CN212671703U

CN212671703U - Anti-backflow downhole tool

Info

Publication number: CN212671703U
Application number: CN202021524593.9U
Authority: CN
Inventors: 不公告发明人
Original assignee: Daqing Xindefeng Petroleum Technology Co ltd
Current assignee: Daqing Xindefeng Petroleum Technology Co ltd
Priority date: 2020-07-29
Filing date: 2020-07-29
Publication date: 2021-03-09
Anticipated expiration: 2030-07-29

Abstract

The utility model provides an anti-return's downhole tool. Relates to the field of oil field downhole tools. The inner hole of the upper pipe is provided with a valve core, the upper part of the valve core is in clearance fit connection with the central hole of the upper pipe through a sealing ring, the periphery of the pipe wall of the valve core is provided with evenly distributed side holes, the lower part of the valve core is provided with a step ring, the upper part of the step ring of the valve core is connected with the internal thread end face of the middle pipe connected with the upper pipe, the circular ring plane of the step ring of the valve core is provided with vertical holes which are communicated up and down, and a spring is arranged between the step ring and the step hole of the middle. The valve core is supported at the lower end of the upper pipe through the spring, when downward air pressure is reduced, the valve core rises under the action of the spring, when the sealing ring enters the central hole of the upper pipe, the upper space and the lower space of the sealing ring are cut off, before reverse air flow reaches, the sealing ring closes the air flow channel, and the phenomenon that the valve core is blocked cannot occur.

Description

Anti-backflow downhole tool

The technical field is as follows:

the utility model belongs to the technical field of the oil field instrument technique in the pit and specifically relates to an anti-return's instrument in the pit.

Background art:

the air drilling is a means for drilling the stratum by using air as a flushing fluid, has the advantages of high drilling speed, prolonged service life of a drilling tool, reduced stratum damage and the like, is more and more widely applied to the current mining and drilling process, is an underbalanced drilling technology, and determines that the method is greatly influenced by the pressure change of stratum fluid, when the pressure of injected air is changed, air backflow is possibly caused, and the drill string is polluted and blocked due to the fact that backflow air carries broken rock debris, so that a device capable of preventing gas backflow is needed;

the improvement measures disclosed at present generally lead to the structure of valve shaft, case and spring constitution check valve in device casing and circulation barrel, play the effect that prevents the gas backward flow, valve shaft and case closed position directly expose in the direction of air backward flow, lack corresponding isolation or collection subassembly, when shutoff air intlet, the clearance that spills is very easily blockked up by detritus and silt that carry in the air that flows back, arouses the component card to die for the device is malfunctioning, and then leads to whole pipeline to block up.

The utility model has the following contents:

in order to solve the problem, the utility model provides an anti-return downhole tool.

The technical scheme of the utility model is that: an anti-backflow downhole tool comprises an upper pipe, wherein an upper joint is arranged on the upper part of the upper pipe, the lower part of the upper pipe is in threaded sealing connection with a middle pipe, the lower part of the middle pipe is in threaded sealing connection with a lower pipe, a lower joint is arranged below the lower pipe, and the upper pipe, the middle pipe and the lower pipe are all provided with central holes;

the inner hole of the upper pipe is provided with a valve core, the upper part of the valve core is in clearance fit connection with the central hole of the upper pipe through a sealing ring, the center of the upper part of the valve core is provided with a counter bore, the upper part of the sealing ring is provided with evenly distributed side holes on the pipe wall of the counter bore of the valve core, the lower part of the valve core is provided with a step ring, the upper part of the step ring of the valve core is connected with the internal thread end face of the middle pipe through the upper pipe, the circular ring plane of the step ring of the valve core is provided with vertical holes which are communicated up and down, and a spring is arranged.

The middle pipe and the lower pipe are in threaded sealing connection, a section of annular groove is formed in the lower portion of an internal thread hole of the lower pipe, and a filter screen and a flow guide cover are clamped between the table surface of a threaded bottom hole in the upper portion of the annular groove and the end surface of an external thread inner pipe of the middle pipe;

the air guide sleeve comprises a side ring and a bowl-shaped groove, the side ring is clamped at the lower part of the filter screen, the bowl opening of the bowl-shaped groove is arranged towards the lower opening, the bowl-shaped groove and the side ring are connected through a plurality of supporting rib plates, a gap between the supporting rib plates forms an overflowing hole, the overflowing hole is communicated with the inner hole of the side ring, and the bottom of the bowl-shaped groove is not in contact with the bottom of the ring groove of the lower pipe.

The utility model discloses following beneficial effect has: the lower extreme of pipe in upper portion is pushed up the case through the spring, it diminishes as decurrent atmospheric pressure, the case rises under the effect of spring, when the sealing washer gets into the centre bore of upper portion pipe, the space is promptly cut off about the sealing washer, before reverse air current reachs, the sealing washer has closed airflow channel, reverse air current and impurity entering case upper portion can not have, the phenomenon that the case was blocked by the card stagnation can not take place yet, the filter screen is arranged in blockking the detritus and the silt that carry in the return air, detritus and silt that carry in most air current can be returned the pit by bowl shape groove refracting surface, further play the effect of stopping.

Description of the drawings:

fig. 1 is a schematic structural diagram of the present invention;

fig. 2 is a top view of the dome of the present invention;

fig. 3 is a schematic diagram of the operation of the present invention.

In the figure, 1-an upper pipe, 2-a middle pipe, 3-a lower pipe, 4-an upper joint, 5-a lower joint, 6-a valve core, 7-a side hole, 8-a vertical hole, 9-a spring, 10-a counter bore, 11-a filter screen, 12-a flow guide cover, 13-a bowl-shaped groove, 14-a side ring, 15-an overflowing hole, 16-an inner ring hole, 17-a ring groove, 18-a support rib plate, 19-a step ring and 20-a step hole.

The specific implementation mode is as follows:

the present invention will be further explained with reference to the accompanying drawings:

referring to fig. 1 and fig. 2-3, the backflow-preventing downhole tool comprises an upper pipe 1, wherein an upper joint 4 is arranged at the upper part of the upper pipe 1, the lower part of the upper pipe 1 is in threaded sealing connection with a middle pipe 2, the lower part of the middle pipe 2 is in threaded sealing connection with a lower pipe 3, a lower joint 5 is arranged below the lower pipe 3, and the upper pipe 1, the middle pipe 2 and the lower pipe 3 are provided with central holes;

the inner hole of the upper pipe 1 is provided with a valve core 6, the upper part of the valve core 6 is in clearance fit connection with the central hole of the upper pipe 1 through a sealing ring, the valve core 6 is provided with a counter bore 10 at the upper center of the upper part, the upper part of the sealing ring is provided with evenly distributed side holes 7 at the periphery of the pipe wall of the counter bore 10 of the valve core 6, the lower part of the valve core 6 is provided with a step ring 19, the upper part of the step ring 19 of the valve core 6 is jointed with the internal thread end face of the upper pipe 1 connected with the middle pipe 2, the circular ring plane of the step ring 19 of the valve core 6 is provided with vertical holes 8 which are communicated up and down, a spring 9 is arranged between the step ring 19 and the step hole 20 of the middle pipe 2, the step ring 19 of the valve core 6 is pressed against the lower end of the upper pipe 1 through the spring 9, at the moment, the side holes 7 are sealed in the central hole of the upper pipe 1 by, the side hole 7 descends to expose under the upper portion pipe centre bore, and the air current just can pass through counter bore 10, side hole 7, found the hole 8 and get into the lower part, when the air current takes place reverse flow, diminishes when decurrent atmospheric pressure, case 6 rises under the effect of spring 9, when the sealing washer gets into the centre bore of upper portion pipe 1, the space is cut off promptly about the sealing washer, before the reverse air current arrived, the sealing washer has closed the air current passageway, can not have reverse air current and impurity to get into case 6 upper portion, can not take place the phenomenon emergence that case 6 was blocked yet.

The middle pipe 2 and the lower pipe 3 are in threaded sealing connection, a section of annular groove 17 is formed in the lower portion of an internal threaded hole of the lower pipe 3, a filter screen 11 and a flow guide cover 12 are clamped between the table top of a threaded bottom hole in the upper portion of the annular groove 17 and the end face of an external threaded inner pipe of the middle pipe 2, the filter screen 11 is used for blocking detritus and silt carried in backflow air, when normal airflow flows downwards, the detritus and the silt carried in the blocked backflow air can be flushed out of the filter screen 11 by the downward airflow, and the filter screen 11 cannot be blocked;

the air guide sleeve 12 comprises a side ring 14 and a bowl-shaped groove 13, the side ring 14 is clamped at the lower part of the filter screen 11, a bowl opening of the bowl-shaped groove 13 is arranged towards a downward opening, the bowl-shaped groove 13 and the side ring 14 are connected through a plurality of supporting rib plates 18, a gap between the supporting rib plates 18 forms an overflowing hole 15, the overflowing hole 15 is communicated with an inner ring hole 16 of the side ring 14, the bottom of the bowl-shaped groove 13 is not in contact with the bottom of a ring groove 17 of the lower pipe 3, airflow enters the ring groove 17 through the inner ring hole 16 and the overflowing hole 15 and then flows out, the bowl-shaped groove 13 with the downward opening can form a reflecting surface for reverse airflow, and most of debris and silt carried in the airflow can be refracted by the bowl-shaped groove 13 to return to the underground, so that the blocking effect is.

Claims

1. A downhole tool for backflow prevention, comprising an upper pipe (1), characterized in that: an upper joint (4) is arranged at the upper part of the upper pipe (1), the lower part of the upper pipe (1) is in threaded sealing connection with the middle pipe (2), the lower part of the middle pipe (2) is in threaded sealing connection with the lower pipe (3), a lower joint (5) is arranged below the lower pipe (3), and the upper pipe (1), the middle pipe (2) and the lower pipe (3) are all provided with central holes;

the inner hole of the upper pipe (1) is provided with a valve core (6), the upper part of the valve core (6) is connected with the central hole of the upper pipe (1) through a sealing ring in a clearance fit manner, the valve core (6) is provided with a counter bore (10) in the upper center, the upper part of the sealing ring is provided with edge holes (7) which are uniformly distributed on the periphery of the pipe wall of the counter bore (10) of the valve core (6), the lower part of the valve core (6) is provided with a step ring (19), the upper part of the step ring (19) of the valve core (6) is connected with the upper pipe (1) and is jointed with the internal thread end face of the middle pipe (2), the circular ring plane of the step ring (19) of the valve core (6) is provided with vertical holes (8) which are communicated up and down, and a spring (9) is arranged between the step.

2. A downhole tool for backflow prevention according to claim 1, wherein: the middle pipe (2) and the lower pipe (3) are in threaded sealing connection, a section of annular groove (17) is formed in the lower portion of an internal threaded hole of the lower pipe (3), and a filter screen (11) and a flow guide cover (12) are clamped between the table surface of a threaded bottom hole in the upper portion of the annular groove (17) and the end surface of an external threaded inner pipe of the middle pipe (2);

the air guide sleeve (12) comprises a side ring (14) and a bowl-shaped groove (13), the side ring (14) is clamped at the lower part of the filter screen (11), a bowl opening of the bowl-shaped groove (13) is arranged towards the lower opening, the bowl-shaped groove (13) and the side ring (14) are connected through a plurality of support rib plates (18), a gap between the support rib plates (18) forms an overflowing hole (15), the overflowing hole (15) is communicated with an annular inner hole (16) of the side ring (14), and the bottom of the bowl-shaped groove (13) is not contacted with the bottom of an annular groove (17) of the lower pipe (3).