CN102644660B - Slide bearing joint in well with adjustable wellhead - Google Patents

Abstract

The invention relates to an adjustable downhole sliding bearing joint at the wellhead, which belongs to the field of oil and gas drilling equipment. Lubricating layer, upper spring pin, lower spring pin, sliding bearing inner ring, sliding bearing outer ring, positioning baffle and locking screw. The lower part of the upper rotating shaft is provided with a liquid guiding hole, and the liquid guiding hole guides the drilling fluid flowing through the upper rotating shaft into the gap between the upper rotating shaft and the sleeve; the sliding sleeve is a stepped sleeve, There is an upper sealing groove and a lower sealing groove in the inner hole of the sleeve, and there is a gap between the inner diameter of the sliding sleeve and the outer diameter of the upper rotating shaft; the upper spring pin is used to position the outer ring of the sliding bearing before adjusting the bearing, and the lower spring pin is used for Position the plain bearing outer ring after adjusting the bearing. The invention reduces the time for adjusting or replacing the bearing joint, increases the continuous working time of the bearing in the well, and improves the working efficiency.

Description

A wellhead adjustable downhole sliding bearing joint

technical field

The invention relates to an adjustable wellhead sliding bearing joint, which belongs to the field of oil and gas drilling equipment.

Background technique

During the drilling process, the rotary shaft in the downhole tool often uses a radial bearing joint as a support to reduce frictional resistance during power transmission and keep the center position of the rotary shaft fixed. However, in practical applications, the premature failure of bearing joints is the main reason for the reduction of downhole tool life. At present, after the bearing joint fails, it is necessary to trip out the drill to replace the bearing joint or adjust the bearing joint, and then run down the drill again, which is time-consuming and labor-intensive. Therefore, it is necessary to improve its structure to reduce the time for replacing or adjusting the bearing joint.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art and provide an adjustable downhole sliding bearing joint at the wellhead. When a part of the self-lubricating layer of the bearing joint wears out and fails, the sliding bearing outer ring can be adjusted by pressing at the wellhead. position, so that it touches the unworn self-lubricating layer, and the sliding bearing joint can be adjusted without drilling, which can effectively improve drilling efficiency.

The technical scheme adopted in the present invention is: a wellhead adjustable downhole sliding bearing joint of the present invention, mainly composed of an upper rotating shaft, a housing, an upper sealing ring, a sliding sleeve, a lower sealing ring, a thrust sleeve, a spring, a lower rotating shaft, It is composed of self-lubricating layer, upper spring pin, lower spring pin, sliding bearing inner ring, sliding bearing outer ring, positioning baffle and locking screw. The upper rotating shaft is a hollow shaft connected with the lower rotating shaft through threads; the lower part of the upper rotating shaft is provided with a fluid guide hole, and the fluid guiding hole guides the drilling fluid flowing through the upper rotating shaft into the space between the upper rotating shaft and the sleeve In the gap; the lower end of the upper rotating shaft is provided with a boss to provide the initial pressure difference for the axial movement of the sliding sleeve; the sliding sleeve is a stepped sleeve, and the inner hole of the sliding sleeve is provided with an upper sealing groove and a lower The sealing groove is used to place the upper sealing ring and the lower sealing ring respectively. There is a gap between the inner diameter of the sliding sleeve and the outer diameter of the upper rotating shaft, and the gap R is 1-3mm; the sliding sleeve and the thrust sleeve are connected by threads; the thrust sleeve It is a threaded sleeve at the upper end; the self-lubricating layer is glass fiber reinforced plastic with polytetrafluoroethylene as an additive, embedded in the outer surface of the inner ring of the sliding bearing and arranged 4-6 along the axial direction; the upper spring The pin is used to position the outer ring of the sliding bearing before the bearing is adjusted, and the lower spring pin is used to position the outer ring of the sliding bearing after the bearing is adjusted; the positioning baffle is used to limit the axial direction of the outer ring of the sliding bearing during the crimping position, to prevent the lower spring pin from being cut off during lame pressing.

The present invention has the advantages of: 1. The relative position of the inner ring of the sliding bearing and the outer ring of the sliding bearing can be adjusted by means of lame pressure at the wellhead, and the adjustment process of the bearing joint is completed, which saves the process of tripping when adjusting the bearing joint; 2. 1. Reduce the time for adjusting or replacing the bearing joint; 3. Increase the time for the bearing joint to work continuously in the mine and improve work efficiency.

Description of drawings

Fig. 1 is a structural schematic diagram of an adjustable wellhead sliding bearing joint in the present invention.

Fig. 2 is a schematic diagram of the assembly of the sliding sleeve, the upper sealing ring and the lower sealing ring of the present invention.

FIG. 3 is a schematic cross-sectional view of A-A in FIG. 2 .

Fig. 4 is a half-sectional schematic diagram of the sliding sleeve of the present invention.

Fig. 5 is a schematic diagram of the housing structure of the present invention.

Fig. 6 is a schematic diagram of the relative positions of the upper spring pin, the lower spring pin and the housing before crimping according to the present invention.

In the figure: 1. Upper rotating shaft, 2. Housing, 3. Upper sealing ring, 4. Sliding sleeve, 5. Lower sealing ring, 6. Thrust sleeve, 7. Spring, 8. Lower rotating shaft, 9. Self-lubricating layer, 10. sliding bearing outer ring, 11. sliding bearing inner ring, 12. positioning baffle, 13. locking screw, 14. lower spring pin groove, 15. lower spring pin, 16. upper spring pin, 17. upper Spring pin groove, 18. boss, 19. liquid guide hole, 20. upper sealing groove, 21. lower sealing groove.

Detailed ways

The specific embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

As shown in Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5 and Fig. 6, a wellhead adjustable downhole sliding bearing joint of the present invention is mainly composed of an upper rotating shaft 1, a housing 2, an upper sealing ring 3, a sliding Cover 4, lower sealing ring 5, thrust sleeve 6, spring 7, lower rotating shaft 8, self-lubricating layer 9, sliding bearing outer ring 10, sliding bearing inner ring 11, positioning baffle 12, locking screw 13. The upper rotating shaft 1 is a hollow shaft connected with the lower rotating shaft 8 through threads; the lower part of the upper rotating shaft 1 is provided with a liquid guide hole 19, and the liquid guide hole 19 guides the drilling fluid flowing through the upper rotating shaft 1 into the upper In the gap between the rotating shaft 1 and the sleeve 4; the lower end of the upper rotating shaft 1 is provided with a boss 18 to provide an initial pressure difference for the movement of the sliding sleeve 4; as shown in Figure 2 and Figure 3, the sliding sleeve 4 is A stepped sleeve has an upper sealing groove 20 and a lower sealing groove 21 in the inner hole of the sliding sleeve 4, which are used to place the upper sealing ring 3 and the lower sealing ring 5 respectively. There is a gap in the outer diameter of the outer diameter, and the gap R is 1-3mm; the sliding sleeve 4 is set on the upper rotating shaft 1 and the lower rotating shaft 8, and the gap between the sliding sleeve 4 and the upper rotating shaft 1 is sealed by the upper sealing ring 3 Sealing, the gap between the sliding sleeve 4 and the lower rotating shaft 8 is sealed through the lower sealing ring 5, and the sliding sleeve 4 and the thrust sleeve 6 are connected by threads; the thrust sleeve 6 is a sleeve with threads on the upper end; The self-lubricating layer 9 is a glass fiber reinforced plastic with polytetrafluoroethylene as an additive, embedded in the outer surface of the sliding bearing inner ring 11 and arranged 4-6 along the axial direction; as shown in Figure 6, the upper spring pin 16 is used Position the outer ring 10 of the sliding bearing before adjusting the bearing, and the lower spring pin 15 is used to position the outer ring 10 of the sliding bearing after adjusting the bearing; the positioning baffle 12 is used to limit the axial direction of the outer ring 10 of the sliding bearing during the pressing process. position, to prevent the lower spring pin 15 from being cut off during the pressing process.

As shown in Figure 4, the inner wall of the housing is provided with an upper spring pin groove 17 and a lower spring pin groove 14, which are respectively used to position the sliding bearing outer ring 10 before adjusting the bearing and to position the sliding bearing outer ring 10 after adjusting the bearing. .

The working principle of a downhole sliding bearing joint with adjustable wellhead: when the bearing works normally, the resultant force of the drilling fluid flowing through the upper rotating shaft 1 acting on the sliding sleeve 4 along the axis through the fluid guide hole 19 is less than the specified Due to the elastic force of the spring 7, the sliding sleeve 4 is in close contact with the lower end surface of the boss 18 of the upper rotating shaft 1. The lower rotating shaft 8, the spring 7, the sliding sleeve 4, the thrust sleeve 6, the upper sealing ring 3, and the lower sealing ring 5 rotate together with the upper rotating shaft 1; the sliding bearing outer ring 10, the positioning baffle 12, and the housing 2 do not rotate . When the self-lubricating layer 9 of the sliding bearing joint is severely worn and is not enough to form a lubricating film, the annulus is closed at the wellhead, and the inner pressure of the drill string is carried out to make the drilling fluid pressure in the upper rotating shaft 1 exceed the pressure during normal drilling. The pressure acts on the sliding sleeve 4 through the liquid guide hole 19, so that the compression spring 7 of the sliding sleeve 4 moves downward along the upper rotating shaft 1 and the lower rotating shaft 8, and the sliding sleeve 4 drives the thrust sleeve 6 to move downward in the axial direction. When the lower end surface of the thrust sleeve 6 touches the outer ring of the sliding bearing 10, the pressing is continued, and the upper spring pin 16 is shortened to push the outer ring of the sliding bearing 10 to move downward along the axial direction of the housing 2. When the lower end surface of the sliding bearing outer ring 10 is attached to the positioning baffle 12, the lower spring pin 15 springs into the lower spring pin groove 14 on the inner wall of the housing 2. At this time, the sliding bearing outer ring 10 The unworn part of the self-lubricating layer 9 will be in contact. Open the annulus and end the lame pressure process. At this time, the resultant downward force of the drilling fluid acting on the sliding sleeve 4 along the axis is smaller than the upward elastic force provided by the spring 7 again, and the sliding sleeve 4 moves upward under the action of the spring 7 to drive the thrust. The sleeve 6 breaks away from the upper end surface of the sliding bearing outer ring 10, and the sliding sleeve 4 and the boss 18 of the upper rotating shaft 1 are fitted again, and the sliding bearing joint enters the normal working state again.

Claims (2)

1. An adjustable downhole sliding bearing joint at the wellhead, mainly composed of an upper rotating shaft (1), a housing (2), an upper sealing ring (3), a sliding sleeve (4), a lower sealing ring (5), and a thrust sleeve ( 6), spring (7), lower rotating shaft (8), self-lubricating layer (9), upper spring pin (16), lower spring pin (15), sliding bearing outer ring (10), sliding bearing inner ring (11 ), a positioning baffle (12), and a locking screw (13), and it is characterized in that: a fluid guide hole (19) is opened at the lower part of the upper rotating shaft (1), and the fluid guide hole (19) will flow through the upper The drilling fluid of the rotating shaft (1) is introduced into the gap between the upper rotating shaft (1) and the sleeve (4); a boss (18) is provided at the lower end of the upper rotating shaft (1) for the movement of the sliding sleeve (4) Provide an initial pressure difference; the sliding sleeve (4) is a stepped sleeve, and an upper sealing groove (20) and a lower sealing groove (21) are opened in the inner hole of the sliding sleeve (4), respectively for placing the upper There is a gap between the sealing ring (3) and the lower sealing ring (5), the inner diameter of the sliding sleeve (4) and the outer diameter of the upper rotating shaft (1), and the gap R is 1-3mm; the sliding sleeve (4) and the thrust sleeve ( 6) Threaded connection; the upper spring pin (16) is used to position the outer ring of the sliding bearing (10) before adjusting the bearing joint, and the lower spring pin (15) is used to position the outer ring of the sliding bearing (10) after adjusting the bearing joint ( 10) Positioning; the positioning baffle (12) is used to limit the axial position of the outer ring of the sliding bearing (10) in the process of crimping, and prevent the lower spring pin (15) from being cut off during the crimping; when the sliding bearing joint A part of the self-lubricating layer (9) is severely worn and is not enough to form a lubricating film. After the lower end surface of the thrust sleeve (6) touches the outer ring of the sliding bearing (10) through lame pressure, the lame pressure is continued, and the upper spring pin (16) is pressed After cutting, push the outer ring of the sliding bearing (10) to move downward along the axial direction of the housing (2) until the lower end surface of the outer ring of the sliding bearing (10) is attached to the positioning baffle (12), and the lower spring pin (15) slides in position Axial position of the bearing outer ring (10) where the plain bearing outer ring (10) contacts the unworn part of the self-lubricating layer (9). the 2. The wellhead adjustable downhole sliding bearing joint according to claim 1, characterized in that: the sliding sleeve (4) is sleeved on the upper rotating shaft (1) and the lower rotating shaft (8), and through the upper sealing The ring (3) seals the gap between the sliding sleeve (4) and the upper rotating shaft (1), and the lower sealing ring (5) seals the gap between the sliding sleeve (4) and the lower rotating shaft (8). the

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