A multi-functional drill pipe device and its method for clearing holes and sampling

Abstract

The present invention discloses a multifunctional drill pipe device and a method for hole cleaning and sampling thereof, which includes a drill pipe assembly, a soil sampler assembly and a water stop ball; the drill pipe assembly is in a hollow cylindrical shape, with an open bottom bit, a first through hole for water injection formed at the center of the top joint, and first movable limiting tendons, second movable limiting tendons and circumferential fixing tendons are respectively arranged on its inner wall from top to bottom, and spring bodies are built in both the first movable limiting tendon and the second movable limiting tendon; the soil sampler assembly is placed inside the drill pipe assembly, and the soil sampler assembly is in a hollow cylindrical shape, with an open bottom and a second through hole for water passing formed at the top; the water stop ball is placed into the drill pipe assembly through the first through hole and blocks the second through hole. By using the drill pipe device of the present invention, during the process of offshore geological exploration drilling and sampling, the two operations of hole cleaning and sampling can be completed by one-time lowering, which greatly improves the work efficiency, saves the offshore geological exploration operation time and promotes the construction of sea wind.

Description

Technical Field

[0001] The present invention relates to the technical field of offshore wind power geological exploration, and in particular to a multifunctional drill pipe device and a method for clearing holes and sampling thereof. Background Art

[0002] Accelerating the construction of offshore wind power is one of the important ways to achieve the national carbon neutrality strategic goal. However, due to the action of complex random environmental loads such as wind, waves, and currents, the safety window period for operations such as offshore exploration is limited, which affects the construction speed of offshore wind power. Therefore, how to shorten the offshore exploration operation time is of extremely important significance for ensuring personnel safety, accelerating the construction of offshore wind power, and indirectly promoting the realization of the carbon neutrality goal.

[0003] At present, in the process of geological exploration drilling and sampling using existing drilling technologies, generally, a thin (thick) wall soil sampler is first used to take soil samples, and then the drill pipe is used to clean the hole opening, and then the thin (thick) wall soil sampler is used to take soil samples from the lower layer, and so on, repeating the offshore geological exploration drilling and sampling work. In this process, both the process of taking soil samples by the soil sampler and the process of clearing the hole by the drill pipe involve the operation of retracting and lowering the drill pipe at the operation wellhead, with a long operation time and low operation efficiency. Summary of the Invention

[0004] The first object of the present invention is to provide a multifunctional drill pipe device to achieve the purpose of simultaneously clearing the hole and sampling by lowering the drill pipe once.

[0005] The second object of the present invention is to provide a method for clearing holes and sampling of the multifunctional drill pipe device.

[0006] The first object of the present invention can be achieved by adopting the following technical solutions:

[0007] A multifunctional drill pipe device, comprising a drill pipe assembly, a soil sampler assembly and a water stop ball; the drill pipe assembly is in a hollow cylindrical shape, with an open bottom bit, and a first through hole for water injection is formed at the center of the top joint. First movable limiting tendons, second movable limiting tendons and circumferential fixing tendons are respectively arranged on the inner wall from top to bottom. Springs are built in both the first movable limiting tendon and the second movable limiting tendon, and the strength of the built-in spring of the first movable limiting tendon is greater than that of the built-in spring of the second movable limiting tendon; the soil sampler assembly is built inside the drill pipe assembly and can move up and down inside the drill pipe assembly. The soil sampler assembly is in a hollow cylindrical shape, with an open bottom and a second through hole for water flow formed at the top. In the initial state, the soil sampler assembly is restricted to the upper part of the drill pipe assembly by the first movable limiting tendon. Water is injected into the drill pipe assembly through the first through hole, and the water flow flows into the soil sampler assembly through the second through hole and then out of the bit of the drill pipe assembly to perform hole cleaning operation; the water stop ball is placed into the drill pipe assembly through the first through hole and blocks the second through hole. Under the action of water pressure, the soil sampler assembly breaks through the restriction of the first movable limiting tendon and moves downward along the drill pipe assembly to between the second movable limiting tendon and the circumferential fixing tendon, and the soil sampler assembly is restricted to the lower part of the drill pipe assembly by the second movable limiting tendon and the circumferential fixing tendon to perform sampling operation.

[0008] Further, the drill pipe assembly includes an upper drill pipe, a bit and a joint. The upper drill pipe is a hollow straight rod. The joint is connected to the top of the upper drill pipe and is used to connect a common drill pipe. The bit is connected to the bottom of the upper drill pipe. The upper part of the inner wall of the upper drill pipe is provided with a first movable limiting tendon with a built-in spring, and the lower part of the inner wall is provided with a second movable limiting tendon with a built-in spring. A first through hole for water injection is formed at the center of the top of the joint. A circumferential fixing tendon for restricting the soil sampler assembly from coming out is arranged on the inner wall of the bit.

[0009] Further, the soil sampler assembly includes a thin-wall soil sampler, an upper limiting sleeve and a lower limiting sleeve. The upper limiting sleeve and the lower limiting sleeve are connected by threads. The outer diameter of the top of the thin-wall soil sampler matches the inner diameter of the lower limiting sleeve. The thin-wall soil sampler is sleeved inside the lower limiting sleeve. The thin-wall soil sampler is restricted to the upper part of the drill pipe assembly by the cooperation of the first movable limiting tendon and the lower limiting sleeve. The thin-wall soil sampler is restricted to the lower part of the drill pipe assembly by the cooperation of the second movable limiting tendon, the circumferential fixing tendon and the upper limiting sleeve, and its head extends out of the bit. A second through hole for water injection is formed at the center of the top of the upper limiting sleeve. The second through hole is in a stepped shape, with its upper inner diameter larger than the lower inner diameter and smaller than the inner diameter of the first through hole, and the upper inner diameter of the second through hole matches the diameter of the water stop ball. The water stop ball is stuck into the upper part of the second through hole and blocks the lower part of the second through hole.

[0010] Furthermore, the thin-walled soil sampler is in the shape of a conical cylinder with a constant inner diameter and a gradually decreasing outer diameter from top to bottom.

[0011] Furthermore, the top surface of the second through hole is concave and matches the water-stop ball, so that the water-stop ball can accurately fall into the second through hole.

[0012] Furthermore, a threaded section for connecting with the lower limit sleeve is formed at the lower part of the inner wall of the upper limit sleeve, the upper part is a non-threaded section, and the inner diameter of the upper part is consistent with the inner diameter of the thin-walled soil sampler.

[0013] The second object of the present invention can be achieved by adopting the following technical solutions:

[0014] The hole cleaning and sampling method of the above-mentioned multi-functional drill pipe device includes:

[0015] Set the drill pipe device to the initial state, that is, place the soil sampler assembly inside the drill pipe assembly and limit it to the upper part of the drill pipe assembly through the first movable limiting tendon, and the water-stop ball is not installed inside the drill pipe assembly;

[0016] Connect the joint of the drill pipe assembly with a common drill pipe, place the drill pipe assembly with the built-in soil sampler assembly and the common drill pipe into the outer riser pre-installed at the deck wellhead, and lower them along the outer riser to the working mud surface. The space between the outer riser and the drill pipe assembly forms a mud water flow channel;

[0017] Connect the drill rig to the drill pipe assembly through the common drill pipe at the deck working surface. Use the water pump supporting the drill rig to pass water into the drill pipe assembly through the common drill pipe. The water flows through the first through hole at the top of the drill pipe assembly and the second through hole at the top of the soil sampler assembly into the inside of the soil sampler assembly and reaches the working mud surface. Drive the drill pipe assembly to rotate by the drill rig and drive its drill bit to perform hole cleaning operation at the working mud surface. The washed mud water flows upward out of the outer riser through the mud water flow channel;

[0018] Drive the drill pipe assembly to descend to a predetermined height by the drill rig. When the flowing mud water is uniform and the mud particles meet the requirements, stop the drill rig to complete the hole cleaning operation at the hole opening;

[0019] Lift the common drill pipe and the drill pipe assembly to make the drill bit away from the mud surface. When the lifting height is greater than the height of the thin-walled soil sampler of the soil sampler assembly, turn off the water pump, release the water-stop ball from the through hole at the top end of the common drill pipe at the deck working surface. The water-stop ball falls along the through hole of the common drill pipe and the first through hole at the top of the drill pipe assembly under the action of gravity and gets stuck in the upper part of the second through hole, blocking the lower part of the second through hole through the water-stop ball;

[0020] Turn on the water pump and pressurize it. Under the action of water pressure, the soil sampler assembly breaks through the restriction of the first movable limiting tendon and moves downward. When it descends to the lower part of the drill pipe assembly, the soil sampler assembly is fixed to the lower part of the drill pipe assembly through the second movable limiting tendon and the circumferential fixing tendon, and its head extends out of the drill bit.

[0021] Turn off the water pump and lower the drilling rig while pressing down the drill pipe assembly, thereby piercing the soil sampler assembly into the soil. After pressing down to the predetermined height, lift the drill pipe assembly to the deck working surface to complete the sampling operation of the soil sampler assembly.

[0022] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0023] 1. During the offshore geological exploration drilling and sampling process, the present invention can complete two operations of hole cleaning and sampling by lowering once, greatly improving work efficiency, saving offshore geological exploration operation time, and promoting seabreeze construction.

[0024] 2. The drill pipe device of the present invention has a simple structure, is easy to operate and maintain. Compared with other complex soil samplers, it is especially suitable for engineering applications in cooperation with existing technical equipment, has a wide applicability and good economy. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic structural diagram of the drill pipe device of the present invention.

[0026] Figure 2 It is a schematic structural diagram of the drill pipe device of the present invention during sampling.

[0027] Figure 3 It is a schematic structural diagram of the soil sampler assembly of the present invention.

[0028] Figure 4 It is a schematic structural diagram of the thin-wall soil sampler of the present invention.

[0029] Figure 5 It is a schematic structural diagram of the upper limit sleeve of the present invention.

[0030] Figure 6 It is a schematic structural diagram of the lower limit sleeve of the present invention.

[0031] Figure 7 It is a schematic structural diagram of the drill bit of the present invention.

[0032] Figure 8 It is a schematic structural diagram of the joint of the present invention.

[0033] Figure 9 It is a schematic structural diagram of the upper drill pipe of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0034] The present invention will be further described below in conjunction with specific embodiments, but the usage mode of the present invention is not limited thereto.

[0035] As Figures 1 to 9 shown, this embodiment provides a multi-functional drill pipe device, which includes a drill pipe assembly 1, a soil sampler assembly 2, and a water stop ball 3.

[0036] The drill pipe assembly 1 is in the shape of a hollow cylinder, with an open bottom drill bit 102. A first through hole 1031 for water injection is formed at the center of the top joint 103. First movable limiting tendons 1011, second movable limiting tendons 1012, and circumferential fixing tendons 1022 are respectively arranged on its inner wall from top to bottom. The first movable limiting tendon 1011 is internally provided with a strong spring body, and the second movable limiting tendon 1012 is internally provided with a weak spring body. The soil sampler assembly 2 is placed inside the drill pipe assembly 1 and can move up and down inside the drill pipe assembly 1. The soil sampler assembly 2 is in the shape of a hollow cylinder, with an open bottom and a second through hole 2021 for water passage formed at the top. In the initial state, the soil sampler assembly 2 is restricted to the upper part of the drill pipe assembly 1 by the first movable limiting tendon 1011. Water is injected into the drill pipe assembly 1 through the first through hole 1031, and the water flow flows into the soil sampler assembly 2 through the second through hole 2021 and then out of the drill bit 102 of the drill pipe assembly 1 for hole cleaning operation. The water stop ball 3 is placed into the drill pipe assembly 1 through the first through hole 1031 and blocks the second through hole 2021. The soil sampler assembly 2 breaks through the restriction of the first movable limiting tendon 1011 under the action of water pressure and moves down along the drill pipe assembly 1 to between the second movable limiting tendon 1012 and the circumferential fixing tendon 1022, and the soil sampler assembly 2 is restricted to the lower part of the drill pipe assembly 1 by the second movable limiting tendon 1012 and the circumferential fixing tendon 1022 for sampling operation.

[0037] The drill pipe assembly 1 includes an upper drill pipe 101, a drill bit 102, and a joint 103. The upper drill pipe 101 is a hollow straight rod. The bottom of the joint 103 is connected to the top of the upper drill pipe 101 by internal threads, and its top is connected to a common drill pipe by internal threads. A first through hole 1031 for water injection is formed at the center of its top. The first through hole 1031 is communicated with the through hole of the common drill pipe and has the same size. The top of the drill bit 102 is connected to the bottom of the upper drill pipe 101 by external threads. A circle of small drill bits 1021 is arranged at intervals along the circumference at its bottom. A circumferential fixing tendon 1022 for restricting the soil sampler assembly 2 from coming out is arranged on its inner wall. The upper part of the inner wall of the upper drill pipe 101 is provided with a first movable limiting tendon 1011 with a strong spring body inside, and the lower part of its inner wall is provided with a second movable limiting tendon 1012 with a weak spring body inside.

[0038] The soil sampler assembly 2 includes a thin-wall soil sampler 201, an upper limit sleeve 202 and a lower limit sleeve 203. The upper limit sleeve 202 and the lower limit sleeve 203 are connected by threads, and the overall length after the connection of the upper limit sleeve 202 and the lower limit sleeve 203 is slightly smaller than the distance between the second movable limit tendon 1012 and the circumferential fixing tendon 1022. The thin-wall soil sampler 201 is made of stainless steel, and the outer diameter of its top matches the inner diameter of the lower limit sleeve 203. The thin-wall soil sampler 201 is sleeved inside the lower limit sleeve 203. The thin-wall soil sampler 201 is restricted to the upper part of the drill pipe assembly 1 by the cooperation of the first movable limit tendon 1011 and the lower limit sleeve 203. The thin-wall soil sampler 201 is restricted to the lower part of the drill pipe assembly 1 by the cooperation of the second movable limit tendon 1012, the circumferential fixing tendon 1022 and the upper limit sleeve 202, and its head extends out of the drill bit 102. A second through hole 2021 for water injection is formed at the center of the top of the upper limit sleeve 202. The second through hole 2021 is stepped, the inner diameter of its upper part is larger than that of the lower part and slightly smaller than the inner diameter of the first through hole 1031, and the inner diameter of the upper part of the second through hole 2021 matches the diameter of the water stop ball 3. The water stop ball 3 is stuck into the upper part of the second through hole 2021 to block the lower part of the second through hole 2021.

[0039] Further, the thin-wall soil sampler 201 has a conical tube structure with a constant inner diameter and a gradually decreasing outer diameter from top to bottom.

[0040] Further, the top surface of the second through hole 2021 is concave and matches the water stop ball 3, so that the water stop ball 3 can accurately fall into the second through hole 2021.

[0041] Further, a threaded section for connecting with the lower limit sleeve 203 is formed at the lower part of the inner wall of the upper limit sleeve 202, the upper part is a non-threaded section, and the inner diameter of the upper part is consistent with the inner diameter of the thin-wall soil sampler 201.

[0042] This embodiment also provides an installation method based on the above multi-functional drill pipe device. The method includes the following steps:

[0043] 1) Directly sleeve the thin-wall soil sampler 201 inside the lower limit sleeve 203. The lower limit sleeve 203 can restrict the downward displacement of the thin-wall soil sampler 201. Connect the upper limit sleeve 202 and the lower limit sleeve 203 by threads. The upper limit sleeve 202 can restrict the upward displacement of the thin-wall soil sampler 201 to complete the assembly of the soil sampler assembly 2. At this time, the thin-wall soil sampler 201 is in a completely fixed state;

[0044] 2) Connect the bottom of the upper drill pipe 101 and the drill bit 102 by threads. At this time, both the upper and lower ends of the upper drill pipe 101 are in an open state;

[0045] 3) Place the assembled soil sampler assembly 2 from step 1) into the top of the upper drill pipe 101. Since the first movable limiting tendon 1011 with a strong spring body is built into the upper part of the inner wall of the upper drill pipe 101, at this time, the thin-walled soil sampler 201 is restricted to the upper part of the upper drill pipe 101 through the cooperation of the first movable limiting tendon 1011 and the lower limiting sleeve 203, and the top of the upper limiting sleeve 202 is close to being flush with the top of the upper drill pipe 101;

[0046] 4) Connect the top of the upper drill pipe 101 to the joint 103 by threads. At this time, the installation of the main components of the drill pipe device on the deck working plane is completed (all the above thread connections are tightened in the same direction); the water stop ball 3 is placed inside the drill pipe assembly 1 through the first through hole 1031 according to requirements during use.

[0047] This embodiment also provides a hole cleaning and sampling method based on the above multifunctional drill pipe device, and the method includes the following steps:

[0048] 1) Set the drill pipe device to the initial state, that is, the whole soil sampler assembly is built inside the drill pipe assembly, the soil sampler assembly is restricted to the upper part of the drill pipe assembly through the first movable limiting tendon, and the water stop ball is not installed inside the drill pipe assembly;

[0049] 2) Connect a common drill pipe to the top of the joint by threads, place the drill pipe assembly and the common drill pipe as a whole into the outer riser pre-installed at the deck wellhead, and lower it along the outer riser to the working mud surface. The space between the inner wall of the outer riser and the outer wall of the drill pipe assembly forms a mud water flow channel;

[0050] 3) Connect the drill rig to the drill pipe assembly through the common drill pipe on the deck working surface, and use the water pump supporting the drill rig to pass water into the drill pipe assembly through the common drill pipe. The water flows into the inside of the soil sampler assembly through the first through hole at the top of the drill pipe assembly and the second through hole at the top of the soil sampler assembly and reaches the working mud surface. The drill rig drives the drill pipe assembly to rotate and drives its drill bit to perform hole cleaning operation at the hole mouth on the working mud surface. The washed mud water flows upward out of the outer riser through the mud water flow channel;

[0051] 4) Drive the drill pipe assembly to descend to a predetermined height by the drill rig. When the mud water flowing out of the mud water flow channel flows evenly and there are no large particles in the mud, it means that the hole mouth cleaning is completed, and stop the drill rig;

[0052] 5) Lift the common drill pipe and the drill pipe assembly to make the drill bit away from the mud surface. When the lifting height is greater than the height of the thin-walled soil sampler, turn off the water pump, release the water stop ball from the through hole at the top of the common drill pipe on the deck working surface. The water stop ball falls along the through hole of the common drill pipe and the first through hole at the top of the drill pipe assembly under the action of gravity and gets stuck in the upper part of the second through hole, and blocks the lower part of the second through hole through the water stop ball;

[0053] 6) Turn on the water pump and pressurize it. Since the second through-hole of the upper limit sleeve is blocked by the water-stop ball, the soil sampler assembly breaks through the restriction of the first movable limit tendon under the action of water pressure and moves downward. When it descends to the lower part of the drill pipe assembly, the soil sampler assembly is fixed to the lower part of the drill pipe assembly through the second movable limit tendon and the circumferential fixing tendon. At this time, the head of the thin-wall soil sampler extends out of the drill bit;

[0054] 7) Turn off the water pump and lower the drilling rig at the same time to press down the drill pipe assembly, so as to pierce the thin-wall soil sampler into the soil. During this process, the water flow and waste soil inside the thin-wall soil sampler can flow upward from the second through-hole;

[0055] During the pressing-down process, check in real time whether the thin-wall soil sampler has been lowered in place. If the lowering is successful, the on-site operator will feel a sense of resistance during the process of lowering the drilling rig; if the sense of resistance has not been felt after the lowering height exceeds the lifting height in step 5), it means that the lowering of the thin-wall soil sampler has failed, and then return to step 5); if it has not been lowered in place, raise the position of the drill pipe and increase the water pressure until the thin-wall soil sampler is lowered in place;

[0056] After pressing down to the predetermined height, lift the drill pipe assembly to the deck working surface to complete the sampling operation of the soil sampler assembly;

[0057] 8) Release the connections between the drill bit and the upper rod of the drill pipe, the upper limit sleeve and the lower limit sleeve, and the thin-wall soil sampler and the lower limit sleeve in sequence, then take out the thin-wall soil sampler and level and cut the soil sample, and seal and wax the two ends of the thin-wall soil sampler to complete the soil sample packaging.

[0058] The above-mentioned embodiments are only the preferred embodiments of the present invention, and do not limit the scope of implementation of the present invention. Therefore, all changes made according to the shape and principle of the present invention should be covered within the protection scope of the present invention.

Claims

1. A multi-functional drill pipe device, characterized in that: It includes a drill pipe assembly, a soil sampler assembly and a water stop ball; the drill pipe assembly is in the shape of a hollow cylinder, with an open bottom bit, and a first through hole for water injection is formed at the center of the top joint. First movable limiting tendons, second movable limiting tendons and circumferential fixing tendons are respectively arranged on its inner wall from top to bottom. Spring bodies are built in both the first movable limiting tendon and the second movable limiting tendon, and the strength of the built-in spring body of the first movable limiting tendon is greater than that of the built-in spring body of the second movable limiting tendon; the soil sampler assembly is built inside the drill pipe assembly and can move up and down inside the drill pipe assembly. The soil sampler assembly is in the shape of a hollow cylinder, with an open bottom and a second through hole for water passing formed at the top. In the initial state, the soil sampler assembly is restricted to the upper part of the drill pipe assembly by the first movable limiting tendon. Water is injected into the drill pipe assembly through the first through hole, and the water flow flows into the soil sampler assembly through the second through hole and then out of the bit of the drill pipe assembly for hole cleaning operation. The soil sampler assembly includes a thin-wall soil sampler, an upper limiting sleeve and a lower limiting sleeve. The upper limiting sleeve and the lower limiting sleeve are connected by threads. The outer diameter of the top of the thin-wall soil sampler matches the inner diameter of the lower limiting sleeve. The thin-wall soil sampler is sleeved inside the lower limiting sleeve. The thin-wall soil sampler is restricted to the upper part of the drill pipe assembly by the cooperation of the first movable limiting tendon and the lower limiting sleeve. The thin-wall soil sampler is restricted to the lower part of the drill pipe assembly by the cooperation of the second movable limiting tendon, the circumferential fixing tendon and the upper limiting sleeve, and its head extends out of the bit. A second through hole for water injection is formed at the center of the top of the upper limiting sleeve. The second through hole is in a stepped shape, with its upper inner diameter larger than the lower inner diameter and smaller than the inner diameter of the first through hole, and the upper inner diameter of the second through hole matches the diameter of the water stop ball. The water stop ball is stuck into the upper part of the second through hole and blocks the lower part of the second through hole; the water stop ball is placed into the drill pipe assembly through the first through hole and blocks the second through hole. Under the action of water pressure, the soil sampler assembly breaks through the restriction of the first movable limiting tendon and moves down along the drill pipe assembly to between the second movable limiting tendon and the circumferential fixing tendon. The soil sampler assembly is restricted to the lower part of the drill pipe assembly by the second movable limiting tendon and the circumferential fixing tendon for sampling operation.

2. The multi-functional drill pipe device according to claim 1, characterized in that: The drill pipe assembly includes an upper drill pipe, a bit and a joint. The upper drill pipe is a hollow straight rod. The joint is connected to the top of the upper drill pipe for connecting a common drill pipe. The bit is connected to the bottom of the upper drill pipe. A first movable limiting tendon with a built-in spring body is arranged at the upper part of the inner wall of the upper drill pipe, and a second movable limiting tendon with a built-in spring body is arranged at the lower part of its inner wall. A first through hole for water injection is formed at the center of the top of the joint. A circumferential fixing tendon for restricting the soil sampler assembly from coming out is arranged on the inner wall of the bit.

3. The multi-functional drill pipe device according to claim 1, wherein: The thin-wall soil sampler is in the shape of a conical cylinder with a constant inner diameter and a gradually decreasing outer diameter from top to bottom.

4. The multi-functional drill pipe device according to claim 1, characterized in that: The top surface of the second through hole is concave and matches the water stop ball, so that the water stop ball can accurately fall into the second through hole.

5. The multi-functional drill pipe device according to claim 1, characterized in that: The lower part of the inner wall of the upper limit sleeve is formed with a threaded section for connecting with the lower limit sleeve, the upper part is a non-threaded section, and the inner diameter of the upper part is consistent with the inner diameter of the thin-wall soil sampler.

6. The hole cleaning and sampling method of the multi-functional drill pipe device according to claim 1, characterized in that Including: Set the drill pipe device to the initial state, that is, place the soil sampler assembly inside the drill pipe assembly and restrict it at the upper part of the drill pipe assembly through the first movable limiting tendon, and no water-stop ball is installed inside the drill pipe assembly; Connect the joint of the drill pipe assembly with a common drill pipe, place the drill pipe assembly with the built-in soil sampler assembly and the common drill pipe into the outer riser pre-installed at the deck wellhead, and lower them along the outer riser to the working mud surface. The space between the outer riser and the drill pipe assembly forms a mud water flow channel; On the deck working surface, connect the drill rig to the drill pipe assembly through the common drill pipe, use the water pump supporting the drill rig to pass water into the drill pipe assembly through the common drill pipe. The water flow flows into the inside of the soil sampler assembly through the first through hole at the top of the drill pipe assembly and the second through hole at the top of the soil sampler assembly and reaches the working mud surface. Drive the drill pipe assembly to rotate by the drill rig and drive its drill bit to perform hole cleaning operation at the hole opening on the working mud surface. The mud water washed out flows upward through the mud water flow channel and out of the outer riser; Drive the drill pipe assembly to descend to a predetermined height by the drill rig. When the flowing mud water is uniform and the mud particles meet the requirements, stop the drill rig to complete the hole cleaning operation at the hole opening; Lift the common drill pipe and the drill pipe assembly to make the drill bit away from the mud surface. When the lifted height is greater than the height of the thin-wall soil sampler of the soil sampler assembly, turn off the water pump, and release the water-stop ball from the through hole at the top of the common drill pipe on the deck working surface. The water-stop ball falls along the through hole of the common drill pipe and the first through hole at the top of the drill pipe assembly under the action of gravity and gets stuck in the upper part of the second through hole, blocking the lower part of the second through hole through the water-stop ball; Turn on the water pump and pressurize. The soil sampler assembly breaks through the restriction of the first movable limiting tendon under the action of water pressure and moves downward. When it descends to the lower part of the drill pipe assembly, fix the soil sampler assembly at the lower part of the drill pipe assembly through the second movable limiting tendon and the circumferential fixing tendon, and its head extends out of the drill bit; Turn off the water pump and at the same time lower the drill rig to press down the drill pipe assembly, and then pierce the soil sampler assembly into the soil. After pressing down to the predetermined height, lift the drill pipe assembly to the deck working surface to complete the sampling operation of the soil sampler assembly.

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