Flushing mechanism for bit balling drum

Abstract

The utility model relates to the technical field of drilling tools, in particular to a flushing mechanism for a bit balling drum. The flushing mechanism for the drill bit balling drum comprises a flushing head which is arranged between an oil and gas well drill rod and a drill bit and is provided with a central cavity channel; a flushing channel is formed in the wall of the central cavity channel; the fixing piece is fixed in the central cavity channel; the fixing piece cuts off the central cavity channel, and a first through main hole is formed in the fixing piece; a slot is formed between the fixing piece and the inner wall of the central cavity channel, and a first side hole is formed in the slot of the fixing piece; the movable part can be arranged in the central cavity channel in a telescopic mode in the axial direction through an elastic assembly; and the movable piece is provided with a plug part, and a second through main hole is further formed in the movable piece. Drilling displacement is changed through ground operation, so that pressure drop of a drill bit is changed, spring force is overcome, a flushing channel is opened and closed, drilling fluid from a cleaning bypass directly flushes a chip groove of the drill bit, the structure is simple, the cleaning effect is good, the service life is long, and reliability is high.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of drilling tools, especially a flushing mechanism for a bit balling up. BACKGROUND

[0002] In the process of drilling for oil and gas or natural gas, the bit will be wrapped in mud (referred to as balling up) when drilling or tripping. When the bit has balling up, the teeth of the bit cannot leak out, resulting in the teeth being unable to contact the well wall, so that the bit cannot be driven (the bit cannot continue to advance), and the bit has to be forced to be tripped, seriously affecting the speed of oil and gas exploitation.

[0003] There are many reasons for the generation of balling up, which can be roughly divided into geological factors, mud performance factors, engineering technology and operation factors, and bit selection factors. When balling up occurs, the degree of bit tooth "eating into" the formation is reduced due to the influence of balling up, resulting in that the drilling force cannot be normally exerted, the drilling speed is slowed down, and in severe cases, the bit cannot be drilled, no footage is obtained, and the bit has to be forced to be tripped, increasing the cost and labor intensity. The phenomenon of "pulling piston" occurs when tripping; the mud cannot be filled when tripping, suction is generated, the downhole liquid column pressure is reduced, the oil, gas and water in the formation enter the wellbore, causing downhole collapse, and serious consequences such as well blowout and fire; at the same time, the mud is polluted; when tripping, the downhole pressure fluctuation is easily caused, the well wall is unstable, the block is generated, and the lost circulation is caused. After the bit balling up occurs, the annular obstruction may also be caused, thereby causing the sticking accident. In addition, when the piston and valve rubber of the mud pump, the rubber of the hose and screw rod, and the sundries in the mud block the bit water hole, the bit balling up may also be caused, and the mud pump drilling tool may also be damaged due to pressure.

[0004] At present, whether at home or abroad, when dealing with bit balling up, the bit balling up is repeatedly removed at different depths and different directions of the wellbore by idling and large displacement circulation. However, this method has very poor effect, and it is unknown when the balling up is removed and whether the balling up can be removed, so the whole process of dealing with the balling up is very long.

[0005] Based on the experience of the inventor, an auxiliary device for flushing the bit balling up has been designed before. When the auxiliary device is used in actual drilling, the customer feedback is that the effect of removing the balling up is good, but the reliability may not be ideal, for example, the service life, and the flushing head needs to be replaced every time the bit is drilled for a period of time.

[0006] Therefore, based on the target of customer requirements "simple structure, high reliability, and excellent effect of removing balling up", the inventor adopts a new design idea. SUMMARY

[0007] The utility model discloses a flushing mechanism for drill bit mud ball, which overcomes the shortcomings of the prior art, solves the problems of difficult mud ball cleaning and low reliability during cleaning, and improves the reliability on the basis of simplifying the structure and achieves very excellent mud ball cleaning effect under pressure less than that during drilling.

[0008] The utility model discloses a flushing mechanism for drill bit mud ball, which overcomes the shortcomings of the prior art, solves the problems of difficult mud ball cleaning and low reliability during cleaning, and improves the reliability on the basis of simplifying the structure and achieves very excellent mud ball cleaning effect under pressure less than that during drilling.

[0009] The wall of the central cavity is provided with a flushing channel, the outlet of the flushing channel corresponds to the drill bit chip groove, and the inlet of the flushing channel is located at the inner wall of the central cavity.

[0010] Further comprising:

[0011] The fixing member is fixed in the central cavity.

[0012] The fixing member cuts off the central cavity, and a first main hole is formed in the fixing member.

[0013] The fixing member and the inner wall of the central cavity form a slot, the fixing member is provided with a first side hole at the slot, and the first side hole is opposite to the inlet of the flushing channel.

[0014] The movable member is arranged in the central cavity in an axially telescopic manner through the elastic assembly and cuts off the central cavity.

[0015] The movable member has an insertion part provided with a second side hole, and the insertion part extends into the slot; when the movable member moves axially, the first side hole, the second side hole, and the inlet of the flushing channel are connected; when the movable member moves axially, the insertion part cuts off the first side hole and the inlet of the flushing channel.

[0016] The movable member has a plug part, and the movable member is further provided with a second main hole; when the movable member moves axially, the plug part blocks the first main hole; when the movable member moves axially, the plug part is in an unblocked state with the first main hole, and the central cavity is connected through the first main hole and the second main hole.

[0017] As a preferred technical scheme of the present application, the central cavity is provided with the movable member below the fixing member, and the upper inlet of the central cavity is connected with drilling fluid. When the drilling fluid reaches the set pressure value, the plug part is pushed away from the first main hole, and the drilling fluid flows into the inner hole of the drill bit through the first main hole and the second main hole. When the drilling fluid decreases to the set pressure value, the plug part is blocked against the first main hole, and the first side hole, the second side hole, and the inlet of the flushing channel are aligned, so that the drilling fluid flushes the drill bit chip groove through the outlet of the flushing channel.

[0018] Further, the fixing member is a downwardly recessed barrel; the upper outer cylindrical surface of the fixing member has an annular protrusion which is threadedly matched with the inner wall of the central cavity; the lower part of the fixing member forms an annular-shaped insertion slot with the central cavity. The bottom of the recessed position of the fixing member is provided with a first main hole, and the sidewall of the recessed position of the fixing member is provided with a first side hole.

[0019] Further, the movable member is also a downwardly recessed barrel; the upper part of the movable member is an annular insertion part; the bottom center of the recessed position of the movable member has an upwardly protruding plug part, and the bottom of the recessed position of the movable member is also provided with a plurality of second main holes, and the sidewall of the recessed position of the movable member is provided with a plurality of second side holes; when liquid flows through the plurality of second main holes and the plurality of second side holes respectively, the flow rate of the liquid flowing through the plurality of second main holes is greater than the flow rate of the liquid flowing through the plurality of second side holes.

[0020] As a preferred technical solution of the present application, the elastic assembly includes a spring and a force receiving member, the force receiving member is fixed to the inner wall of the central cavity, and the two ends of the spring are respectively abutted against the force receiving member and the movable member.

[0021] As a preferred technical solution of the present application, the first main hole is a tapered hole with a small upper part and a large lower part, and the plug part is correspondingly tapered or spherical.

[0022] As a preferred technical solution of the present application, the drill bit is installed at the lower end surface of the flushing head, and the drill bit is in communication with the central cavity; when the drill bit is installed at the lower end of the flushing head, the outlets of some flushing channels are not aligned with the chip flute of the drill bit, the outlets of the flushing channels not aligned with the chip flute are plugged by threaded columns, and the outlets of the flushing channels aligned with the chip flute are threadedly installed with nozzles.

[0023] As a preferred technical solution of the present application, the first side hole and the second side hole are inclined from top to bottom and from inside to outside, and the upper section of the flushing channel has a corresponding inclined section; the diameters of the first side hole, the second side hole and the flushing channel are sequentially reduced.

[0024] Further, the movable member has an extension part which is attached to the force receiving member and between which a lower sealing ring is arranged; the extension part, the force receiving member and the central cavity form an annular cylindrical closed cavity, and the spring is located in the closed cavity.

[0025] In order to facilitate understanding, the working principle of the present scheme is described:

[0026] In normal drilling, the upper part of the central channel is connected to the large pressure drop (for example, 4 MPa) of the drill bit, at this time, the drilling fluid acts on the plug part to open the first main hole, and then the drilling fluid in the upper part of the central channel flows into the inner hole of the drill bit through the first main hole, the second main hole, and finally the flushing channel is closed, and then normal drilling is carried out (it should be noted that the cross-sectional area of the first main hole should be larger than the sum of the areas of all the second main holes, and when the drilling fluid acts on the movable part, a downward force is generated, and when the downward force is greater than the elastic force of the spring, the plug part and the first main hole are always in an open state);

[0027] When the drill bit is covered with a mud cake, the drilling fluid discharge is reduced to reduce the pressure drop of the drill bit (for example, reduced to 2 MPa), and then the downward pressure of the drilling fluid on the movable part is less than the elastic force of the spring, so that the movable part moves upward, and finally the plug part is closed against the first main hole; at this time, the movable part is connected to the first side hole through the second side hole and the inlet of the flushing channel when moving upward, so that the drilling fluid in the upper part of the central channel flows through the first side hole, the second side hole and the flushing channel, and the drilling fluid is sprayed to the mud cake in the drill bit to clean the mud cake;

[0028] It should be noted that the present scheme finds that when the mud cake in the drill bit is flushed, the drilling fluid does not need too much pressure to achieve good cleaning (without too much pressure, the drilling fluid for normal operation of the drill bit is reduced, for example, from 4 MPa to 2 MPa, which can also achieve cleaning).

[0029] The utility model has the following advantages:

[0030] (1) simple structure, long service life and high reliability;

[0031] (2) it is found that the mud cake can be removed by reducing the pressure of the drilling fluid, and the cleaning effect is very good. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 is a structure diagram of the plug part closing the first main hole in the utility model;

[0033] Figure 2 is a structure diagram of the plug part closing the first main hole in the utility model; Figure 1

[0034] Figure 3 is a structure diagram of the plug part closing the first main hole in the utility model;

[0035] Figure 4 is a structure diagram of the plug part closing the first main hole in the utility model; Figure 3

[0036] ​​In the diagram: 10-rinse head, 11-central cavity, 12-rinse channel, 13-nozzle;

[0037] 20-Fixing component, 21-First main hole, 22-First side hole, 23-Annular protrusion;

[0038] 30-slot;

[0039] 40-Moving part, 41-Insertion part, 42-Second side hole, 43-Plug head, 44-Second main hole, 45-Protrusion part;

[0040] 50 - Elastic component, 51 - Spring, 52 - Force-bearing component. Detailed Implementation

[0041] The present invention will be further described below with reference to the accompanying drawings, but the scope of protection of the present invention is not limited to the following description.

[0042] It should be noted that the orientation or positional relationship indicated by terms such as "left" and "right" is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the product of this utility model is usually placed in during use, or the orientation or positional relationship that is commonly understood by those skilled in the art. Such terms are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0043] It should be noted that, unless otherwise specified, the embodiments and features and technical solutions in the present invention can be combined with each other.

[0044] like Figures 1-4 As shown, a flushing mechanism for drill bit mud packing includes a flushing head 10 and a drill bit. The drill bit is installed at the lower end of the flushing head. A central cavity 11 is opened axially inside the flushing head 10, and the central cavity 11 is connected to the inner hole of the drill bit. Drilling fluid introduced through the central cavity 11 can be discharged from the inner hole of the drill bit.

[0045] A flushing channel 12 is provided on the wall of the central cavity 11. The outlet of the flushing channel 12 corresponds to the drill bit chip removal groove, while the inlet of the flushing channel 12 is located on the inner wall of the central cavity 11.

[0046] It also includes a fixing member 20 and a movable member 40. The fixing member 20 is fixedly installed in the central cavity 11, and the movable member 40 is installed in the central cavity 11 through the elastic component 50, which can extend and retract axially. Both the fixing member 20 and the movable member 40 cut off the central cavity 11.

[0047] Wherein, the fixed part 20 is provided with a first main hole 21 which penetrates through the fixed part 20 along the axial direction, and the fixed part 20 is provided with a first side hole 22, the entrance and exit of which are located at the upper surface and the outer surface of the fixed part 20 respectively;

[0048] Furthermore, a slot 30 is formed between the outer surface of the fixed part 20 and the inner wall of the central channel 11, and the movable part 40 is provided with an insertion part 41 which is inserted into the slot 30, and the insertion part 41 is provided with a second side hole 42, when the movable part 40 moves along the axial direction, the insertion part 41 moves up and down in the slot 30, and when it moves to a certain position, the second side hole 42 is opposite to the entrance of the first side hole 22 and the flushing channel 11, that is, the first side hole 22, the second side hole 42 and the entrance of the flushing channel 11 are communicated with each other;

[0049] Furthermore, the movable part 40 is provided with a plug part 43 which is opposite to the first main hole 21, when the movable part 40 moves along the axial direction, the plug part 43 can seal the first main hole 21 or the plug part 43 is separated from the first main hole 21, and the first main hole 21 is opened, and the movable part 40 is provided with a plurality of second main holes 44 which penetrate through the movable part 40 along the axial direction;

[0050] Furthermore, the movable part 40 is arranged below the fixed part 20 in the central channel 11;

[0051] When the drill bit works normally, the drilling fluid with a certain pressure value (the pressure value is required for normal drilling, for example, 4MPa) is introduced into the entrance of the central channel 11, the drilling fluid pushes the plug part 43 away from the first main hole 21, and the drilling fluid acts on the movable part 40 (the cross-sectional area of the first main hole 21 is larger than the sum of the cross-sectional areas of all the second main holes 44), and a downward pressure is generated, which overcomes the elastic force of the elastic assembly 50, and then the drilling fluid flows downward through the first main hole 21 and the second main holes 44 to the inner control of the drill bit;

[0052] When the bit has a ball up and the ball up needs to be cleaned, the drilling fluid pressure value at the upper part of the central channel 11 is reduced (it can be adjusted on the ground, adjusting the drilling fluid pressure is the prior art, for example, it can be adjusted to 2MPa), so that the downward pressure of the drilling fluid on the movable part 40 is not enough to overcome the elastic force of the elastic assembly 50, so that the movable part 40 acts upward, and then the plug part 43 blocks the first main hole 21; At this time, the second side hole 42 on the movable part 40 aligns the first side hole 22 with the flushing channel 12 in position - the three are in communication, so that the drilling fluid in the upper part of the central channel 11 flows into the flushing channel 12, and the drilling fluid at the outlet of the flushing channel 12 cleans the ball up at the flute of the bit, which can clean the ball up at the flute; After a period of time, the bit is rotated again, which can remove part of the ball up on the bit teeth; After a period of time, the bit is rotated again, and even under the action of smaller drilling fluid, the ball up of the bit can still be cleaned well, and the cleaning effect is good.

[0053] The structure of the cementing part 20 will be further described below.

[0054] As shown in Figures 1-4 , the fixed part 20 is a downwardly recessed barrel, and the upper part of the fixed part 20 has an annular protrusion 23; When installed, the annular protrusion 23 is threaded with the inner wall of the central channel 11, and the lower part of the fixed part 20 forms an annular slot 30 with the central channel 11.

[0055] In addition, the bottom of the recessed position of the fixed part 20 is provided with a first main hole, and the sidewall of the recessed position of the fixed part 20 is provided with a first side hole 22.

[0056] The structure of the movable part 40 will be further described below.

[0057] As shown in Figures 1-4 , the movable part 40 is also a downwardly recessed barrel, and the upper part of the movable part 40 is an annular insertion part 45, and the sidewall of the insertion part is provided with a second side hole 42;

[0058] In addition, the bottom center of the recessed part of the movable part 40 has an upwardly protruding plug part 43; and a plurality of second main holes 44 are also provided at the bottom of the recessed part of the movable part 40.

[0059] When the liquid flows through the plurality of second main holes 44 and the plurality of second side holes 42 respectively, the flow rate of the liquid flowing through the plurality of second main holes 44 is greater than the flow rate of the liquid flowing through the plurality of second side holes 42.

[0060] The elastic assembly 50 will be further described below.

[0061] The elastic assembly 50 comprises a spring 51 and a force receiving member 52 fixed to the inner wall of the central cavity 11, and the two ends of the spring 51 are respectively abutted against the force receiving member 52 and the movable member 40.

[0062] Further, the movable member 40 has an extension 45 abutting against the force receiving member 52 and provided with a lower sealing ring therebetween, and the extension 45, the force receiving member 52 and the central cavity form an annular cylindrical closed cavity in which the spring 51 is located.

[0063] Optionally, in the embodiment, the first main hole 21 is a tapered hole with a small upper end and a large lower end, and the plug portion 43 is correspondingly tapered or spherical.

[0064] Optionally, in the embodiment, the drill bit is installed at the lower end face of the flushing head and communicates with the central cavity 11, and when the drill bit is installed at the lower end of the flushing head, the outlets of some of the flushing channels 12 are not aligned with the chip groove of the drill bit, the outlets of the flushing channels 12 not aligned with the chip groove are plugged by threaded columns, and the outlets of the flushing channels 12 aligned with the chip groove are provided with the nozzles 13 threaded.

[0065] Optionally, in the embodiment, the first side hole 22 and the second side hole 42 are inclined from top to bottom and from inside to outside, and the upper section of the flushing channel 12 has a corresponding inclined section, and the diameters of the first side hole 22, the second side hole 42 and the flushing channel 12 are sequentially reduced.

[0066] The above embodiments only express the preferred embodiments, and the description is more specific and detailed, but it cannot be understood as the limitation of the scope of the utility model patent. It should be pointed out that for ordinary skilled persons in the art, without departing from the concept of the utility model, a number of modifications and improvements can be made, which belong to the protection scope of the utility model.

Claims

1. A flushing mechanism for drill bit mud packs, characterized in that: include: A flushing head (10) is provided between the drill pipe and the drill bit in an oil and gas well, and has a central cavity (11) that connects the drill pipe and the drill bit. The central cavity (11) has a flushing channel (12) on its wall. The outlet of the flushing channel (12) corresponds to the drill bit chip removal groove, and the inlet of the flushing channel (12) is located on the inner wall of the central cavity (11). The fastener (20) is fixed inside the central cavity (11); The fixing member (20) cuts off the central cavity (11), and a first main hole (21) is opened through the fixing member (20). A slot (30) is formed between the fixing member (20) and the inner wall of the central cavity (11). The fixing member (20) has a first side hole (22) at the slot (30). The first side hole (22) is opposite to the inlet position of the flushing channel (12). The movable part (40) is axially telescopically disposed within the central cavity (11) via the elastic component (50), which cuts off the central cavity (11); The movable part (40) has an insertion part (41) with a second side hole (42) on the insertion part (41), and the insertion part (41) extends into the slot (30); when the movable part (40) moves axially, it can connect the inlet of the first side hole (22), the second side hole (42), and the flushing channel (12); when the movable part (40) moves axially, it can cut off the inlet of the first side hole (22) and the flushing channel (12). The movable part (40) has a plug head (43) and a through second main hole (44) on the movable part (40); when the movable part (40) moves along the axial direction, the plug head (43) can block the first main hole (21); when the movable part (40) moves along the axial direction, the plug head (43) and the first main hole (21) can be in an unblocked state, and at this time the central cavity (11) passes through the first main hole (21) and the second main hole (44).

2. The flushing mechanism for drill bit mud packs according to claim 1, characterized in that: Inside the central cavity (11), a movable part (40) is provided below the fixed part (20). Drilling fluid is introduced into the upper inlet of the central cavity (11); When the drilling fluid reaches the set pressure value, the plug (43) is pushed open from the first main hole (21), allowing the drilling fluid to flow through the first main hole (21) and the second main hole (44) into the inner hole of the drill bit; When the drilling fluid decreases to the set pressure value, the plug head (43) blocks the first main hole (21). At this time, the inlets of the first side hole (22), the second side hole (42), and the flushing channel (12) are aligned with each other, and the drilling fluid is flushed at the drill bit chip removal groove through the outlet of the flushing channel (12).

3. The flushing mechanism for drill bit mud packs according to claim 2, characterized in that: The fastener (20) is a downwardly recessed barrel shape; The upper outer cylindrical surface of the fastener (20) has an annular protrusion (23), which is threaded to fit the inner wall of the central cavity (11); the lower part of the fastener (20) forms an annular slot (30) with the central cavity (11). The bottom of the recessed position of the fastener (20) is provided with a first main hole, and the side wall of the recessed position of the fastener (20) is provided with a first side hole (22).

4. The flushing mechanism for drill bit mud packs according to claim 3, characterized in that: The movable part (40) is also in the shape of a downwardly concave barrel; The upper part of the movable part (40) is an annular insertion part (41). The recess of the movable part (40) has an upwardly protruding plug (43) at the bottom center. The bottom of the recess of the movable part (40) also has multiple second main holes (44) and multiple second side holes (42) on the side wall of the recess of the movable part (40). When liquid flows through the multiple second main holes (44) and the multiple second side holes (42) respectively, the flow rate of liquid flowing through the multiple second main holes (44) is greater than the flow rate flowing through the multiple second side holes (42).

5. The flushing mechanism for drill bit mud packs according to any one of claims 1 to 4, characterized in that: The elastic component (50) includes a spring (51) and a force-bearing component (52). The force-bearing component (52) is fixed to the inner wall of the central cavity (11), and the two ends of the spring (51) abut against the force-bearing component (52) and the movable component (40) respectively.

6. The flushing mechanism for drill bit mud packs according to claim 5, characterized in that: The movable part (40) has a protrusion (45), which fits against the force-bearing part (52) and a lower sealing ring is provided between them; The protrusion (45), the force-bearing member (52), and the central cavity form a closed annular cavity, and the spring (51) is located in the closed cavity.

7. The flushing mechanism for drill bit mud packs according to claim 1, characterized in that: The first main hole (21) is a conical hole with a smaller top and a larger bottom, and the plug head (43) is a corresponding conical head or spherical shape.

8. The flushing mechanism for drill bit mud packs according to claim 1, characterized in that: The drill bit is installed at the lower end face of the flushing head and is connected to the central cavity (11); When the drill bit is installed at the lower end of the flushing head, some of the outlets of the flushing channels (12) are not aligned with the chip removal groove of the drill bit. The outlets of the flushing channels (12) that are not aligned with the chip removal groove are sealed with threaded posts, while the outlets of the flushing channels (12) that are aligned with the chip removal groove are threaded with nozzles (13).

9. The flushing mechanism for drill bit mud packs according to claim 1, characterized in that: The first side hole (22) and the second side hole (42) are inclined from top to bottom and from inside to outside, and the upper section of the flushing channel (12) has a corresponding inclined section; The diameters of the first side hole (22), the second side hole (42), and the flushing channel (12) decrease sequentially.

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