A device and method for quantitative injection and optimization of oilfield drilling fluid

Abstract

The invention discloses a quantitative injection and optimization device and method for oilfield drilling fluid, which belongs to the technical field of drilling fluid injection, and comprises a water collecting hood and a casing column fixedly connected at the center of the top of the water collecting hood, a circular opening is opened at the center of the bottom end of the water collecting hood, the casing column is arranged through the circular opening, a mud pipe is fixedly connected to the surface of the casing column, a plurality of impurity discharge openings distributed in a circumference are opened on the surrounding side walls of the water collecting hood, the inner bottom end of the water collecting hood is rotatably connected with a rotating tube at the circular opening, and the top of the rotating tube is rotatably connected with a fixed tube; S1, quantitative drilling fluid; S2, circulating and filtering drilling fluid; S3, automatic impurity discharge. The invention is provided with a water collecting hood, a double-axis motor, an impeller, a negative pressure box and a suspension plate. When the drilling fluid enters the water collecting hood, the suspension plate floats up, and the spur plate floats up with it. When the spur plate drives the gear to rotate and then drives the valve stem to rotate, after the circulation valve is opened, it means that the amount of drilling fluid in the water collecting hood is just right, and the quantitative function of the drilling fluid is realized.

Description

Technical Field

[0001] The invention relates to the technical field of oilfield drilling fluid injection, and in particular to an oilfield drilling fluid quantitative injection and optimization device and method. Background Art

[0002] Drilling fluid is an important component in the drilling process. Its main functions in the drilling process include carrying cuttings, balancing formation pressure, cooling and lubricating the drill bit, protecting the well wall, transmitting hydraulic power, and providing formation data.

[0003] The existing drilling fluid is to use a pump body to inject water (most of the existing drilling fluid is water) into the wellbore through the casing string, and use the water pressure to make the drilling fluid overflow along the wellbore. During the overflow of the drilling fluid, it will impact the mud cake on the well wall, thereby flushing out the impurities such as cuttings in the wellbore. The existing drilling fluid injection device does not have a filtering structure, so that the overflowed drilling fluid will flow along the ground and cannot be recycled. At the same time, the flushed out impurities such as cuttings will be dispersed on the ground under the flushing effect of the drilling fluid, and it is not easy to recover;

[0004] In addition, the existing drilling fluid injection device does not have a quantitative effect and cannot control the amount of drilling fluid according to the depth of the wellbore, which easily causes a waste of water resources. For arid areas with scarce water resources, drilling operations will greatly increase the burden on water resources in the area. Therefore, an oilfield drilling fluid quantitative injection and optimization device and method are proposed to solve the above problems. Summary of the invention

[0005] The purpose of the present invention is to solve the problems in the prior art and to propose an oilfield drilling fluid quantitative injection and optimization device and method.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A quantitative injection and optimization device for oilfield drilling fluid comprises a water collecting hood and a casing column fixedly connected to the center of the top end of the water collecting hood, a circular opening is opened at the center of the bottom end of the water collecting hood, the casing column is arranged through the circular opening, a mud pipe is fixedly connected to the surface of the casing column, a plurality of circumferentially distributed impurity discharge openings are opened on the surrounding side walls of the water collecting hood, a rotating tube is rotatably connected to the inner bottom end of the water collecting hood at the circular opening, a fixed tube is rotatably connected to the top end of the rotating tube, a plurality of circumferentially distributed openings are opened on the surrounding side walls of the fixed tube, a filter cover is fixedly connected to the surface of the rotating tube, one end of the filter cover is rotatably connected to the inner wall of the water collecting hood, a suspension plate is slidably connected to the surface of the rotating tube, a motor box is fixedly connected to the inner top end of the water collecting hood, a dual-shaft motor is installed inside the motor box, an output shaft at one end of the dual-shaft motor is fixedly connected to an impeller, a negative pressure box is arranged on the outer side of the impeller, a pipeline assembly is arranged on the side wall of the negative pressure box, and a linkage assembly is arranged on the output shaft at the other end of the dual-shaft motor.

[0008] Preferably, a side wall of the water collecting cover is fixedly connected with a drain pipe, an outer side wall of the water collecting cover is rotatably connected with an impurity recovery box at the impurity discharge port, and a magnet block is provided at the bottom end of the impurity recovery box.

[0009] Preferably, a magnetic ring having the same magnetic pole as the magnet block is fixedly connected to the top of the suspension plate, and a spur plate is fixedly connected to the top of the suspension plate.

[0010] Preferably, a drain port is provided at one end of the negative pressure box, a water extraction port is provided at the center of the negative pressure box, and the pipeline assembly includes a connecting pipe fixedly connected to the drain port and a water extraction pipe fixedly connected to the water extraction port.

[0011] Preferably, a water pumping valve is provided on the water pumping pipe, a circulation pipe is fixedly connected to the surface of the water pumping pipe, one end of the circulation pipe is fixedly connected to the side wall of the water collecting cover, and a circulation valve is provided on the circulation pipe.

[0012] Preferably, the valve stem of the circulation valve is rotatably connected to the side wall of the water collecting cover, one end of the valve stem penetrates the side wall of the water collecting cover and is fixedly connected to a driven gear meshing with a spur gear plate, and a plurality of circumferentially distributed prompt plates are fixedly connected to the surface of the valve stem.

[0013] Preferably, the linkage assembly includes an active synchronous wheel fixedly connected to one end of the output shaft at the other end of the dual-axis motor, a driven synchronous wheel fixedly connected to the surface of the rotating tube, and a synchronous belt connected between the driven synchronous wheel and the active synchronous wheel.

[0014] A method for quantitative injection and optimization of oilfield drilling fluid comprises the following steps:

[0015] S1. Quantitative drilling fluid: close the circulation valve, open the pumping valve, start the dual-shaft motor, and the dual-shaft motor drives the impeller to rotate to realize the function of extracting drilling fluid. The external drilling fluid can be pumped into the casing string through the pumping pipe and the connecting pipe. The drilling fluid in the casing string is injected into the inside of the wellbore. Then, under the action of pressure, the drilling fluid overflows upward along the wellbore, and finally flows into the inside of the water collecting cover through the opening on the side wall of the fixed pipe, so that the suspension plate floats up, and then drives the spur plate to move up. When the spur plate meshes with the driven gear and drives the driven gear to rotate, the valve stem drives the prompt plate to rotate, and the opening function of the circulation valve is realized at the same time. At this time, it means that the amount of drilling fluid in the water collecting cover is just right;

[0016] S2. Circulating and filtering drilling fluid: The drilling fluid in the water collecting cover is pumped into the casing column under the action of the dual-axis motor and the impeller, and finally discharged into the water collecting cover through the opening on the side wall of the fixed pipe to realize circulation. In the process of the drilling fluid being discharged into the water collecting cover, the filter cover can filter the impurities such as cuttings in the drilling fluid. The dual-axis motor cooperates with the linkage assembly to realize the rotation function of the rotating tube, and then realize the rotation function of the filter cover. The centrifugal force of the filter cover can be used to throw the impurities such as cuttings on the surface of the filter cover into the impurity recovery box for recovery;

[0017] S3. Automatic impurity discharge: After the drilling fluid has completed circulation inside the wellbore, open the drain valve on the drain pipe to discharge and recycle the drilling fluid in the water collecting cover. When the drilling fluid is discharged, the suspension plate moves down and resets. During this process, the spur plate drives the driven gear to rotate in the opposite direction, and then drives the valve stem to rotate, realizing the closing function of the circulation valve. At the same time, under the action of the repulsive force between the magnetic ring and the magnet block at the bottom of the impurity recovery box, the impurity recovery box is opened, so that the rock cuttings and other impurities inside are automatically discharged for easy recovery.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. The present invention is provided with a water collecting cover, a dual-axis motor, an impeller, a negative pressure box and a suspension plate. When the drilling fluid enters the water collecting cover, the suspension plate floats up, and the spur plate floats up along with it. When the spur plate drives the gear to rotate and then drives the valve stem to rotate, after the circulation valve is opened, it means that the amount of drilling fluid in the water collecting cover is just right, thereby realizing the quantitative function of the drilling fluid.

[0020] 2. The present invention is provided with a dual-axis motor, a pipeline assembly, a linkage assembly and a filter cover. When the drilling fluid is discharged into the inner side of the water collecting cover, the filter cover can filter out impurities inside the drilling fluid. At the same time, the dual-axis motor cooperates with the linkage assembly to realize the rotation function of the rotating tube, and then realizes the rotation function of the filter cover. The centrifugal force of the filter cover can be used to throw impurities such as cuttings on the surface of the filter cover into the impurity recovery box for recovery. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram of the three-dimensional structure of an oilfield drilling fluid quantitative injection and optimization device and method proposed by the present invention;

[0022] Figure 2 The internal structure of the device and method for quantitative injection and optimization of oilfield drilling fluid proposed by the present invention is shown in FIG. Figure 1 ;

[0023] Figure 3 The invention provides a device and method for quantitative injection and optimization of oilfield drilling fluid.

[0024] The internal structure of the law Figure 2 ;

[0025] Figure 4 for Figure 3 The enlarged structural diagram at A in the middle;

[0026] Figure 5 This is a schematic diagram of the connection structure of a rotating pipe, a fixed pipe and a linkage assembly in an oilfield drilling fluid quantitative injection and optimization device and method proposed by the present invention;

[0027] Figure 6 This is a schematic diagram of the structure of a suspension plate in an oilfield drilling fluid quantitative injection and optimization device and method proposed by the present invention;

[0028] Figure 7 The present invention provides a method flow chart of a device and method for quantitative injection and optimization of oilfield drilling fluid.

[0029] In the figure: 1, water collecting cover; 101, impurity discharge port; 2, impurity recovery box; 3, casing column; 4, mud pipe; 5, water suction pipe; 6, circulation pipe; 7, circulation valve; 8, prompt board; 9, fixed pipe; 901, opening; 10, driven synchronous wheel; 11, synchronous belt; 12, rotating pipe; 13, active synchronous wheel; 14, dual-axis motor; 15, negative pressure box; 16, impeller; 17, motor box; 18, magnetic ring; 19, suspension plate; 20, spur plate; 21, driven gear; 22, filter cover. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0031] Reference Figure 1-7, an oilfield drilling fluid quantitative injection and optimization device, comprising a water collecting cover 1 and a casing column 3 fixedly connected to the center of the top of the water collecting cover 1, a circular opening is opened at the center of the bottom of the water collecting cover 1, and the circular opening is set to facilitate the drilling fluid overflowing from the wellbore to flow into the rotating pipe 12 and the inner side of the fixed pipe 9; the casing column 3 is set through the circular opening, and a mud pipe 4 is fixedly connected to the surface of the casing column 3, and the mud pipe 4 is set to inject mud into the casing column 3;

[0032] The surrounding side walls of the water collecting cover 1 are provided with a plurality of impurity discharge ports 101 distributed in a circular pattern. The inner bottom end of the water collecting cover 1 is rotatably connected to a rotating tube 12 at the circular port. The top of the rotating tube 12 is rotatably connected to a fixed tube 9. The surrounding side walls of the fixed tube 9 are provided with a plurality of openings 901 distributed in a circular pattern. The arrangement of the openings 901 facilitates the discharge of drilling fluid into the water collecting cover 1. A filter cover 22 is fixedly connected to the surface of the rotating tube 12. One end of the filter cover 22 is rotatably connected to the inner wall of the water collecting cover 1. The filter cover 22 can filter out impurities such as rock cuttings inside the drilling fluid. A suspension plate 19 is slidably connected to the surface of the rotating tube 12. The suspension plate 19 can move upward as the drilling fluid level rises, providing a prerequisite for the quantitative measurement of the drilling fluid.

[0033] The top of the inner side of the water collecting cover 1 is fixedly connected with a motor box 17, a double-shaft motor 14 is installed inside the motor box 17, an output shaft at one end of the double-shaft motor 14 is fixedly connected with an impeller 16, and a negative pressure box 15 is arranged outside the impeller 16;

[0034] It should be noted that: the dual-axis motor 14 drives the impeller 16 to rotate, and with the cooperation of the negative pressure box 15, negative pressure can be generated at the inner center of the negative pressure box 15, so that the external drilling fluid can be pumped into the inner side of the water pumping pipe 5, realizing the drilling fluid extraction function;

[0035] A pipeline assembly is provided on the side wall of the negative pressure box 15, a drain port is provided at one end of the negative pressure box 15, a water pumping port is provided at the center of the negative pressure box 15, the pipeline assembly includes a connecting pipe fixedly connected to the drain port and a water pumping pipe 5 fixedly connected to the water pumping port, a water pumping valve is provided on the water pumping pipe 5, a circulation pipe 6 is fixedly connected to the surface of the water pumping pipe 5, one end of the circulation pipe 6 is fixedly connected to the side wall of the water collecting cover 1, and a circulation valve 7 is provided on the circulation pipe 6;

[0036] It should be noted that the connecting pipe cooperates with the circulation pipe 6 to realize the circulation function of the drilling fluid in the water collecting box, the casing string 3 and the inside of the wellbore;

[0037] The pumping pipe 5 cooperates with the dual-shaft motor 14, the impeller 16 and the negative pressure box 15 to pump the external drilling fluid into the casing string 3;

[0038] The output shaft at the other end of the dual-axis motor 14 is provided with a linkage assembly, which includes a driving synchronous wheel 13 fixedly connected to one end of the output shaft at the other end of the dual-axis motor 14, a driven synchronous wheel 10 fixedly connected to the surface of the rotating tube 12, and a synchronous belt 11 connected between the driven synchronous wheel 10 and the driving synchronous wheel 13;

[0039] It should be noted that: the dual-axis motor 14 drives the active synchronous wheel 13 to rotate, and then drives the driven synchronous wheel 10 to rotate through the synchronous belt 11, the driven synchronous wheel 10 drives the rotating tube 12 to rotate, and the rotating tube 12 drives the filter cover 22 to rotate, and the centrifugal force of the filter cover 22 can be used to throw the impurities such as cuttings on the surface of the filter cover 22 into the impurity recovery box 2 for recovery;

[0040] The side wall of the water collecting cover 1 is fixedly connected with a drain pipe, the outer side wall of the water collecting cover 1 is rotatably connected with an impurity recovery box 2 at the impurity discharge port 101, a magnet block is arranged at the bottom end of the impurity recovery box 2, the top end of the suspension plate 19 is fixedly connected with a magnetic ring 18 having the same magnetic pole as the magnet block, and the top end of the suspension plate 19 is fixedly connected with a straight tooth plate 20.

[0041] It should be noted that the drain pipe can realize the function of draining the drilling fluid inside the water collecting cover 1, which is convenient for the recovery of the drilling fluid; under the action of the repulsive force between the magnetic ring 18 and the magnet block at the bottom end of the impurity recovery box 2, the impurity recovery box 2 is opened, so that the impurities such as rock cuttings inside are automatically discharged for easy recovery.

[0042] The valve stem of the circulation valve 7 is rotatably connected to the side wall of the water collecting cover 1, one end of the valve stem penetrates the side wall of the water collecting cover 1 and is fixedly connected to a driven gear 21 meshing with a spur plate 20, and a plurality of prompt plates 8 distributed in a circumference are fixedly connected to the surface of the valve stem;

[0043] It should be noted that: when the suspension plate 19 floats up, it drives the spur plate 20 to move up. When the spur plate 20 meshes with the driven gear 21 and drives the driven gear 21 to rotate, the valve stem drives the prompt plate 8 to rotate, and the opening function of the circulation valve 7 is realized at the same time. At this time, it means that the amount of drilling fluid in the water collecting cover 1 is just right.

[0044] A method for quantitative injection and optimization of oilfield drilling fluid comprises the following steps:

[0045] The first step is to quantitatively feed drilling fluid: close the circulation valve 7, open the pumping valve, and start the dual-axis motor 14. The dual-axis motor 14 drives the impeller 16 to rotate to realize the function of extracting drilling fluid. The external drilling fluid can be pumped into the casing column 3 through the pumping pipe 5 and the connecting pipe. The drilling fluid in the casing column 3 is injected into the inside of the wellbore. Then, under the action of pressure, the drilling fluid overflows upward along the wellbore, and finally flows into the inside of the water collecting cover 1 through the opening 901 on the side wall of the fixed pipe 9, so that the suspension plate 19 floats up, and then drives the spur plate 20 to move up. When the spur plate 20 meshes with the driven gear 21 and drives the driven gear 21 to rotate, the valve stem drives the prompt plate 8 to rotate, and at the same time realizes the opening function of the circulation valve 7. At this time, it means that the amount of drilling fluid in the water collecting cover 1 is just right;

[0046] Step 2: Circulate and filter the drilling fluid: The drilling fluid in the water collecting cover 1 is pumped into the casing column 3 under the action of the dual-axis motor 14 and the impeller 16, and finally discharged into the water collecting cover 1 through the opening 901 on the side wall of the fixed pipe 9 to realize circulation. In the process of the drilling fluid being discharged into the water collecting cover 1, under the action of the filter cover 22, the filtering function of impurities such as cuttings in the drilling fluid can be realized, and the rotation function of the rotating tube 12 is realized by the dual-axis motor 14 and the linkage assembly, and then the rotation function of the filter cover 22 is realized. By using the centrifugal force of the filter cover 22, the impurities such as cuttings on the surface of the filter cover 22 can be thrown into the impurity recovery box 2 for recovery;

[0047] The third step is automatic impurity discharge: after the drilling fluid has completed circulation inside the wellbore, open the drain valve on the drain pipe to discharge and recycle the drilling fluid in the water collecting cover 1. After the drilling fluid is discharged, the suspension plate 19 moves down and resets. During this process, the spur plate 20 drives the driven gear 21 to rotate in the opposite direction, thereby driving the valve stem to rotate, thereby realizing the closing function of the circulation valve 7. At the same time, under the action of the repulsive force between the magnetic ring 18 and the magnet block at the bottom of the impurity recovery box 2, the impurity recovery box 2 is opened, so that the impurities such as rock cuttings inside are automatically discharged for easy recovery.

[0048] The dual-axis motor 14 is a prior art, and its model is JB5274-91. It can realize the function of driving the impeller 16 and the active synchronous wheel 13 to rotate, and will not be described in detail here.

[0049] When the present invention is in use, the circulation valve 7 is closed, the pumping valve is opened, and the dual-axis motor 14 is turned on. The dual-axis motor 14 drives the impeller 16 to rotate and cooperate with the negative pressure box 15 to realize the function of extracting drilling fluid. The external drilling fluid can be pumped into the casing column 3 through the pumping pipe 5 and the connecting pipe. The drilling fluid in the casing column 3 is injected into the inside of the wellbore. Then, under the action of pressure, the drilling fluid overflows upward along the wellbore and finally flows into the inside of the water collecting cover 1 through the opening 901 on the side wall of the fixed pipe 9, so that the suspension plate 19 floats up, and then drives the spur plate 20 to move up. When the spur plate 20 meshes with the driven gear 21 and drives the driven gear 21 to rotate, the valve stem drives the prompt plate 8 to rotate, and the opening function of the circulation valve 7 is realized at the same time. At this time, it means that the amount of drilling fluid in the water collecting cover 1 is just right. After the staff observes that the prompt plate 8 rotates, the pumping valve is closed;

[0050] Then, the drilling fluid in the water collecting cover 1 is pumped into the casing column 3 under the action of the dual-axis motor 14 and the impeller 16, and finally discharged into the water collecting cover 1 through the opening 901 on the side wall of the fixed pipe 9 to realize circulation. In the process of the drilling fluid being discharged into the water collecting cover 1, under the action of the filter cover 22, the filtering function of impurities such as cuttings in the drilling fluid can be realized, and the rotation function of the rotating tube 12 is realized by the dual-axis motor 14 and the linkage assembly, and then the rotation function of the filter cover 22 is realized. By utilizing the centrifugal force of the filter cover 22, the impurities such as cuttings on the surface of the filter cover 22 can be thrown into the impurity recovery box 2 for recovery;

[0051] After the drilling fluid has completed circulation inside the wellbore, the drain valve on the drain pipe is opened to discharge and recycle the drilling fluid in the water collecting cover 1. When the drilling fluid is discharged, the suspension plate 19 moves down and resets. During this process, the spur plate 20 drives the driven gear 21 to rotate in the opposite direction, thereby driving the valve stem to rotate, thereby realizing the closing function of the circulation valve 7. At the same time, under the action of the repulsive force between the magnetic ring 18 and the magnet block at the bottom of the impurity recovery box 2, the impurity recovery box 2 is rotated open, so that the impurities such as rock cuttings inside are automatically discharged for easy recovery.

[0052] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An oilfield drilling fluid quantitative injection and optimization device, comprising a water collecting cover (1) and a casing string (3) fixedly connected to the center of the top of the water collecting cover (1), characterized in that: The water collecting cover (1) has a circular opening at the center of the bottom end, the casing column (3) is arranged to pass through the circular opening, a mud pipe (4) is fixedly connected to the surface of the casing column (3), a plurality of circumferentially distributed debris discharge openings (101) are opened on the surrounding side walls of the water collecting cover (1), a rotating pipe (12) is rotatably connected to the inner bottom end of the water collecting cover (1) at the circular opening, a fixed pipe (9) is rotatably connected to the top end of the rotating pipe (12), a plurality of circumferentially distributed openings (901) are opened on the surrounding side walls of the fixed pipe (9), and a filter cover (101) is fixedly connected to the surface of the rotating pipe (12). 22), one end of the filter cover (22) is rotatably connected to the inner wall of the water collecting cover (1), the surface of the rotating tube (12) is slidably connected to a suspension plate (19), the inner top end of the water collecting cover (1) is fixedly connected to a motor box (17), a dual-axis motor (14) is installed inside the motor box (17), an output shaft at one end of the dual-axis motor (14) is fixedly connected to an impeller (16), a negative pressure box (15) is arranged on the outer side of the impeller (16), a pipeline assembly is arranged on the side wall of the negative pressure box (15), and a linkage assembly is arranged on the output shaft at the other end of the dual-axis motor (14); The side wall of the water collecting cover (1) is fixedly connected to a liquid discharge pipe, and the outer side wall of the water collecting cover (1) is rotatably connected to an impurity recovery box (2) at the impurity discharge port (101), and a magnet block is provided at the bottom end of the impurity recovery box (2); The top end of the suspension plate (19) is fixedly connected to a magnetic ring (18) having the same magnetic pole as the magnet block, and the top end of the suspension plate (19) is fixedly connected to a spur plate (20); A drainage port is provided at one end of the negative pressure box (15), a water extraction port is provided at the center of the negative pressure box (15), and the pipeline assembly comprises a connecting pipe fixedly connected to the drainage port and a water extraction pipe (5) fixedly connected to the water extraction port; The water pumping pipe (5) is provided with a water pumping valve, a circulation pipe (6) is fixedly connected to the surface of the water pumping pipe (5), one end of the circulation pipe (6) is fixedly connected to the side wall of the water collecting cover (1), and a circulation valve (7) is provided on the circulation pipe (6); The valve stem of the circulation valve (7) is rotatably connected to the side wall of the water collecting cover (1), one end of the valve stem penetrates the side wall of the water collecting cover (1) and is fixedly connected to a driven gear (21) meshing with a spur gear plate (20), and a plurality of circumferentially distributed prompt plates (8) are fixedly connected to the surface of the valve stem.

2. The device for quantitative injection and optimization of oilfield drilling fluid according to claim 1, characterized in that: The linkage assembly comprises a driving synchronous wheel (13) fixedly connected to one end of an output shaft at the other end of a dual-axis motor (14), a driven synchronous wheel (10) fixedly connected to the surface of a rotating tube (12), and a synchronous belt (11) connected between the driven synchronous wheel (10) and the driving synchronous wheel (13).

3. A method for using the oilfield drilling fluid quantitative injection and optimization device as claimed in claim 1, comprising the following steps: S1. Quantitative drilling fluid: close the circulation valve (7), open the pumping valve, start the double-shaft motor (14), and the double-shaft motor (14) drives the impeller (16) to rotate to realize the function of extracting drilling fluid. The external drilling fluid can be pumped into the casing column (3) through the pumping pipe (5) and the connecting pipe. The drilling fluid in the casing column (3) is injected into the inner side of the wellbore. Then, under the action of pressure, the drilling fluid overflows upward along the wellbore and finally flows into the inner side of the water collecting cover (1) through the opening on the side wall of the fixed pipe (9), so that the suspension plate (19) floats up, and then drives the spur plate (20) to move upward. When the spur plate (20) meshes with the driven gear (21) and drives the driven gear (21) to rotate, the valve stem drives the prompt plate (8) to rotate, and at the same time realizes the opening function of the circulation valve (7). At this time, it means that the amount of drilling fluid in the water collecting cover (1) is just right; S2, circulating and filtering the drilling fluid: the drilling fluid in the water collecting cover (1) is pumped into the casing column (3) under the action of the dual-axis motor (14) and the impeller (16), and finally discharged into the water collecting cover (1) through the opening on the side wall of the fixed pipe (9) to realize circulation. In the process of the drilling fluid being discharged into the water collecting cover (1), the filter cover (22) can filter the rock cuttings impurities in the drilling fluid, and the dual-axis motor (14) and the linkage assembly can realize the rotation function of the rotating tube (12), thereby realizing the rotation function of the filter cover (22). The centrifugal force of the filter cover (22) can be used to throw the rock cuttings impurities on the surface of the filter cover (22) into the impurity recovery box (2); S3. Automatic impurity discharge: After the drilling fluid has been circulated inside the wellbore, the drain valve on the drain pipe is opened to discharge the drilling fluid in the water collecting cover (1) for recovery. After the drilling fluid has been discharged, the suspension plate (19) moves downward to reset. During this process, the spur plate (20) drives the driven gear (21) to rotate in the opposite direction, thereby driving the valve stem to rotate, thereby realizing the closing function of the circulation valve (7). At the same time, under the action of the repulsive force between the magnetic ring (18) and the magnet block at the bottom of the impurity recovery box (2), the impurity recovery box (2) is opened, so that the rock cuttings and impurities inside are automatically discharged, which is convenient for recovery.

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