An elastically supported jaw-engaging flexible joint

Abstract

The present invention provides an elastic support jaw-engaging flexible joint. The tail end of the upper joint is connected to the head end of the jaw-engaging rotating shaft. An outer cylinder is installed on the outer wall at the connection between the upper joint and the jaw-engaging rotating shaft. The inner spherical cylinder is installed in the space formed by the tail end of the upper joint and the head end of the jaw-engaging rotating shaft. An elastic support ring is installed on the inner wall at the connection between the upper joint and the jaw-engaging rotating shaft. The tail end of the jaw-engaging rotating shaft is connected to the head end of the lower joint. This flexible joint can not only achieve short-radius drilling but also effectively transmit the drilling pressure in the horizontal section.

Description

Technical Field

[0001] The present invention relates to the technical field of oil drilling, and more specifically to a resiliently supported jaw-engaged flexible joint. Background Art

[0002] In the middle and late stages of oilfield development, the demand for sidetracking low-yield and inefficient wells, sand-producing wells, water-flooded wells, etc. is increasing day by day. For conventional small-curvature and medium-curvature directional technologies, the new wellbore for sidetracking requires a relatively long section to deviate from the old wellbore. The new wellbore for sidetracking is greatly affected by the old wellbore. For example, in the case of a water-flooded well, the newly sidetracked well is quickly water-flooded, and the oil and gas production after sidetracking is poor. Short-radius horizontal wells can quickly deviate from the old wellbore and are less affected by the old wellbore. During the operation of short-radius horizontal wells, the build-up rate of conventional drill strings is much lower than the build-up rate required during short-radius drilling. To solve related problems, a flexible connection method is usually adopted to increase the build-up rate of the drill string. However, during horizontal section drilling, due to the large flexibility of the drill string, the transmission of the drilling pressure is uncertain due to the radial offset of the flexible drill string and cannot be effectively transmitted to the drill bit. Summary of the Invention

[0003] The present invention overcomes the deficiencies in the prior art, namely the problem of irregular radial offset during existing short-radius horizontal drilling, and provides a resiliently supported jaw-engaged flexible joint and its usage method. This flexible joint can not only achieve short-radius drilling but also effectively transmit the drilling pressure in the horizontal section.

[0004] The object of the present invention is achieved by the following technical solutions.

[0005] A resiliently supported jaw-engaged flexible joint, comprising an upper joint, an outer cylinder, an inner spherical cylinder, a resilient support ring, a jaw-engaged rotating shaft, and a lower joint. The tail end of the upper joint is connected to the head end of the jaw-engaged rotating shaft. The outer cylinder is installed on the outer wall at the connection of the upper joint and the jaw-engaged rotating shaft. The inner spherical cylinder is installed in the space formed by the tail end of the upper joint and the head end of the jaw-engaged rotating shaft. The resilient support ring is installed on the inner wall at the connection of the upper joint and the jaw-engaged rotating shaft. The tail end of the jaw-engaged rotating shaft is connected to the head end of the lower joint.

[0006] The inner wall of the head end of the upper joint adopts a female thread structure. The inner wall of the tail end of the upper joint forms a three-stage stepped structure. The outer wall of the tail end of the upper joint adopts a male thread structure. The tail end of the upper joint is alternately provided with plugging bosses. The inner wall of the middle section of the upper joint and the inner wall of the tail end of the upper joint are connected by a ramp structure.

[0007] The head end of the spline engagement type rotating shaft is staggeredly provided with insertion grooves, which are matched with the insertion bosses. The outer wall of the head end of the spline engagement type rotating shaft forms an upper stepped spherical surface and a lower stepped spherical surface, and the inner wall of the head end of the spline engagement type rotating shaft forms a limiting step. The outer wall of the tail end of the spline engagement type rotating shaft adopts a male thread structure, and the inner spherical surface cylinder is installed in the space formed by the upper stepped spherical surface and the inner wall of the upper joint.

[0008] The tail end of the inner spherical surface cylinder forms an inner spherical surface, which is matched with the upper stepped spherical surface.

[0009] The inner wall of the head end of the outer cylinder adopts a female thread structure. The inner wall of the middle part of the outer cylinder forms an outer cylinder inner spherical surface, which is matched with the lower stepped spherical surface. The tail end of the outer cylinder adopts an outward-opening flared structure.

[0010] The elastic support ring adopts an elastic steel material structure. The head and tail ends of the elastic support ring are respectively in contact with the first step of the three-stage stepped structure of the upper joint and the limiting step of the spline engagement type rotating shaft to achieve the purpose of restricting the axial movement of the elastic support ring. The outer diameter of the elastic support ring is less than or equal to the inner diameter of the space formed by the upper joint, the inner spherical surface cylinder and the spline engagement type rotating shaft.

[0011] Axial slits are evenly formed on the side wall of the elastic support ring along the axial direction of the elastic support ring.

[0012] The head end of the lower joint adopts a female thread structure, and the tail end of the lower joint adopts a male thread structure.

[0013] The beneficial effects of the present invention are as follows: The inner spherical surface cylinder of the flexible joint is the main load-bearing part and is independently designed, which is beneficial to later maintenance and replacement; the elastic support ring has an axial support effect on the flexible joint and can maintain the effective transmission of the drilling pressure. Brief Description of the Drawings

[0014] Figure 1 is a structural schematic diagram of the present invention;

[0015] Figure 2 is a three-dimensional structural schematic diagram of the spline engagement type rotating shaft member in the present invention;

[0016] Figure 3 is a three-dimensional structural schematic diagram of the upper joint member in the present invention;

[0017] In the figure: 1 is the upper joint, 2 is the outer cylinder, 3 is the inner spherical surface cylinder, 4 is the elastic support ring, 5 is the spline engagement type rotating shaft, and 6 is the lower joint.

[0018] For those of ordinary skill in the art, without creative efforts, other relevant drawings can be obtained based on the above drawings. Detailed implementation manners

[0019] The technical solution of the present invention will be further described below through specific embodiments.

[0020] Embodiment 1

[0021] An elastic support jaw-engaging flexible joint includes an upper joint 1, an outer cylinder 2, an inner spherical surface cylinder 3, an elastic support ring 4, a jaw-engaging rotating shaft 5, and a lower joint 6. The tail end of the upper joint 1 is connected to the head end of the jaw-engaging rotating shaft 5. The outer cylinder 2 is installed on the outer wall at the connection of the upper joint 1 and the jaw-engaging rotating shaft 5. The inner spherical surface cylinder 3 is installed in the space formed by the tail end of the upper joint 1 and the head end of the jaw-engaging rotating shaft 5. The elastic support ring 4 is installed on the inner wall at the connection of the upper joint 1 and the jaw-engaging rotating shaft 5. The tail end of the jaw-engaging rotating shaft 5 is connected to the head end of the lower joint 6.

[0022] Embodiment 2

[0023] On the basis of Embodiment 1, the inner wall of the head end of the upper joint 1 adopts a female thread structure. The inner wall of the tail end of the upper joint 1 forms a three-level stepped structure. The outer wall of the tail end of the upper joint 1 adopts a male thread structure. The tail end of the upper joint 1 is alternately provided with plug-in bosses. The inner wall of the middle section of the upper joint 1 and the inner wall of the tail end of the upper joint 1 are connected by a slope structure.

[0024] The head end of the jaw-engaging rotating shaft 5 is alternately provided with plug-in grooves, which cooperate with the plug-in bosses. The outer wall of the head end of the jaw-engaging rotating shaft 5 forms an upper stepped spherical surface and a lower stepped spherical surface. The inner wall of the head end of the jaw-engaging rotating shaft 5 forms a limiting step. The outer wall of the tail end of the jaw-engaging rotating shaft 5 adopts a male thread structure. The inner spherical surface cylinder 3 is installed in the space formed by the upper stepped spherical surface and the inner wall of the upper joint 1.

[0025] The tail end of the inner spherical surface cylinder 3 forms an inner spherical surface, which matches the upper stepped spherical surface.

[0026] The inner wall of the head end of the outer cylinder 2 adopts a female thread structure. The middle inner wall of the outer cylinder 2 forms an outer cylinder inner spherical surface, which matches the lower stepped spherical surface. The tail end of the outer cylinder 2 adopts an outward-opening flared structure.

[0027] Embodiment 3

[0028] On the basis of the second embodiment, the elastic support ring 4 adopts an elastic steel material structure. The head and tail ends of the elastic support ring 4 are respectively in contact with the first step of the three-level stepped structure of the upper joint 1 and the limit step of the spline engagement type rotating shaft 5, so as to achieve the purpose of restricting the axial movement of the elastic support ring 4. The outer diameter of the elastic support ring 4 is less than or equal to the inner diameter of the space formed by the upper joint 1, the inner spherical surface cylinder 3 and the spline engagement type rotating shaft 5.

[0029] Axial slits along the axis of the elastic support ring 4 are evenly formed on the side wall of the elastic support ring 4.

[0030] The head end of the lower joint 6 adopts a female thread structure, and the tail end of the lower joint 6 adopts a male thread structure.

[0031] For ease of explanation, spatial relative terms such as "upper", "lower", "left", and "right" are used in the embodiments to describe the relationship of one element or feature shown in the drawings relative to another element or feature. It should be understood that, in addition to the orientation shown in the drawings, the spatial terms are intended to include different orientations during the use or operation of the device. For example, if the device in the drawings is inverted, the element described as being "below" other elements or features will be positioned "above" the other elements or features. Therefore, the exemplary term "lower" can include both the upper and lower orientations. The device can be positioned in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein can be interpreted accordingly.

[0032] Moreover, relative relationship terms such as "first" and "second" are only used to distinguish one component with the same name from another, and do not necessarily require or imply any such actual relationship or order between these components.

[0033] The present invention has been described in detail above, but the above content is only the preferred embodiment of the present invention and cannot be considered as limiting the scope of implementation of the present invention. All equivalent changes and improvements made in accordance with the scope of the application of the present invention should still fall within the scope covered by the patent of the present invention.

Claims

1. An elastic support jaw-engaging flexible joint, characterized in that: It includes an upper joint, an outer cylinder, an inner spherical surface cylinder, an elastic support ring, a jaw coupling type rotating shaft and a lower joint. The tail end of the upper joint is connected to the head end of the jaw coupling type rotating shaft. The outer cylinder is installed on the outer wall at the connection of the upper joint and the jaw coupling type rotating shaft. The inner spherical surface cylinder is installed in the space formed by the tail end of the upper joint and the head end of the jaw coupling type rotating shaft. The elastic support ring is installed on the inner wall at the connection of the upper joint and the jaw coupling type rotating shaft. The tail end of the jaw coupling type rotating shaft is connected to the head end of the lower joint; The inner wall of the head end of the upper joint adopts a female thread structure. The inner wall of the tail end of the upper joint forms a three - stage stepped structure. The outer wall of the tail end of the upper joint adopts a male thread structure. The tail end of the upper joint is alternately provided with plugging bosses. The inner wall of the middle section of the upper joint and the inner wall of the tail end of the upper joint are connected by a slope structure; The head end of the jaw coupling type rotating shaft is alternately provided with plugging grooves which are matched with the plugging bosses. The outer wall of the head end of the jaw coupling type rotating shaft forms an upper stepped spherical surface and a lower stepped spherical surface. The inner wall of the head end of the jaw coupling type rotating shaft forms a limiting step. The outer wall of the tail end of the jaw coupling type rotating shaft adopts a male thread structure. The inner spherical surface cylinder is installed in the space formed by the upper stepped spherical surface and the inner wall of the upper joint.

2. The resiliently supported jaw-engaging flexible joint according to claim 1, wherein: The tail end of the inner spherical surface cylinder forms an inner spherical surface which is matched with the upper stepped spherical surface.

3. The elastic support jaw-engaging flexible joint according to claim 1, characterized in that: The inner wall of the head end of the outer cylinder adopts a female thread structure. The middle inner wall of the outer cylinder forms an inner spherical surface of the outer cylinder which is matched with the lower stepped spherical surface. The tail end of the outer cylinder adopts an outward - opening flared structure.

4. The resiliently supported jaw-engaging flexible joint according to claim 1, wherein: The elastic support ring adopts an elastic steel material structure. The head and tail ends of the elastic support ring are respectively in contact with the first - level step of the three - stage stepped structure of the upper joint and the limiting step of the jaw coupling type rotating shaft to achieve the purpose of restricting the axial movement of the elastic support ring. The outer diameter of the elastic support ring is less than or equal to the inner diameter of the space formed by the upper joint, the inner spherical surface cylinder and the jaw coupling type rotating shaft.

5. The elastic support jaw coupling type flexible joint according to claim 4, characterized in that: Axial slits are evenly opened on the side wall of the elastic support ring along the axial direction of the elastic support ring.

6. The elastic support type jaw coupling flexible joint according to claim 1, characterized in that: The head end of the lower joint adopts a female thread structure. The tail end of the lower joint adopts a male thread structure.

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