CN113123732A

CN113123732A - Casing centralizer

Info

Publication number: CN113123732A
Application number: CN201911419900.9A
Authority: CN
Inventors: 靳建洲; 王鹏; 李季; 王兆会; 刘斌辉
Original assignee: China National Petroleum Corp; CNPC Engineering Technology R&D Co Ltd
Current assignee: China National Petroleum Corp; CNPC Engineering Technology R&D Co Ltd
Priority date: 2019-12-31
Filing date: 2019-12-31
Publication date: 2021-07-16

Abstract

The present invention provides a casing centralizer. The casing centralizer includes: a pipe body; a plurality of centralizing strips are arranged on the outer surface of the pipe body, each centralizing strip extends along the axial direction and the radial direction of the pipe body, and the plurality of centralizing strips extend along the axial direction and the circumferential direction of the pipe body They are arranged at intervals; wherein, in any cross section, there is at most one righting strip; the cross section and the direction of the central axis of the pipe body are perpendicular to each other. The invention effectively solves the problems in the prior art that the casing is difficult to run due to the small annular flow area of the centralizer, and the labor intensity of the staff is increased.

Description

Casing centralizer

Technical Field

The invention relates to the technical field of petroleum drilling, in particular to a casing centralizer.

Background

At present, a rigid centralizer is a tool frequently used in well cementing and completion operations, and in order to keep a casing centered during casing running operations, a mode of adding the centralizer into a pipe string is generally adopted, and the rigid centralizer can keep the casing well centered.

However, when the casing is set in the small-gap well, the annular flow area of the centralizer is small due to the small gap between the pipe column and the well, so that the casing setting is difficult easily, and the labor intensity of workers is increased.

Disclosure of Invention

The invention mainly aims to provide a casing centralizer, and aims to solve the problems that casing running is difficult and the labor intensity of workers is increased due to the fact that the annular overflowing area of the centralizer is small in the prior art.

In order to achieve the above object, the present invention provides a casing centralizer comprising: a pipe body; the plurality of centralizing strips are arranged on the outer surface of the pipe body, each centralizing strip extends along the axial direction and the radial direction of the pipe body, and the plurality of centralizing strips are arranged at intervals along the axial direction and the circumferential direction of the pipe body; wherein, in any cross section, there is at most one righting strip; the cross section is perpendicular to the central axis direction of the tube body.

Further, the cross section of the centralizing strip is one or more of trapezoid, rectangle and square.

Further, along the extending direction of the centering strip, the centering strip comprises a first centering strip section and a second centering strip section connected with the first centering strip section, the cross-sectional area of at least part of the first centering strip section is gradually increased, and the cross-sectional area of at least part of the second centering strip section is gradually decreased.

Further, along the extending direction of the righting strip, the righting strip comprises a first righting strip section and a second righting strip section connected with the first righting strip section, the thickness of at least part of the first righting strip section is gradually increased, and the thickness of at least part of the second righting strip section is gradually reduced; wherein, the thickness direction of righting the strip is unanimous with the radial of body.

Further, along the axis direction of body, have the default clearance between every two adjacent righting strips.

Further, along the axis direction of body, the length that the clearance is less than righting the strip is predetermine.

Further, the centralizing strip and the pipe body are integrally formed.

Further, the first end of body has the external screw thread, and the second end of body has the internal thread, the both ends of body respectively with sleeve pipe threaded connection.

Further, a plurality of centralizing strips are arranged on the pipe body in a snake shape.

Furthermore, the surface of each righting strip, which is far away from the pipe body, is provided with a groove, and the extending direction of the righting strip is consistent with the extending direction of the groove.

Further, the rotation angle of each of the centering bars is not less than 20 ° and not more than 60 °.

By applying the technical scheme of the invention, the casing centralizer comprises a pipe body and a plurality of centralizing strips. A plurality of righting strips set up on the surface of body, and each righting strip is along the axial and the radial extension of body, and a plurality of righting strips set up along the axial and the circumference interval of body. Wherein, in any cross section, there is at most one righting strip; the cross section is perpendicular to the central axis direction of the tube body. Like this, above-mentioned setting guarantees to have at most one in same cross section and rights the strip, and then has increased the annular space overflow area of sleeve pipe centralizer for the lower casing pipe labour saving and time saving more has reduced the lower casing pipe degree of difficulty, and then has solved among the prior art because the annular space overflow area of centralizer is less and cause the lower casing pipe difficulty, has increased staff intensity of labour's problem, has reduced the probability of annular space jam.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 shows a partial cross-sectional view of an embodiment of a casing centralizer according to the present invention; and

fig. 2 shows an enlarged partial schematic view of the casing centralizer of fig. 1.

Wherein the figures include the following reference numerals:

10. a pipe body; 11. an external thread; 12. an internal thread; 20. a righting strip; 21. a first centralizer section; 22. a second centralizer section; 30. the gap is preset.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

It is noted that, unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

In the present invention, unless stated to the contrary, use of the directional terms "upper and lower" are generally directed to the orientation shown in the drawings, or to the vertical, or gravitational direction; likewise, for ease of understanding and description, "left and right" are generally to the left and right as shown in the drawings; "inner and outer" refer to the inner and outer relative to the profile of the respective member itself, but the above directional terms are not intended to limit the present invention.

In order to solve the problem that the annular flow area of the centralizer is small and the casing is difficult to descend and the labor intensity of workers is increased in the prior art, the application provides the casing centralizer.

As shown in fig. 1, the casing centralizer includes a tubular body 10 and a plurality of centralizer strips 20. Wherein, a plurality of righting strip 20 sets up on the surface of body 10, and each righting strip 20 extends along the axial and radial of body 10, and a plurality of righting strips 20 set up along the axial of body 10 and circumference interval. Wherein, in any cross-section, there is at most one righting strip 20; the cross section is perpendicular to the central axis of the tube 10.

With the technical solution of this embodiment, the casing centralizer includes a tubular body 10 and a plurality of centralizing bars 20. A plurality of the strips 20 are disposed on the outer surface of the tubular body 10, each strip 20 extends along the axial direction and the radial direction of the tubular body 10, and the strips 20 are disposed at intervals along the axial direction and the circumferential direction of the tubular body 10. Wherein, in any cross-section, there is at most one righting strip 20; the cross section is perpendicular to the axial direction of the pipe body 10. Like this, above-mentioned setting guarantees to have at most one righting strip 20 in same cross section, and then has increased the annular space overflow area of sleeve pipe centralizer for the lower casing pipe is labour saving and time saving more, has reduced the lower casing pipe degree of difficulty, and then has solved among the prior art because the annular space overflow area of centralizer is less and cause the lower casing pipe difficulty, has increased staff intensity of labour's problem, has reduced the probability of annular space jam.

Optionally, the cross-section of the centralizer strips 20 is one or more of trapezoidal, rectangular, square. As shown in fig. 2, the cross section of the centralizing strip 20 is trapezoidal, and the side of the trapezoid far away from the pipe body 10 is a short side, so that the casing resistance is reduced, the well fluid circulation capacity is improved, the casing running difficulty and the circulation blocking are avoided, the centralizing degree and the circulation displacement efficiency of the small well cementing casing are improved, and the well cementing quality is improved.

As shown in fig. 1, in the extending direction of the stabilizer bar 20, the stabilizer bar 20 includes a first stabilizer bar segment 21 and a second stabilizer bar segment 22 connected to the first stabilizer bar segment 21, at least a portion of the first stabilizer bar segment 21 has a gradually increasing thickness, and at least a portion of the second stabilizer bar segment 22 has a gradually decreasing thickness. Wherein, the thickness direction of the righting strip 20 is consistent with the radial direction of the pipe body 10. Like this, above-mentioned setting can further reduce the area of contact between sleeve pipe centralizer and the wall of a well, and then has reduced the frictional force between the two, guarantees that the sleeve pipe is gone into smoothly, has reduced staff's intensity of labour.

In other embodiments not shown in the drawings, the stabilizer bar comprises, in the direction of extension of the stabilizer bar, a first stabilizer bar section and a second stabilizer bar section connected to the first stabilizer bar section, at least part of the first stabilizer bar section having an increasing cross-sectional area and at least part of the second stabilizer bar section having a decreasing cross-sectional area. Like this, above-mentioned setting can further reduce the area of contact between sleeve pipe centralizer and the wall of a well, and then has reduced the frictional force between the two, guarantees that the sleeve pipe is gone into smoothly, has reduced staff's intensity of labour.

As shown in fig. 1, a predetermined gap 30 is formed between every two adjacent centering bars 20 along the axial direction of the pipe body 10. Like this, go into the in-process at the sleeve pipe, well liquid can flow in presetting clearance 30, and then has increased the annular space overflow area of sleeve pipe centralizer, avoids the sleeve pipe to go into the in-process and takes place the circulation to hold back stifled, has reduced the sleeve pipe and has gone into the difficulty degree, guarantees that the sleeve pipe goes into smoothly, has guaranteed the annular space overflow area of sleeve pipe centralizer furthest under the prerequisite of ensureing the sleeve pipe degree of centering, and then has promoted annular space gap fixed quality. Meanwhile, in the casing running process, the preset gap 30 can well fluid can be well fluid guided by the aid of the arrangement, and applicability of the casing centralizer in a small-gap well is improved.

In this embodiment, the predetermined gap 30 is smaller than the length of the stabilizer bar 20 along the axial direction of the tubular body 10. Therefore, the annular flow area of the casing centralizer is ensured to the maximum extent on the premise of ensuring the casing centering degree, the well fluid flow capacity can be effectively improved, the casing running difficulty is reduced, and the construction efficiency is improved.

Optionally, the centralizer strips 20 are integrally formed with the body 10. In this embodiment, a tube body with a larger thickness is cut to form the tube body 10 and the centering strip 20, so that on one hand, the machining of the casing centralizer is easier and simpler, and the machining difficulty is reduced; on the other hand, the overall structural strength of the casing centralizer is improved, and the service life of the casing centralizer is prolonged.

The machining method of the casing centralizer is not limited to this. Optionally, the casing centralizer is processed and manufactured by a cold rolling forming process, so that the processing precision of the casing centralizer is improved.

As shown in fig. 1, a first end of the pipe body 10 has an external thread 11, a second end of the pipe body 10 has an internal thread 12, and both ends of the pipe body 10 are respectively threadedly coupled to the sleeves. Specifically, a plurality of centering strips are located the middle part of body 10, the first end and a sleeve pipe threaded connection of body 10, the second end and another sleeve pipe threaded connection of body 10, and then make sleeve pipe centralizer and sheathed tube dismouting easier, simple and convenient, have reduced the dismouting degree of difficulty.

In this embodiment, the outer diameter of the pipe body 10 coincides with the outer diameter of the sleeve.

The structure of the pipe 10 is not limited to this. Optionally, the first end of the pipe 10 has an internal thread, the second end of the pipe 10 has an external thread, and both ends of the pipe 10 are respectively connected with the casing threads. Optionally, the first end of the tube 10 has an internal thread, the second end of the tube 10 has an internal thread, and both ends of the tube 10 are respectively connected with the casing threads. Optionally, the first end of the pipe 10 has an external thread, the second end of the pipe 10 has an external thread, and both ends of the pipe 10 are respectively connected with the casing threads.

As shown in fig. 1, a plurality of the centering bars 20 are arranged in a serpentine shape on the tube body 10. In this embodiment, the casing centralizer includes six righting strips 20, and six righting strips 20 are snakelike arranging on body 10, and the clearance 30 of predetermineeing between arbitrary two adjacent righting strips 20 in six righting strips 20 is equal, and then has promoted the water conservancy diversion effect of casing centralizer to well fluid, has reduced the sheathed tube degree of difficulty of going into.

The number of the centering bars 20 is not limited to this. Optionally, the number of the centering bars 20 is four, or five, or seven, or eight, or nine, which can be adjusted according to the length of the pipe 10.

Optionally, the surface of each of the centering bars 20 away from the tube body 10 has a groove, and the extending direction of the centering bars 20 is the same as the extending direction of the groove. Like this, go into the in-process under the sleeve pipe, the above-mentioned setting of recess can further accelerate the velocity of flow of well liquid on the sleeve pipe centralizer surface, and the recess still has good supplementary rectification effect.

Optionally, each centralizer strip 20 has a plurality of grooves thereon. Therefore, the well fluid flows in the grooves, the flow speed of the well fluid on the surface of the casing centralizer is further accelerated, and the well fluid blockage in a well hole is avoided.

Alternatively, the rotation angle of each of the stabilizer bars 20 is equal to or greater than 20 ° and equal to or less than 60 °. Thus, the parameter setting of the centering strip 20 furthest ensures the annular flow area of the casing centralizer on the premise of ensuring the casing centering degree, can effectively improve the well fluid circulation capacity, reduces the casing running difficulty and improves the construction efficiency. In the present embodiment, the rotation angle of each of the stabilizer bars 20 is 45 °.

In this embodiment, the centralizing strips 20 are distributed in a staggered manner according to a certain angle, so that the all-dimensional centralizing of the casing centralizer is realized.

From the above description, it can be seen that the above-described embodiments of the present invention achieve the following technical effects:

the casing centralizer includes a body and a plurality of righting strips. A plurality of righting strips set up on the surface of body, and each righting strip is along the axial and the radial extension of body, and a plurality of righting strips set up along the axial and the circumference interval of body. Wherein, in any cross section, there is at most one righting strip; the cross section is perpendicular to the axial direction of the tube body. Like this, above-mentioned setting guarantees to have at most one in same cross section and rights the strip, and then has increased the annular space overflow area of sleeve pipe centralizer for the lower casing pipe labour saving and time saving more has reduced the lower casing pipe degree of difficulty, and then has solved among the prior art because the annular space overflow area of centralizer is less and cause the lower casing pipe difficulty, has increased staff intensity of labour's problem, has reduced the probability of annular space jam.

It is to be understood that the above-described embodiments are only a few, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular is intended to include the plural unless the context clearly dictates otherwise, and it should be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of features, steps, operations, devices, components, and/or combinations thereof.

It should be noted that the terms "first," "second," and the like in the description and claims of this application and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are capable of operation in sequences other than those illustrated or described herein.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. a casing centralizer, is characterized in that, comprises:

pipe body (10);

A plurality of righting strips (20) are arranged on the outer surface of the pipe body (10), each of the righting strips (20) extends along the axial and radial directions of the pipe body (10), and a plurality of the The righting strips (20) are arranged at intervals along the axial and circumferential directions of the pipe body (10); wherein, in any cross section, there is at most one righting strip (20); the cross section and the pipe body The central axis directions of (10) are arranged perpendicular to each other.

2 . The casing centralizer according to claim 1 , wherein the cross section of the centralizing strip ( 20 ) is one or more of a trapezoid, a rectangle, and a square. 3 .

3. The casing centralizer according to claim 1, characterized in that, along the extending direction of the centralizing bar (20), the centralizing bar (20) comprises a first centralizing bar segment (21) and a In the second righting bar section (22) connected to the first righting bar section (21), the cross-sectional area of at least part of the first rightening bar section (21) is gradually increased, and at least part of the second rightening bar section (22) ) gradually decreases in cross-sectional area.

4. The casing centralizer according to claim 1, characterized in that, along the extending direction of the centralizing bar (20), the centralizing bar (20) comprises a first centralizing bar segment (21) and a The thickness of at least part of the first righting strip section (21) is gradually increased, and the thickness of at least part of the second righting strip section (22) is gradually increased. The thickness gradually decreases; wherein, the thickness direction of the righting strip (20) is consistent with the radial direction of the pipe body (10).

5. The casing centralizer according to claim 1, characterized in that, along the axial direction of the pipe body (10), there is a preset gap ( 30).

6 . The casing centralizer according to claim 5 , characterized in that, along the axial direction of the pipe body ( 10 ), the preset gap ( 30 ) is smaller than the length of the centralizing strip ( 20 ). 7 .

7 . The casing centralizer according to claim 1 , wherein the centralizing strip ( 20 ) is integrally formed with the pipe body ( 10 ). 8 .

8. The casing centralizer according to claim 1, wherein the first end of the pipe body (10) has an external thread (11), and the second end of the pipe body (10) has an internal thread (12), the two ends of the pipe body (10) are respectively connected with the casing threadedly.

9 . The casing centralizer according to claim 1 , wherein a plurality of the centralizing strips ( 20 ) are arranged in a serpentine shape on the pipe body ( 10 ). 10 .

10. The casing centralizer according to claim 1, characterized in that, the surface of each of the centralizing strips (20) away from the pipe body (10) has grooves, and the extending direction of the centralizing strips (20) Consistent with the extending direction of the groove.

11. The casing centralizer according to claim 1, wherein the rotation angle of each of the centralizing strips (20) is greater than or equal to 20° and less than or equal to 60°.