A coring bit suitable for use in soft and hard loose formations

Abstract

The utility model discloses a kind of core drill bits suitable for loose rock layer of soft and hard, it is related to drill bit technical field, including the drill bit carcass of cylindrical, the inner edge of drill bit carcass top extends upwards and forms a circle of baffle;Drill bit carcass is one step of low outside and high inside on the outside of baffle;Drill bit carcass top is equipped with a plurality of drill teeth on the outside of baffle, and the height of drill tooth is higher than baffle;Several water outlet channels that pass through drill bit carcass are equipped on the low layer step between two adjacent drill teeth;Drill bit carcass top step design, so that in the drilling process, the drill cuttings accumulated on high step are double blocked with baffle to drilling fluid, avoid direct scouring of drilling fluid to core, improve coring efficiency.

Description

Technical Field

[0001] This utility model relates to the field of drill bit technology, specifically a core drilling bit suitable for loose rock formations of varying hardness. Background Technology

[0002] The loose rock strata consist of Quaternary, Neogene, and Paleogene strata, mainly composed of clay, sand, gravel, and loosely cemented rocks. The rock strata vary in hardness, with softer strata including common clay and common sand, and harder strata including calcareous clay, sandstone, and gravel. During the construction of inspection boreholes in coal mine shafts and bedrock marker boreholes for ground settlement monitoring, full coring operations are required in the loose rock strata above the intact bedrock, with a high requirement for core sampling rate.

[0003] Currently, the single / double tube coring method with drilling fluid circulation is commonly used in geological coring operations. This method is highly effective when coring bedrock. However, when coring in loosely cemented rock formations (especially sand layers), the drilling fluid spraying out from the drill bit can easily cause direct erosion of the loose rock core that is about to enter the drill bit opening. This can cause the loose rock core to be broken up, resulting in a low coring rate, or even situations where ordinary coring drill bits cannot retrieve the rock core.

[0004] Based on this, the present invention aims to provide a core drilling bit suitable for loose rock formations of varying hardness, avoiding direct erosion of the rock core by drilling fluid and improving the efficiency of core drilling. Utility Model Content

[0005] To overcome the shortcomings of existing technologies, the purpose of this utility model is to provide a core drilling bit suitable for loose rock formations of varying hardness. The step-type design at the top of the drill bit body allows the rock cuttings accumulated on the higher steps and the baffles to form a double barrier against the drilling fluid during drilling, preventing the drilling fluid from directly eroding the rock core and improving core drilling efficiency.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] A core drilling bit suitable for loose rock formations of varying hardness includes a cylindrical drill bit body. The inner edge of the top of the drill bit body extends upward to form a ring-shaped baffle. The drill bit body is stepped outside the baffle, with the outer edge lower than the inner edge. Several drill teeth are provided at the top of the drill bit body outside the baffle, with the height of the drill teeth higher than the baffle. Several water outlet channels penetrating the drill bit body are provided on the lower step between two adjacent drill teeth.

[0008] In this invention, the number of water outlet channels between two adjacent drill teeth is set according to the size requirements of the drill bit, and several water outlet channels between two adjacent drill teeth are evenly distributed circumferentially.

[0009] In this utility model, the drill bit includes a tooth fixing block, wherein one half of the tooth fixing block has a set of tooth plates on its top, and the other half of the tooth fixing block has a set of tooth plates on one side of the drill bit body tangentially. The side tooth plates are located in the same clockwise direction, and the tooth plates fixed to the top of the fixing block and the tooth plates fixed to the side of the fixing block are distributed at intervals.

[0010] In this invention, the toothed plates disposed on the top of the toothed plate fixing block are alloy teeth, and the toothed plates disposed on the top of the toothed plate fixing block are composite teeth; the number of drill teeth is not less than 4, and each group of toothed plates has not less than 2 teeth. The drill teeth are evenly distributed circumferentially.

[0011] In this invention, the toothed plates located on the top of the fixed block and the toothed plates located on the side wall of the fixed block are both radially distributed along the drill bit body.

[0012] Compared with the prior art, the beneficial effects of this utility model are:

[0013] 1. In this utility model, the top of the drill bit body is a stepped shape with a lower outer edge and a higher inner edge. The water outlet channel is located on the lower step. During drilling, the rock cuttings and baffles on the upper step form a double barrier against the drilling fluid, preventing the drilling fluid from directly scouring the rock core, avoiding the loose rock core from being broken up, and improving the core extraction efficiency.

[0014] 2. The drill teeth of this utility model are respectively inlaid with composite blade teeth and alloy blade teeth. The drill teeth inlaid with composite blade teeth and alloy blade teeth are distributed at intervals. This method of inlaying two types of blade teeth at intervals can solve the problem of high cost caused by inlaying all composite blade teeth while taking into account the efficiency of core drilling. It can be applied to loose rock strata with varying hardness. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of this utility model.

[0016] Attached reference numerals: 1. Drill bit body; 2. Baffle; 3. Drill teeth; 3-1. Tooth plate fixing block; 3-2. Tooth plate; 4. Water outlet channel. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0018] This utility model discloses a core drilling bit suitable for loose rock formations of varying hardness, comprising a cylindrical drill bit body 1, wherein the inner edge of the top of the drill bit body 1 extends upward to form a ring-shaped baffle 2; the drill bit body is stepped outside the baffle 2 with a lower outer edge and a higher inner edge; the top of the drill bit body is provided with several drill teeth 3 outside the baffle, the height of the drill teeth 3 being higher than the baffle 2; several water outlet channels 4 penetrating the drill bit body are provided on the lower step between two adjacent drill teeth 3.

[0019] In this invention, the number of water outlet channels 4 between two adjacent drill teeth 3 is set according to the size requirement of the drill bit, and several water outlet channels 4 between two adjacent drill teeth are evenly distributed circumferentially.

[0020] In this utility model, the drill bit 3 includes a tooth plate fixing block 3-1, wherein one half of the tooth plate fixing block 3-1 is provided with a set of tooth plates 3-2 on the top, and the other half of the tooth plate fixing block is provided with a set of tooth plates 3-2 on one side of the drill bit body tangentially. The side tooth plates 3-2 are located in the same clockwise direction, and the tooth plates fixed on the top of the fixing block and the tooth plates fixed on the side of the fixing block are distributed at intervals.

[0021] In this invention, the toothed plates 3-2 disposed on the top of the toothed plate fixing block are alloy teeth, and the toothed plates 3-2 disposed on the top of the toothed plate fixing block are composite teeth; the number of drill teeth 3 is not less than 4, and each group of toothed plates 3-2 has not less than 2. The drill teeth 3 are evenly distributed circumferentially.

[0022] In this invention, the toothed plates 3-2 located on the top of the fixed block and the toothed plates 3-2 located on the side wall of the fixed block are both radially distributed along the drill bit body.

[0023] The principle of this utility model is as follows:

[0024] The drill bit is directly connected to the double-tube core extractor. It is lowered into the borehole and rotated to extract the core. The composite blades and alloy blades directly contact and grind the rock strata around the drill bit opening, forming a cylindrical core at the drill bit opening. The drilling fluid circulates through the drill pipe, the gap between the inner and outer tubes of the double-tube core extractor, the water outlet channel 4, and the annulus inside the borehole. The drilling fluid flows out from the water outlet channel 4 and is blocked by the rock cuttings accumulated on the upper step and the baffle 2. This means that the drilling fluid only cools the drill bit and carries away the rock cuttings accumulated on the upper step, but cannot directly flush the core at the drill bit opening, thus preventing the loose core from being dispersed.

[0025] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A core drilling bit suitable for loose rock formations of varying hardness, comprising a cylindrical drill bit body, characterized in that, The inner edge of the top of the drill bit body extends upward to form a baffle; the drill bit body is stepped outside the baffle, with the outer edge lower than the inner edge; the top of the drill bit body is provided with several drill teeth outside the baffle, and the height of the drill teeth is higher than the baffle; several water outlet channels penetrating the drill bit body are provided on the lower step between two adjacent drill teeth.

2. The core drilling bit according to claim 1, suitable for loose rock formations of varying hardness, is characterized in that, Several water outlet channels between two adjacent drill teeth are evenly distributed circumferentially.

3. The core drilling bit according to claim 1, suitable for loose rock formations of varying hardness, is characterized in that... The drill bit includes a tooth plate fixing block, wherein one half of the tooth plate fixing block has a set of tooth plates on its top, and the other half of the tooth plate fixing block has a set of tooth plates on one side of the drill bit body tangentially. The side tooth plates are located in the same clockwise direction, and the tooth plates fixed to the top of the fixing block and the tooth plates fixed to the side of the fixing block are distributed at intervals.

4. The core drilling bit according to claim 3, suitable for loose rock formations of varying hardness, is characterized in that, The toothed plates located on top of the toothed plate fixing block are alloy teeth, while the toothed plates located on top of the toothed plate fixing block are composite teeth.

5. The core drilling bit according to claim 3, suitable for loose rock formations of varying hardness, is characterized in that... The number of drill teeth shall not be less than 4, and each group of teeth shall not be less than 2.

6. The core drilling bit according to claim 5, suitable for loose rock formations of varying hardness, is characterized in that... The drill teeth are evenly distributed circumferentially.

7. The core drilling bit according to claim 5, suitable for loose rock formations of varying hardness, is characterized in that, The toothed plates located on the top of the fixed block and the toothed plates located on the side wall of the fixed block are both distributed radially along the drill bit body.

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