Double-circulation scrap collector for well repair and using method of double-circulation scrap collector

Abstract

The invention relates to the technical field of oil and gas field well repair operation tools, in particular to a double-circulation scrap collector for well repair and a using method of the double-circulation scrap collector. Comprising an upper connector, an outer pipe, an inner pipe and a collecting system, the upper connector is connected with the outer pipe and the inner pipe to form an annular cavity, an inlet hole is formed in the top of the inner pipe and communicated with the annular cavity, outlet nozzles are distributed on the pipe wall and connected with the outer pipe in a sealed mode, and a sliding sleeve controls a fluid path through vertical movement in the inner pipe; during reverse circulation, the sliding sleeve moves downwards to open the inlet hole and the outlet nozzle, an annular cavity and inclined hole loop is formed, the lower end of the collecting pipe is closed through a conical cover, centrifugal separation of chippings is accelerated through built-in spiral blades, solid-liquid graded sedimentation is achieved through an outer wall conical ring set through a gradually-shrinking structure, and the chippings enter the collecting pipe to be stored through the outlet hole. The connecting sleeve and the lower connector fix the collecting pipe, and the annular cavity of the collecting pipe is in clearance fit with the conical ring to complete multi-stage filtration. According to the design, a double-circulation mode is achieved through sliding sleeve position switching, and chippings are efficiently collected according to the fluid dynamics principle.

Description

Technical Field

[0001] The present invention relates to the technical field of workover operation tools for oil and gas fields, and particularly to a double-cycle debris collector for workover and its usage method. Background Art

[0002] Debris such as metal debris and rock fragments generated during workover operations are collectively referred to as debris. Debris is likely to precipitate in the wellbore annulus, blocking the workover fluid circulation channel, resulting in problems such as pipe sticking and pump choking, seriously threatening construction safety. Existing debris collection devices need to be manually installed or replaced after stopping the pump, resulting in work interruption, increasing well control risks and time costs. The structure of traditional collection devices is fixed, unable to dynamically adjust the collection capacity according to the amount of debris, and it is difficult to be compatible with different well diameters and workover fluid parameters. Using drilling, grinding, and milling processes in ultra-deep wells poses extremely high risks, with a delay in the feeling of pipe sticking, causing drill pipe fracture. Summary of the Invention

[0003] The main purpose of the present invention is to provide a double-cycle debris collector for workover and its usage method that can automatically switch the circulation path and dynamically collect debris under the condition of not stopping the pump, solving the problems of construction interruption and low debris removal efficiency in the prior art.

[0004] To achieve the above purpose, the technical solution provided by the present invention is as follows: A double-cycle debris collector for workover includes an upper joint. The lower end of the upper joint is fixed with an outer pipe. An inner pipe is fixedly sealed inside the outer pipe below the upper joint. A ring cavity is arranged between the inner pipe and the outer pipe. The upper end of the inner pipe is provided with an inlet hole communicating with the ring cavity. A plurality of outlet nozzles are fixed on the inner pipe. The outlet nozzles communicate with the inside of the inner pipe. The outlet nozzles are fixedly sealed and connected with the outer pipe and communicate with the outside of the outer pipe. A plurality of inclined holes are opened on the outer pipe below the outlet nozzles. The outlet end of the inclined holes inclines downward. The inlet end of the inclined holes communicates with the ring cavity. A sliding sleeve is arranged in the inner pipe. The outer side of the sliding sleeve is in sealing contact with the inner side of the inner pipe. The upper part of the sliding sleeve blocks the inlet hole. The lower part of the sliding sleeve blocks the outlet nozzles. An opening is opened on the sliding sleeve above the outlet nozzles. When the sliding sleeve descends to the lower dead point in the inner pipe, the inlet hole communicates with the ring cavity, and the opening communicates with the outlet nozzles. The lower end of the outer pipe is fixedly sealed and connected with a lower pipe through a connecting sleeve. A collecting pipe is installed inside the lower pipe between the lower joint and the connecting sleeve. An annular cavity is arranged between the outer side of the collecting pipe and the inner side of the lower pipe. The lower end of the collecting pipe is fixedly connected with a conical cover, and the conical cover blocks the lower end of the collecting pipe. A spiral blade is fixed on the inner wall of the collecting pipe. A plurality of conical rings are evenly fixed along the axial direction on the outer side of the collecting pipe. The diameter of the upper end of the conical ring is larger than that of the lower end. A gap is arranged between the outer edge of the upper end of the conical ring and the inner edge of the lower pipe. An outlet hole is opened on the collecting pipe above the conical ring.

[0005] Specifically, a plurality of mounting rods are fixed at both the upper end and the lower end of the collecting pipe. The upper mounting rods tightly abut against the lower end of the connecting sleeve, and the lower mounting rods tightly abut against the upper end of the lower joint.

[0006] Specifically, the lower end of the conical cover is a tip.

[0007] Specifically, the upper end of the sliding sleeve is fixedly connected to the upper joint by shear pins.

[0008] Specifically, a conical surface is provided at the upper end of the sliding sleeve. After the valve ball is seated on the conical surface at the upper end of the sliding sleeve, the valve ball is in sealed contact with the upper end of the sliding sleeve.

[0009] Specifically, the lower joint is connected to the lower pipe through an anti-back-off ring, and the lower pipe is connected to the connecting sleeve through an anti-back-off ring.

[0010] Usage method of the double-circulation debris collector for workover: Install this double-circulation debris collector for workover on the drill and grind string. When the well fluid circulates, the workover fluid passes through this double-circulation debris collector for workover and the drill and grind string and then discharges upward from the annular cavity between the drill and grind string and the wellbore; when debris needs to be collected, a valve ball is dropped into the drill and grind string. After the valve ball is seated on the upper end of the sliding sleeve, the sliding sleeve is blocked. Under the pressure of the workover fluid, the sliding sleeve and the valve ball move downward. When the sliding sleeve and the valve ball move to the lower dead center, the inlet hole communicates with the annular cavity, and the opening hole communicates with the outlet nozzle; the workover fluid above the valve ball is discharged through the inlet hole, the annular cavity, and the inclined hole to the space between the wellbore and this double-circulation debris collector for workover and then moves downward. The workover fluid in the wellbore below the drill and grind string carries debris into the lower joint and then moves upward. The workover fluid carrying debris continues to move upward in the annular cavity between the collecting pipe and the lower pipe under the guiding action of the conical cover. After the workover fluid carrying debris passes through the annular cavity between the collecting pipe and the lower pipe, it enters the sliding sleeve below the valve ball through the connecting sleeve. The workover fluid carrying debris in the sliding sleeve below the valve ball passes through the opening hole and the outlet nozzle and then moves upward between this double-circulation debris collector for workover and the wellbore and is discharged to the ground; when the workover fluid carrying debris moves upward above the collecting pipe, large particles of debris settle to the collecting pipe under the action of gravity; during the upward movement of the workover fluid carrying debris in the annular cavity between the collecting pipe and the lower pipe, when the workover fluid carrying debris flows through the space between the upper end of the conical ring and the lower pipe, the flow rate increases. Therefore, a negative pressure can be generated in the annular cavity part between the collecting pipe and the lower pipe above the conical ring. Under the action of the negative pressure, the workover fluid in the collecting pipe can carry small particles of debris out of the outlet hole into the collecting pipe and move upward with the workover fluid between the lower pipe and the collecting pipe, while the large particles of debris remain in the collecting pipe; during the process of the workover fluid in the collecting pipe carrying small particles of debris out of the outlet hole, the workover fluid in the collecting pipe circulates from the inside to the outside. Under the guiding action of the spiral blade, the workover fluid in the collecting pipe rotates. Under the action of centrifugal force, large particles of debris can be centrifugally settled in the collecting pipe, improving the collection efficiency of large particle debris.

[0011] Compared with the prior art, the beneficial effects of the present invention are: 1. The double - cycle debris collector for workover has a heat - generating double - cycle mode that can be seamlessly switched, significantly improving the operation continuity. Through the linkage design of the sliding sleeve and the valve ball, the automatic switching between normal circulation and reverse circulation is realized. During normal circulation, the sliding sleeve blocks the inlet hole and the outlet nozzle, and the workover fluid directly passes through the drill string to maintain conventional operations. During reverse circulation, the valve ball triggers the sliding sleeve to descend, releasing the annular cavity and the inclined hole passage, forming an efficient debris - carrying path with the outer annulus flowing downward and the inner pipe flowing upward. There is no need to stop the pump or manual intervention, avoiding the well control risks and efficiency losses caused by pump shutdown in traditional devices, especially suitable for complex working conditions in ultra - deep wells.

[0012] 2. The dynamic grading collection system improves the debris processing efficiency and capacity. The collection pipe combines spiral blades, conical rings and negative - pressure adsorption technology to achieve multi - stage sorting and capacity self - adaptation. Large - particle debris directly settles due to gravity at the top of the collection pipe; the spiral blades drive the workover fluid to rotate, strengthening the centrifugal settlement of large particles; the conical - ring diameter - reducing structure accelerates the fluid, and a negative pressure is formed in the upper cavity to actively extract small particles and discharge them into the annular cavity. The grading collection mechanism, that is, large particles are retained and small particles are discharged, avoids the risk of blockage in a single container, extends the continuous operation time, and adapts to the debris volume fluctuations in different well conditions.

[0013] 3. The modular structure design enhances reliability and compatibility. Anti - reverse - buckle ring: The connecting sleeve, the lower pipe and the lower joint are fixed through the anti - reverse - buckle ring to prevent loosening under high - pressure impact. Both ends of the collection pipe are abutted against the connecting sleeve and the lower joint through the installation rod to ensure axial stability and avoid vibration deviation. The lower end of the cone cover is designed to be sharp, guiding the debris to smoothly enter the collection pipe and reducing siltation. The modular architecture is convenient for disassembly and maintenance, and at the same time adapts to different well diameters and workover fluid parameters, reducing the tool customization cost.

[0014] 5. The low - trigger - threshold operation reduces the construction complexity and risks. Based on the valve - ball and shear - pin trigger mechanism, the operation process is simplified. After the valve ball seats on the conical surface of the sliding sleeve, the hydraulic pressure shears the shear pin, driving the sliding sleeve to descend to the preset position, and the action is accurate and controllable; the whole process depends on fluid pressure control, without additional power sources or manual adjustment, reducing the risk of human operation errors. It is suitable for high - risk scenarios such as high - temperature and high - pressure wells and large - inclination wells, significantly improving the construction safety.

[0015] 5. The hydrodynamic optimization design strengthens the debris removal efficiency. The inclined holes of the outer pipe are arranged downward, guiding the workover fluid to impact the debris accumulation area at the bottom of the well, improving the debris entrainment efficiency; the annular cavity provides a stable high - pressure flow, and the conical - ring gap accelerates the fluid to form a local negative pressure. The two paths cooperate to promote the debris to break away from the wellbore; the spiral blades in the collection pipe induce the workover fluid to swirl, prolonging the debris residence time and improving the centrifugal separation effect. The comprehensive fluid control technology breaks through the limitation of the one - way flushing of traditional devices and realizes the closed - loop management of efficient debris removal and dynamic collection. Description of the Drawings

[0016] Figure 1It is a sectional view of this collector before the input valve ball.

[0017] Figure 2 It is a sectional view of this collector after the input valve ball.

[0018] Figure 3 It is Figure 2 An enlarged view of area A in

[0019] Figure 4 It is Figure 2 An enlarged view of area B in

[0020] The names of the parts in the attached drawings are: Specific implementation mode

[0021] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0022] As Figures 1-4 Shown, the double - cycle debris collector for work - over includes an upper sub 1. A lower end of the upper sub 1 is fixedly connected with an outer pipe 2. An inner pipe 3 is fixedly sealed inside the outer pipe 2 below the upper sub 1. A ring cavity 302 is arranged between the inner pipe 3 and the outer pipe 2. An inlet hole 301 communicating with the ring cavity 302 is opened at an upper end of the inner pipe 3. A plurality of nozzles 304 are fixed on the inner pipe 3. The nozzles 304 communicate with the inside of the inner pipe 3. The nozzles 304 are fixedly and sealingly connected with the outer pipe 2 and communicate with the outside of the outer pipe 2. A plurality of inclined holes 303 are opened on the outer pipe 2 below the nozzles 304. An outlet end of the inclined holes 303 inclines downward. An inlet end of the inclined holes 303 communicates with the ring cavity 302. A sliding sleeve 4 is arranged in the inner pipe 3. An upper end of the sliding sleeve 4 is fixedly connected with the upper sub 1 through a shear pin. An outer side of the sliding sleeve 4 is in sealing contact with an inner side of the inner pipe 3. An upper part of the sliding sleeve 4 blocks the inlet hole 301. A lower part of the sliding sleeve 4 blocks the nozzles 304. An opening 401 is opened on the sliding sleeve 4 above the nozzles 304.

[0023] An upper end of the sliding sleeve 4 is provided with a conical surface. After a valve ball 5 is seated on the conical surface at the upper end of the sliding sleeve 4, the valve ball 5 is in sealing contact with the conical surface at the upper end of the sliding sleeve 4.

[0024] After the valve ball 5 is input, when the sliding sleeve 4 descends to the lower dead point in the inner pipe 3, the inlet hole 301 communicates with the ring cavity 302, and the opening 401 communicates with the nozzles 304.

[0025] A lower end of the outer pipe 2 is fixedly and sealingly connected with a lower pipe 6 through a connecting sleeve 14. A lower joint 7 is fixedly and sealingly connected inside a lower end of the lower pipe 6. The lower joint 7 and the lower pipe 6 are connected through an anti - reverse - thread ring. The lower pipe 6 and the connecting sleeve 14 are connected through an anti - reverse - thread ring.

[0026] A collecting pipe 8 is installed inside the lower pipe 6 between the lower joint 7 and the connecting sleeve 14. Specifically, a plurality of mounting rods 12 are fixed to both the upper and lower ends of the collecting pipe 8. The upper mounting rods 12 abut against the lower end of the connecting sleeve 14, and the lower mounting rods 12 abut against the upper end of the lower joint 7.

[0027] An annular cavity is provided between the outer side of the collecting pipe 8 and the inner side of the lower pipe 6. A conical cover 11 is fixedly connected to the lower end of the collecting pipe 8, and the lower end of the conical cover 11 is a tip. The conical cover 11 seals the lower end of the collecting pipe 8. A spiral blade 10 is fixed to the inner wall of the collecting pipe 8. A plurality of conical rings 9 are uniformly fixed along the axial direction of the outer side of the collecting pipe 8. The diameter of the upper end of the conical ring 9 is larger than that of the lower end. A gap is provided between the outer edge of the upper end of the conical ring 9 and the inner edge of the lower pipe 6. An outlet hole 13 is provided on the collecting pipe 8 above the conical ring 9.

[0028] During use, the double - cycle debris collector for workover is installed on the drill - grinding string. When the well fluid circulates, the workover fluid is discharged through the double - cycle debris collector for workover and the drill - grinding string and then discharged upward from the annular cavity between the drill - grinding string and the wellbore 15.

[0029] When debris needs to be collected, a valve ball 5 is put into the drill - grinding string. After the valve ball 5 seats on the upper end of the sliding sleeve 4, the sliding sleeve 4 is blocked. Under the pressure of the workover fluid, the shear pin is cut off, and then the sliding sleeve 4 and the valve ball 5 move downward.

[0030] When the sliding sleeve 4 and the valve ball 5 move to the lower dead center, the inlet hole 301 communicates with the annular cavity 302, and the opening hole 401 communicates with the outlet nozzle 304. The workover fluid above the valve ball 5 is discharged through the inlet hole 301, the annular cavity 302 and the inclined hole 303 to the space between the wellbore 15 and the double - cycle debris collector for workover and then moves downward. The workover fluid in the wellbore 15 below the drill - grinding string carries debris and enters the lower joint 7 and then moves upward.

[0031] The workover fluid carrying debris continues to move upward in the annular cavity between the collecting pipe 8 and the lower pipe 6 under the guiding action of the conical cover 11. After the workover fluid carrying debris passes through the annular cavity between the collecting pipe 8 and the lower pipe 6, it enters the sliding sleeve 4 below the valve ball 5 through the connecting sleeve 14. The workover fluid carrying debris in the sliding sleeve 4 below the valve ball 5 passes through the opening hole 401 and the outlet nozzle 304 and then moves upward between the double - cycle debris collector for workover and the wellbore 15 and is discharged to the ground.

[0032] When the workover fluid carrying debris moves upward above the collecting pipe 8, large - particle debris settles into the collecting pipe 8 under the action of gravity.

[0033] During the upward flow of the workover fluid carrying debris in the annular cavity between the collecting pipe 8 and the lower pipe 6, when the workover fluid carrying debris flows through the space between the upper end of the tapered ring 9 and the lower pipe 6, the flow rate increases. Therefore, a negative pressure can be generated in the annular cavity part between the collecting pipe 8 and the lower pipe 6 above the tapered ring 9. Under the action of the negative pressure, the workover fluid in the collecting pipe 8 can carry small-particle debris and discharge it from the outlet hole 13 into the collecting pipe 8 and then discharge it upward along with the workover fluid between the lower pipe 6 and the collecting pipe 8, while the large-particle debris remains in the collecting pipe 8.

[0034] During the process of the workover fluid in the collecting pipe 8 carrying small-particle debris and discharging it from the outlet hole 13, the workover fluid in the collecting pipe 8 circulates from the inside to the outside. Under the guiding action of the spiral blade 10, the workover fluid in the collecting pipe 8 rotates. Under the action of the centrifugal force, the large-particle debris can be centrifugally settled in the collecting pipe 8, improving the collection efficiency of the large-particle debris.

[0035] 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 principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A double-circulation debris collector for well repair, comprising an upper joint (1), an outer tube (2) being fixed at the lower end of the upper joint (1), characterized in that: An inner tube (3) is fixedly sealed inside an outer tube (2) below the upper joint (1); an annular cavity (302) is provided between the inner tube (3) and the outer tube (2); an inlet hole (301) communicating with the annular cavity (302) is provided at the upper end of the inner tube (3); a plurality of outlet nozzles (304) are fixedly provided on the inner tube (3); the outlet nozzles (304) are communicated with the interior of the inner tube (3); the outlet nozzles (304) are fixedly sealed and connected with the outer tube (2); the outlet nozzles (304) are communicated with the outside of the outer tube (2); and the outlet nozzles (304) are connected to the outer tube (2). 4) is provided with a plurality of inclined holes (303), the outlet ends of the inclined holes (303) are inclined downward, the inlet ends of the inclined holes (303) are communicated with the annular cavity (302), a sliding sleeve (4) is provided in the inner tube (3), the outer side of the sliding sleeve (4) is in sealing contact with the inner side of the inner tube (3), the upper part of the sliding sleeve (4) blocks the inlet hole (301), the lower part of the sliding sleeve (4) blocks the outlet nozzle (304), and an opening (401) is provided on the sliding sleeve (4) above the outlet nozzle (304), When the sliding sleeve (4) moves downward in the inner tube (3) to the lower dead point, the inlet hole (301) is connected to the annular cavity (302), the opening (401) is connected to the outlet nozzle (304), the lower end of the outer tube (2) is fixedly sealed and connected to the lower tube (6) through the connecting sleeve (14), the lower end of the lower tube (6) is fixedly sealed and connected to a lower joint (7), a collecting pipe (8) is installed in the lower tube (6) between the lower joint (7) and the connecting sleeve (14), and a collecting pipe (8) is provided between the outer side of the collecting pipe (8) and the inner side of the lower tube (6). An annular cavity is provided. A cone cover (11) is fixedly connected to the lower end of the collecting pipe (8). The cone cover (11) blocks the lower end of the collecting pipe (8). A spiral blade (10) is fixed on the inner wall of the collecting pipe (8). A plurality of cone rings (9) are evenly distributed and fixed on the outer side of the collecting pipe (8) along the axial direction thereof. The diameter of the upper end of the cone ring (9) is larger than the diameter of the lower end. A gap is provided between the outer edge of the upper end of the cone ring (9) and the inner edge of the lower pipe (6). An outlet hole (13) is provided on the collecting pipe (8) above the cone ring (9).

2. The double-circulation debris collector for well repairing according to claim 1, characterized in that: A plurality of mounting rods (12) are fixed to the upper and lower ends of the collecting pipe (8), the upper mounting rod (12) is tightly against the lower end of the connecting sleeve (14), and the lower mounting rod (12) is tightly against the upper end of the lower joint (7).

3. The double-circulation debris collector for well repairing according to claim 1, characterized in that: The lower end of the cone cover (11) is a pointed end.

4. The double-circulation debris collector for well repairing according to claim 1, characterized in that: The upper end of the sliding sleeve (4) is fixedly connected to the upper joint (1) via shear nails.

5. The double-circulation debris collector for well repairing according to claim 1, characterized in that: The upper end of the sliding sleeve (4) is provided with a conical surface, and the valve ball (5) is seated on the conical surface at the upper end of the sliding sleeve (4), and the valve ball (5) is in sealing contact with the upper end of the sliding sleeve (4).

6. The double-circulation debris collector for well repairing according to claim 1, characterized in that: The lower joint (7) is connected to the lower tube (6) via an anti-backlash ring, and the lower tube (6) is connected to the connecting sleeve (14) via an anti-backlash ring.

7. The method for using the double-circulation debris collector for well repairing according to claim 1, characterized in that: The double-circulation debris collector for well repair is installed on the drilling and grinding pipe string. When the well fluid circulates, the well repair fluid is discharged from the annular cavity between the drilling and grinding pipe string and the wellbore (15) after passing through the double-circulation debris collector for well repair. When debris needs to be collected, a valve ball (5) is inserted into the drilling and grinding pipe string. After the valve ball (5) is seated on the upper end of the sliding sleeve (4), the sliding sleeve (4) is blocked. Under the pressure of the well repair fluid, the sliding sleeve (4) and the valve ball (5) move downward. When the sliding sleeve (4) and the valve ball (5) move to the lower dead point, the inlet hole (301) is connected with the annular cavity (302), and the opening (401) is connected with the outlet (304); the valve ball (5) The well repair fluid at the top is discharged through the inlet hole (301), the annular cavity (302) and the inclined hole (303) to the space between the wellbore (15) and the double-circulation debris collector for well repair and then moves downward. The well repair fluid in the wellbore (15) below the drilling and grinding pipe string carries the debris into the lower joint (7) and then moves upward. The well repair fluid carrying the debris continues to move upward in the annular cavity between the collecting pipe (8) and the lower pipe (6) under the guidance of the cone cover (11). The well repair fluid carrying the debris passes through the annular cavity between the collecting pipe (8) and the lower pipe (6) and then passes through the connecting sleeve (14) and enters the sliding sleeve (4) below the valve ball (5). The workover fluid carrying debris passes through the opening (401) and the outlet (304) and then ascends between the double-circulation debris collector for well workover and the wellbore (15) and is discharged to the ground. When the workover fluid carrying debris ascends above the collecting pipe (8), large particles of debris settle into the collecting pipe (8) under the action of gravity. When the workover fluid carrying debris ascends in the annular cavity between the collecting pipe (8) and the lower pipe (6), the flow velocity of the workover fluid carrying debris increases when it flows through the space between the upper end of the cone ring (9) and the lower pipe (6), thereby generating negative pressure in the annular cavity between the collecting pipe (8) and the lower pipe (6) above the cone ring (9). Under the action of negative pressure, the well repairing fluid in the collection pipe (8) can carry small particles of debris and be discharged from the outlet hole (13) to the collection pipe (8) and discharged upward along with the well repairing fluid between the lower pipe (6) and the collection pipe (8), while large particles of debris remain in the collection pipe (8); in the process of the well repairing fluid in the collection pipe (8) carrying small particles of debris being discharged from the outlet hole (13), the well repairing fluid in the collection pipe (8) circulates from the inside to the outside, and under the guidance of the spiral blade (10), the well repairing fluid in the collection pipe (8) rotates, and under the action of centrifugal force, large particles of debris can be centrifugally settled in the collection pipe (8), thereby improving the collection efficiency of large particles of debris.

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