Mechanical rotary guiding system

Abstract

The utility model relates to the field of oil and gas well drilling, and discloses a mechanical rotary guide system which comprises a transmission shaft, one end of the transmission shaft is in threaded connection with a drill column, a shell is sleeved on the transmission shaft, and an upper bearing, a friction pair group I, a spacer bush, a friction pair group II and a lower bearing are sequentially sleeved on the transmission shaft and positioned in the shell. A first disc spring set is arranged between the first friction pair set and the second friction pair set and located between the spacer bush and the shell, the upper bearing is fixedly connected with the transmission shaft through a spline structure, the lower bearing is in threaded connection with the other end of the transmission shaft, the end, close to the lower bearing, of the shell is in threaded connection with a connector, and a counter bore is formed in the end, connected with the shell, of the connector. A thrust bearing is placed in the counter bore, a second disc spring set is arranged between the thrust bearing and the lower bearing, and the lower bearing is sleeved with the second disc spring set. According to the utility model, the effect that the upper drill stem still continuously rotates when the screw drill performs directional drilling can be realized, the frictional resistance is reduced, and the drilling efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the field of oil and gas drilling, in particular to a mechanical rotary steerable system. Background Art

[0002] In the process of oil and gas field development, it is necessary to drill various directional wells and horizontal wells, etc. During the directional deviation in conventional drilling, the drill string needs to be locked and not rotated, and only the downhole motor drill is retained for drilling. At this time, the friction of the drill string is large and the drilling efficiency is low. The conventional rotary steerable system adopts an electro-hydraulic integrated design, with extremely high processing and use costs and is not easy to promote and apply. Content of the Utility Model

[0003] In view of this, the purpose of the utility model is to provide a mechanical rotary steerable system to solve the problems pointed out in the above background art.

[0004] In order to achieve the above-mentioned utility model purpose, the following technical solutions are further adopted:

[0005] A mechanical rotary steerable system includes a transmission shaft, the transmission shaft is a hollow cylinder structure with threads processed at both ends, one end of the transmission shaft is threadedly connected to a drill string, a housing is sleeved on the transmission shaft, an upper bearing, a first friction pair group, a spacer sleeve, a second friction pair group and a lower bearing are sequentially sleeved on the transmission shaft and located inside the housing. A first disc spring group is arranged between the first friction pair group and the second friction pair group, and the first disc spring group is located between the spacer sleeve and the housing. The upper bearing is fixedly connected to the transmission shaft through a spline structure, the lower bearing is threadedly connected to the other end of the transmission shaft, one end of the housing close to the lower bearing is threadedly connected to a sub, a counterbore is arranged at the end of the sub connecting the housing, a thrust bearing is placed in the counterbore, and a second disc spring group is arranged between the thrust bearing and the lower bearing, and the second disc spring group is sleeved on the lower bearing.

[0006] As a further improvement of the utility model, the first friction pair group, the second friction pair group and the spacer sleeve are all circular ring structures.

[0007] As a further improvement of the utility model, both the first friction pair group and the second friction pair group include a plurality of friction pairs, each friction pair includes an inner friction plate and an outer friction plate, and the inner friction plates and the outer friction plates are arranged alternately.

[0008] As a further improvement of the utility model, both the upper bearing and the lower bearing are cylindrical sliding bearings.

[0009] As a further improvement of the utility model, the sub is a cylinder with external taper threads processed at both ends, one end of the sub is threadedly connected to the housing, and the other end is threadedly connected to a positive displacement motor.

[0010] The beneficial effects of the present utility model are as follows: The mechanical rotary steering system described in the present utility model, in cooperation with a wireless logging-while-drilling instrument, can achieve the functions of a conventional rotary steering system. By using a pure mechanical structure to achieve the function of controlling the directional orientation of the positive displacement motor in a conventional electro-mechanical-hydraulic integrated rotary steering drilling system, it can achieve the effect that the upper drill string continues to rotate during the directional drilling of the positive displacement motor, reducing the frictional resistance and improving the drilling efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The drawings forming a part of this application are used to provide a further understanding of the present utility model. The schematic embodiments and descriptions thereof of the present utility model are used to explain the present utility model and do not constitute an improper limitation to the present utility model. In the drawings:

[0012] Figure 1 is a schematic structural diagram of the present utility model;

[0013] Figure 2 is Figure 1 an enlarged view of the structure of part A of

[0014] Figure 3 is Figure 1 an enlarged view of the structure of part B of

[0015] In the figure: 1, transmission shaft; 2, housing; 3, upper bearing; 4, friction pair set one; 5, spacer sleeve; 6, disc spring set one; 7, friction pair set two; 8, lower bearing; 9, disc spring set two; 10, thrust bearing; 11, sub. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The present utility model will be described in detail below with reference to the drawings and in conjunction with the embodiments.

[0017] In order to enable those skilled in the art to better understand the solution of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of this application.

[0018] As Figures 1-3As shown in the figure, a mechanical rotary steerable system includes a drive shaft 1, which is a hollow cylindrical structure with threads machined at both ends. One end of the drive shaft 1 is threadedly connected to a drill string. A housing 2 is sleeved on the drive shaft 1. An upper bearing 3, a first friction pair group 4, a spacer sleeve 5, a second friction pair group 7, and a lower bearing 8 are sequentially sleeved on the drive shaft 1 inside the housing 2. A first disc spring group 6 is arranged between the first friction pair group 4 and the second friction pair group 7, and the first disc spring group 6 is located between the spacer sleeve 5 and the housing 2. The upper bearing 3 is fixedly connected to the drive shaft 1 through a spline structure. The lower bearing 8 is threadedly connected to the other end of the drive shaft 1. One end of the housing 2 near the lower bearing 8 is threadedly connected to a sub 11. A counterbore is provided at the end of the sub 11 where it connects to the housing 2. A thrust bearing 10 is placed in the counterbore, and a second disc spring group 9 is arranged between the thrust bearing 10 and the lower bearing 8, and the second disc spring group 9 is sleeved on the lower bearing 8.

[0019] Both the first friction pair group 4, the second friction pair group 7, and the spacer sleeve 5 are annular structures.

[0020] Both the first friction pair group 4 and the second friction pair group 7 include a plurality of friction pairs. Each friction pair includes an inner friction plate and an outer friction plate, and the inner friction plate and the outer friction plate are arranged alternately.

[0021] Both the upper bearing 3 and the lower bearing 8 are cylindrical sliding bearings.

[0022] The sub 11 is a cylinder with external taper threads machined at both ends. One end of the sub 11 is threadedly connected to the housing 2, and the other end is threadedly connected to a positive displacement motor.

[0023] During installation, the housing 2, the upper bearing 3, the first friction pair group 4, the spacer sleeve 5, the first disc spring group 6, the second friction pair group 7, and the lower bearing 8 are sequentially sleeved on the drive shaft 1. The lower bearing 8 is tightened with the drive shaft 1 by means of threaded connection. The second disc spring group 9 is sleeved on the lower bearing 8. The thrust bearing 10 is installed in the counterbore provided at one end of the sub 11 and pressed tightly by the second disc spring group 9. The sub 11 is tightened with the housing 2 by means of threaded connection.

[0024] During drilling, the drive shaft 1 of the steerable system is threadedly connected to the drill string inside, and the sub 11 is threadedly connected to the positive displacement motor outside. During drilling, the friction force of the friction pair is adjusted by adjusting the magnitude of the weight on bit applied to the drive shaft 1. Combining with the logging-while-drilling tool, the rotary steerable drilling effect of continuous rotation of the entire drill string above the steerable system can be achieved when the positive displacement motor drills in a certain direction, thereby reducing the drilling resistance and improving the drilling efficiency.

[0025] The above are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. For those skilled in the art, various modifications and variations can be made to the present utility model. Any modification, equivalent replacement, improvement, component disassembly or combination, etc., made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A mechanical rotary guide system, characterized in that: The invention comprises a transmission shaft, which is a hollow cylindrical structure with threads processed at both ends. One end of the transmission shaft is threadedly connected to a drill string. A shell is sleeved on the transmission shaft. An upper bearing, a friction pair group 1, a spacer sleeve, a friction pair group 2 and a lower bearing are sleeved on the transmission shaft and located inside the shell in sequence. A disc spring group 1 is arranged between the friction pair group 1 and the friction pair group 2, and the disc spring group 1 is located between the spacer sleeve and the shell. The upper bearing is fixedly connected to the transmission shaft through a spline structure. The lower bearing is threadedly connected to the other end of the transmission shaft. An end of the shell close to the lower bearing is threadedly connected to a joint. A countersunk hole is arranged at one end of the joint connected to the shell, and a thrust bearing is placed in the countersunk hole. A disc spring group 2 is arranged between the thrust bearing and the lower bearing, and the disc spring group 2 is sleeved on the lower bearing.

2. A mechanical rotary steerable system according to claim 1, characterized in that: The friction pair group 1, the friction pair group 2 and the spacer are all annular structures.

3. A mechanical rotary steerable system according to claim 2, characterized in that: The friction pair group 1 and the friction pair group 2 both include a plurality of friction pairs, and the friction pairs include inner friction plates and outer friction plates, and the inner friction plates and the outer friction plates are arranged alternately.

4. A mechanical rotary steerable system according to claim 1, characterized in that: The upper bearing and the lower bearing are both cylindrical sliding bearings.

5. The mechanical rotary steerable system according to claim 1, characterized in that: The joint is a cylinder with external conical threads processed at both ends. One end of the joint is threadedly connected to the shell body, and the other end is threadedly connected to the screw drill.

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