Soft formation drilling device with multi-mode switching function

Abstract

The invention is applicable to the technical field of geological drilling, and provides a soft formation drilling device with multi-mode switching, which comprises an outer pipe, a control rod, a control rod and a control rod, a heavy hammer and an anvil are installed in the valve body, a spring is connected between the anvil and the heavy hammer, the lower end of the anvil is connected with a disc spring seat, and first inclined holes are formed in the upper end and the lower end of the side wall of the anvil; the coring pipe abuts against the inner wall of the outer pipe through a sealing ring, a disc spring seat is arranged in the coring pipe, a disc spring is arranged at the bottom of the disc spring seat, a liner pipe is arranged on the lower portion of the coring pipe, a piston is installed in the liner pipe and connected with the bottom of a control rod, the bottom of an installation cavity is communicated with the liner pipe, and the bottom of the control rod is communicated with the coring pipe. And a check valve is arranged at the communication part. The device is simple in structure, convenient to operate, high in adaptability, high in sampling efficiency and capable of remarkably improving the drilling sampling quality of the soft coal seam and the soft and hard interbedding zone.

Description

Technical Field

[0001] The invention belongs to the technical field of geological drilling, and in particular relates to a soft formation drilling device with multi-mode switching. Background Art

[0002] With the continuous growth of my country's economy, energy demand has also shown a trend of continuous increase. Among the many energy resources, coal is still one of the cornerstones of my country's energy supply due to its relatively abundant reserves and relatively mature mining technology. Therefore, the exploration and development of coal resources has received unprecedented attention.

[0003] In the process of coal resource exploration, obtaining high-quality coal core samples is a crucial link. However, my country's coal occurrence conditions are extremely complex and changeable, especially the drilling and sampling of soft coal seams and soft and hard interbedded areas, which has long troubled professional and technical personnel in the field of coal exploration and has become a technical difficulty that needs to be overcome urgently.

[0004] At present, the drilling sampling technology for soft coal seams mainly includes two methods: pressure sampling and rotary cutting sampling. The pressure sampling drill uses air pressure or hydraulic pressure to push the sampling tube into the coal seam, which is suitable for drilling and sampling in soft coal seams. It has the advantages of small disturbance to the coal body and high sampling efficiency. However, when encountering harder formations, the drilling capacity of the pressure sampling drill is limited, which easily leads to sampling failure. The rotary cutting sampling drill drills into the coal seam through the rotary cutting action of the drill bit, which is suitable for drilling and sampling in harder formations. However, in soft coal seams, the rotary cutting sampling method is prone to damage to the coal core and large disturbance, and the sampling quality is difficult to guarantee. For drilling and sampling in soft and hard interbedded areas, the existing technology usually adopts the method of replacing the drill or adjusting the drilling parameters. This method is not only cumbersome to operate, but also difficult to ensure the continuity and efficiency of drilling sampling. In addition, due to the large change in the hardness of the formation in the soft and hard interbedded areas, vibration, drill jamming and other problems are prone to occur during the drilling process, which further increases the difficulty of drilling and sampling. Summary of the invention

[0005] The purpose of the embodiments of the present invention is to provide a soft formation drilling device with multi-mode switching, aiming to solve the problems raised in the above-mentioned background technology.

[0006] The embodiment of the present invention is implemented as follows: a soft formation drilling device with multi-mode switching includes an outer pipe and further includes:

[0007] A control rod, wherein the control rod is connected to the inner wall of the outer tube through a boss arranged on the upper part thereof, and a central hole and a side wall through hole are arranged on the upper part of the control rod for the drilling fluid to enter the interior of the drilling tool;

[0008] Valve body, the valve body is arranged in the outer pipe and forms an annular gap with the outer pipe. A weight and an anvil are installed inside the valve body. The weight is arranged at the upper part of the valve body, and the top of the weight is connected to a live valve above the valve body. The anvil is arranged at the lower part of the valve body, and a spring is connected between the anvil and the weight. The lower end of the anvil extends out of the valve body and is connected to a disc spring seat. First inclined holes are arranged at both the upper and lower ends of the side wall of the anvil, and the first inclined holes at both ends of the anvil are interconnected through through holes inside it;

[0009] Core barrel, the core barrel is arranged below the valve body, and the core barrel abuts against the inner wall of the outer pipe through a sealing ring sleeved on its outer wall. An installation chamber is arranged at the upper end of the core barrel. Second inclined holes are opened on the side wall of the installation chamber, and the second inclined holes are located below the sealing ring. A disc spring seat is arranged inside the installation chamber. A disc spring is arranged at the bottom of the disc spring seat, and the disc spring is connected to the core barrel. The disc spring seat will be in the upper limit position when only acted on by the elastic force of the disc spring. A liner is arranged at the lower part of the core barrel, a piston is installed in the liner, and the piston is connected to the bottom of a control rod. The bottom of the installation chamber is communicated with the liner, and a check valve is arranged at the communication part.

[0010] Further technical solution, a claw spring is further arranged at the bottom end of the core barrel.

[0011] Further technical solution, a drill bit is arranged at the bottom of the outer pipe.

[0012] Further technical solution, the check valve includes a check valve seat installed at the communication part between the installation chamber and the liner. A check valve ball is arranged on the check valve seat, and the outer diameter of the check valve ball is larger than the inner diameter of the middle hole in the check valve seat.

[0013] A soft formation drilling device with multi-mode switching provided by an embodiment of the present invention organically combines the structures of a press-in type sampling drill and a hammering type sampling drill, realizing the function of using the press-in type drilling and sampling method in soft formations and automatically switching to the hammering type sampling method when encountering hard formations. Its structure is simple, operation is convenient, adaptability is strong, sampling efficiency is high, and it can significantly improve the drilling and sampling quality in soft coal seams and areas with alternating hard and soft layers. Description of the Drawings

[0014] Figure 1 It is a schematic structural diagram of a soft formation drilling device with multi-mode switching provided by an embodiment of the present invention.

[0015] In the drawings: control rod 1; outer pipe 2; live valve 3; weight 4; valve body 5; spring 6; anvil 7; disc spring seat 8; core barrel 9; sealing ring 10; disc spring 11; 12; check valve seat 13; liner 14; piston 15; claw spring 16; drill bit 17. Detailed Embodiments

[0016] In order to make the objectives, technical solutions and advantages of the present invention more clear and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0017] The following describes the specific implementation of the present invention in detail with reference to specific embodiments.

[0018] As Figure 1 shown, a soft formation drilling device with multi-mode switching provided by an embodiment of the present invention includes an outer pipe 2, a drill bit 17 is provided at the bottom of the outer pipe 2, and further includes:

[0019] A control rod 1, the control rod 1 is connected to the inner wall of the outer pipe 2 through a boss provided on its upper part, and a central hole and side wall through holes are provided on the upper part of the control rod 1 for drilling fluid to enter the inside of the drill tool;

[0020] A valve body 5, the valve body 5 is arranged in the outer pipe 2 and forms an annular gap with the outer pipe 2. A weight 4 and an anvil 7 are installed inside the valve body 5. The weight 4 is arranged at the upper part of the valve body 5, and the top of the weight 4 is connected to a live valve 3 above the valve body 5. The anvil 7 is arranged at the lower part of the valve body 5, and a spring 6 is connected between the anvil 7 and the weight 4. The lower end of the anvil 7 extends out of the valve body 5 and is connected to a disc spring seat 8, and first inclined holes are provided at both the upper and lower ends of the side wall of the anvil 7, and the first inclined holes at both ends of the anvil 7 are communicated with each other through through holes inside it;

[0021] A core barrel 9, the core barrel 9 is arranged below the valve body 5, and the core barrel 9 is abutted against the inner wall of the outer pipe 2 through a sealing ring 10 sleeved on its outer wall. An installation chamber is provided at the upper end of the core barrel 9, a second inclined hole is opened on the side wall of the installation chamber, and the second inclined hole is located below the sealing ring 10. A disc spring seat 8 is arranged inside the installation chamber, a disc spring 11 is arranged at the bottom of the disc spring seat 8, and the disc spring 11 is connected to the core barrel 9. The disc spring seat 8 will be in the upper limit position when only acted by the elastic force of the disc spring 11. A liner 14 is arranged at the lower part of the core barrel 9, a piston 15 is installed in the liner 14, and the piston 15 is connected to the bottom of the control rod 1. A claw spring 16 is also provided at the bottom end of the core barrel 9. The bottom of the installation chamber is communicated with the liner 14, and a check valve is arranged at the communication part.

[0022] In an embodiment of the present invention, when the drilled formation is a soft formation, it is necessary to circulate drilling fluid during the drilling process to provide pressure for the drill tool. The drilling fluid enters the inside of the drill tool through the central hole and the side wall through hole at the upper part of the control rod 1. The drilling fluid then enters the annular gap between the core barrel 9 and the anvil 7 through the annular gap between the valve body 5 and the outer tube 2, and enters the inside of the valve body 5 through the first inclined hole on the anvil 7. At this time, the drilling fluid pressure inside the valve body 5 causes the weight 4 to bear the same pressure up and down, so the weight 4 does not move at this time. Due to the action of the sealing ring 10, the annular gap between the valve body 5 and the outer tube 2 is blocked, and the drilling fluid cannot pass through. Under the action of the drilling fluid pressure, the core barrel 9 is pushed downward. The core barrel 9 drives the disc spring seat 8 downward, the disc spring seat 8 drives the anvil 7 downward, the anvil 7 drives the valve body 5 downward, the valve body 5 drives the weight 4 downward, and the live valve 3 moves downward along the control rod 1 together with the weight 4 under the action of its own weight and the drilling fluid pressure. The boss at the upper part of the control rod 1 remains stationary under the obstruction of the outer tube 2. The cutting teeth at the lower part of the core barrel 9 are pressed into the soft formation under the action of the drilling fluid pressure to obtain the soft formation core. At the same time, the piston 15 inside the core barrel 9 is connected to the control rod 1. At this time, the piston 15 and the core barrel 9 move relatively, and a negative pressure will be generated below the piston 15, making it easier for the core sample to enter the liner 14, and at the same time reducing the disturbance of the drilling fluid in the hole to the core. The pawl spring 16 in the core barrel 9 prevents the obtained core from falling out of the core barrel 9.

[0023] When the formation drilled is a hard formation, the core barrel 9 of the pressure - injection sampling method cannot be pressed into the formation. At this time, under the action of pressure, the core barrel 9 moves upward and compresses the disc spring 11. The upper part of the core barrel 9 is sleeved outside the valve body 5, thus blocking the passage of drilling fluid into the valve body 5. At the same time, an annular gap is generated between the disc spring seat 8 and the core barrel 9. As the drilling - fluid pressure increases, the drilling - fluid pressure on the upper part of the check valve 3 is greater than the drilling - fluid pressure on the lower part of the weight 4. The check valve 3 pushes the weight 4 to move downward. The weight 4 moves downward and hammers the anvil 7 below and compresses the spring 6, generating a hammering force to drive the core barrel 9 to impact downward and drive the cutting teeth to impact into the formation; during the downward movement of the check valve 3, the check valve 3 is blocked by the valve body 5 and stops moving downward; the weight 4 continues to move downward under the action of inertia, the check valve 3 and the weight 4 are separated from each other, the drilling fluid enters the inside of the valve body 5 from the middle through - hole of the weight 4, and flows out through the first inclined hole on the anvil 7, then passes through the annular gap between the disc spring seat 8 and the core barrel 9, enters the installation chamber for placing the disc spring 11 inside the core barrel 9, and flows into the annular gap between the core barrel 9 and the outer pipe 2 through the second inclined hole on the core barrel 9, and finally returns to the ground orifice through the annular gap between the outer pipe 2 and the hole wall. After the weight 4 hammers the anvil 7, the weight 4 moves upward to the upper end face of the valve body 5 under the action of the spring 6, blocking the circulation channel of the drilling fluid, and the hammering and vibrating mechanism resets to start the next hammering action. After multiple cycles of hammering actions, the core barrel 9 is inserted into a slightly hard formation, the core enters the liner 14, and the claw spring 16 inside the core barrel 9 prevents the obtained core from falling out. During the sampling process, the drilling fluid cannot enter the upper - space of the piston 15 through the check valve, but when the core enters the core barrel 9 and the piston 16 moves upward, the drilling fluid on the upper part of the piston can pass through the check valve and flow out through the inclined holes on the wall of the core barrel 9. When encountering a soft formation again, the force borne by the disc spring 11 decreases. Under the action of the disc spring 11, the core barrel 9 moves downward, opening the drilling - fluid flow channel between the core barrel 9 and the valve body 5, and the drill returns to the pressure - injection sampling mode.

[0024] After sampling, the outer pipe 2 and the drill bit 17 are left in the well. After lifting the rest of the drill structure to the orifice to obtain the core, then start the pump, rotate the outer pipe 2 of the drill to drive the drill bit 17 to continue drilling downward to the formation where the core has been obtained; then repeat the above steps to continue core - drilling.

[0025] As Figure 1 shown, as a preferred embodiment of the present invention, the check valve includes a check - valve seat 13 installed at the connection between the installation chamber and the liner 14. A check - valve ball 12 is arranged on the check - valve seat 13, and the outer diameter of the check - valve ball 12 is greater than the inner diameter of the middle hole of the check - valve seat 13.

[0026] In the embodiment of the present invention, during the sampling process, the drilling fluid cannot enter the upper space of the piston 15 through the check valve ball 12. However, after the core enters the liner 14, during the upward movement of the piston 15, the drilling fluid above the piston 15 can pass through the check valve ball 12 and flow out through the inclined holes on the wall of the core barrel 9.

[0027] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A soft formation drilling device with multi-mode switching, characterized in that It includes an outer pipe and also includes: A control rod, the control rod is connected to the inner wall of the outer pipe through a boss provided on its upper part, and a central hole and side wall through holes are provided on the upper part of the control rod for drilling fluid to enter the inside of the drill tool; A valve body, the valve body is arranged in the outer pipe and forms an annular gap with the outer pipe. A weight and an anvil are installed inside the valve body. The weight is arranged on the upper part of the valve body, and the top of the weight is connected to a live valve above the valve body. The anvil is arranged on the lower part of the valve body, and a spring is connected between the anvil and the weight. The lower end of the anvil extends out of the valve body and is connected to a disc spring seat. First inclined holes are provided at both the upper and lower ends of the side wall of the anvil, and the first inclined holes at both ends of the anvil are communicated with each other through through holes inside it; A core barrel, the core barrel is arranged below the valve body, and the core barrel abuts against the inner wall of the outer pipe through a sealing ring sleeved on its outer wall. An installation chamber is provided at the upper end of the core barrel. A second inclined hole is opened on the side wall of the installation chamber, and the second inclined hole is located below the sealing ring. A disc spring seat is arranged inside the installation chamber. A disc spring is arranged at the bottom of the disc spring seat, and the disc spring is connected to the core barrel. The disc spring seat will be in the upper limit position when only acted by the elastic force of the disc spring. A liner is arranged at the lower part of the core barrel. A piston is installed in the liner, and the piston is connected to the bottom of the control rod. The bottom of the installation chamber is communicated with the liner, and a check valve is arranged at the communication part.

2. The soft formation drilling device with multi-mode switching according to claim 1, characterized in that A claw spring is further arranged at the bottom end of the core barrel.

3. The soft formation drilling device with multi-mode switching according to claim 1, wherein A drill bit is arranged at the bottom of the outer pipe.

4. The soft formation drilling device with multi-mode switching according to claim 1, wherein The check valve includes a check valve seat installed at the communication part between the installation chamber and the liner. A check valve ball is arranged on the check valve seat, and the outer diameter of the check valve ball is larger than the inner diameter of the middle hole in the check valve seat.

Images