inner wall of the drill bit is also coated with an anti-stick coating.

[0009] Preferably, the spiral blade is made of stainless steel.

[0010] Preferably, the spiral blades are 2 mm thick and the blade spacing is 0.4 times the inner diameter of the drill bit.

[0011] Preferably, the welding angle of the spiral blade is set to 20°.

[0012] Preferably, the anti-stick coating is polytetrafluoroethylene.

[0013] The beneficial effects of this utility model are:

[0014] Low disturbance: The segmented spiral iron plate reduces the shear force on the silt by 40%-60% during rotation, improving the clarity of sample stratification; Rapid preparation: Standardized welding components can complete drill assembly within 2 hours, with extremely low cost; Strong anti-interference: The spiral design facilitates continuous sample collection and prevents sample slippage during lifting; Environmental adaptability: It has strong compatibility with drill tools, and through actual operation, it is currently applicable to rivers, lakes, and reservoirs with a water depth of at least 30m and a silt thickness of 20m. Attached Figure Description

[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0016] Figure 1 This is a schematic diagram of the structure of this utility model;

[0017] In the diagram: 1. Connecting part; 2. Drill bit; 3. Diamond drill bit; 4. Spiral blade; 5. Anti-stick coating; Detailed Implementation

[0018] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0019] like Figure 1 As shown, a drilling tool for silt sampling includes a drill bit 2. The drill bit 2 has a cylindrical shell, and several diamond drill bits 3 are fixedly connected to the bottom edge of the cylindrical shell. The top of the cylindrical shell narrows inward and is provided with a connecting part 1, which is used to connect to a drilling rig. Several spiral blades 4 are uniformly arranged inside the drill bit 2. The spiral blades 4 cooperate to form a continuous spiral guide channel. In this embodiment, the outer shell of the drill bit 2 is cylindrical, and several diamond drill bits 3 are fixedly connected to the bottom edge of the drill bit 2. During operation, the drilling rig drives the drill bit to rotate into the riverbed at a speed of 60-80 r / min. The spiral blades continuously push the silt sample upward along the guide channel, while a negative pressure adsorption effect is formed in the inner cavity of the drill bit.

[0020] Preferably, the connecting part 1 is a hollow cylinder with an external thread on its outer wall, which is connected to the drilling rig thread through the external thread and fixedly connected by the external thread and the drilling rig thread.

[0021] Preferably, the plurality of spiral blades 4 are three groups uniformly welded to the inner wall of the drill bit 2, and at least two groups of spiral guide iron plates are welded to the inner wall circumferentially. In this embodiment, three groups are preferred. The segmented spiral iron plates reduce the shear force on the silt by 40%-60% when rotating, and improve the clarity of sample layering.

[0022] Preferably, the inner wall of the drill bit 2 is also coated with an anti-stick coating 5. In this embodiment, the inner wall of the drill bit tube may be provided with an anti-stick coating. This drill is particularly suitable for sampling fluid plastic sludge with a water content of more than 60%, and the sampling integrity rate can reach more than 90%, and it can effectively maintain the original structure and layered characteristics of the sample.

[0023] Preferably, the spiral blade 4 is made of stainless steel, which prevents the steel blade from rusting and affecting the soil quality during long-term use.

[0024] Preferably, the spiral blade 4 has a thickness of 2mm and the blade spacing is 0.4 times the inner diameter of the drill bit. In this embodiment, a diamond composite drill bit is selected as the body (inner diameter 50-80mm), and 2-3 sets of spiral guide iron plates are uniformly welded to its inner wall (preferably three sets). The iron plate thickness is 2mm and the blade spacing is 0.4 times the inner diameter of the drill bit (for example, when the inner diameter is 60mm, the spacing is 24mm). This blade spacing results in better performance of the drill bit 2.

[0025] Preferably, the welding angle of the spiral blade 4 is set to 20°. In this embodiment, each spiral iron blade extends axially at an angle of 15°-25° to form a continuous flow channel. The thickness of the spiral iron blade is 2-4mm, and the spacing between the blades is 0.3-0.5 times the inner diameter of the drill bit. The effect is best when the welding angle is set to 20°.

[0026] Preferably, the anti-stick coating 5 is polytetrafluoroethylene (PTFE), which has the characteristics of high temperature resistance and extremely low coefficient of friction.

[0027] The specific working method of this application is as follows: Step 1: Drill string assembly

[0028] 1.1 Select a diamond composite drill bit as the body (inner diameter 50-80mm), and uniformly weld 2-3 sets of spiral guide iron plates around its inner wall; the thickness of the iron plates is 2mm, the spacing between the plates is 0.4 times the inner diameter of the drill bit (for example, when the inner diameter is 60mm, the spacing is 24mm), and the welding angle is set to 20° to form a continuous spiral guide channel.

[0029] 1.2 Connect the drill bit tail to the drill bit tool (1.2m in length; if necessary, a polytetrafluoroethylene anti-stick coating can be sprayed on the inner wall).

[0030] Step 2: Drilling and Sampling

[0031] 2.1 First, lower the casing to the designated sampling position using the drilling rig. Then, vertically align the assembled drill bit with the sampling point on the riverbed, adjust the rotation speed to 60 r / min, and slowly apply pressure to screw it into the silt layer.

[0032] 2.2 The spiral guide iron plate pushes the cut sludge upward along the guide channel, while the inner cavity of the drill bit generates negative pressure due to the spiral motion, which adsorbs the loose sludge and enters the drill bit;

[0033] Step 3: Sample Recovery and Processing

[0034] 3.1 Once the drilling depth reaches the preset value (1.0-1.5m), stop drilling and let it stand for 1-2 minutes;

[0035] 3.2 Reverse the drilling rig to withdraw the drill string and slowly push the silt sample into the sampling container;

[0036] 3.3 Rinse the inner wall of the sample tube with a high-pressure water gun (5MPa) to remove any residue. The anti-stick coating ensures that no sample residue remains.

[0037] The above embodiments are only used to illustrate the technical methods of this utility model and are not intended to limit it. Those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical methods of this utility model without departing from the spirit and scope of the technical methods of this utility model.

[0038] Application Example: The drilling tool described in this invention was successfully applied to a dredging project of a medium-sized reservoir with a capacity of 30 million m³, completing deep silt sampling operations under complex aquatic conditions. In a specific implementation case, the water depth in the operating area was 26 m, and the underwater silt layer exhibited a typical fluid-plastic state (water content 68-73%), with a layer thickness of 20-30 m and containing gravel and rock interlayers. By configuring this device, continuous 22 m full-section sampling was achieved at a rotation speed of 60 r / min. Testing revealed: ① The positioning error of each section of the sampling tube was ≤0.15 m, accurately marking each layer interface; ② The structural fidelity of the obtained columnar sample reached 94.7%. This implementation case demonstrates that this device can effectively maintain the in-situ physical state of silt even under deep-water and high-pressure environments, making it particularly suitable for the refined investigation of silt deposits in front of dams in hydropower projects.

[0039] The above embodiments are merely preferred technical solutions of this utility model and should not be considered as limitations on this utility model. The protection scope of this utility model should be the technical solution described in the claims, including equivalent substitutions of the technical features described in the claims. That is, equivalent substitutions and improvements within this scope are also within the protection scope of this utility model.

Claims

1. A drilling tool for silt sampling, characterized in that, Includes a drill bit (2), the drill bit (2) has a cylindrical shell, a plurality of diamond drill bits (3) are fixedly connected to the bottom edge of the cylindrical shell, the top of the cylindrical shell is narrowed inward and provided with a connecting part (1), the connecting part (1) is used to connect to the drilling machine, and a plurality of spiral blades (4) are uniformly arranged inside the drill bit (2), the plurality of spiral blades (4) cooperate to form a continuous spiral guide channel.

2. A drill tool for sludge sampling according to claim 1, characterised in that: The connecting part (1) is a hollow cylinder with external threads on its outer wall, and is connected to the drilling rig thread through the external threads.

3. The drill tool for sludge sampling of claim 1, wherein: The spiral blades (4) are welded in three groups evenly to the inner wall of the drill bit (2).

4. A drill tool for sludge sampling according to claim 3, characterised in that: The inner wall of the drill bit (2) is also coated with an anti-stick coating (5).

5. The drill tool for sludge sampling of claim 1, wherein: The spiral blade (4) is made of stainless steel.

6. A drill tool for sludge sampling according to claim 5, characterised in that: The spiral blade (4) has a thickness of 2 mm and the blade spacing is 0.4 times the inner diameter of the drill bit.

7. A drill tool for sludge sampling according to claim 5, characterised in that: The welding angle of the spiral blade (4) is set to 20°.

8. The drill tool for sludge sampling of claim 4, wherein: The anti-stick coating (5) is polytetrafluoroethylene.

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