CN220226753U

CN220226753U - Eccentric centralizer

Info

Publication number: CN220226753U
Application number: CN202322003900.9U
Authority: CN
Inventors: 黄勇; 黄建军; 冯林林
Original assignee: GUANGHAN PETROLEUM WELL-CONTROL EQUIPMENT CO LTD
Current assignee: GUANGHAN PETROLEUM WELL-CONTROL EQUIPMENT CO LTD
Priority date: 2023-07-28
Filing date: 2023-07-28
Publication date: 2023-12-22
Anticipated expiration: 2033-07-28

Abstract

The utility model relates to the technical field of centralizers, in particular to an eccentric centralizer, wherein a working surface of a centralizing edge is provided with a plurality of embedded holes and wear-resistant alloy columns corresponding to the embedded holes one by one; the centering ribs are arranged along the circumferential direction of the mandrel and form an eccentric structure; and an embedded groove is further formed in the embedded hole, and the wear-resistant alloy column is embedded into the embedded hole and the bottom of the wear-resistant alloy column is connected with the embedded groove. Through this eccentric centralizer, the rotation of drilling string when can utilizing to bore carries out the reaming to the reducing well section, utilizes rotatory centrifugal force that produces to compact mud cake simultaneously, controls the wall of a well degree of narrowing, reduces the drilling fluid loss, can play the effect that reduces to play the drilling and hinder the card down, also can solve the problem that wear-resisting alloy post drops easily simultaneously.

Description

Eccentric centralizer

Technical Field

The utility model relates to the technical field of centralizers, in particular to an eccentric centralizer.

Background

In the oilfield drilling process, the centralizer is an important component of a lower drilling tool structure, can keep the well diameter and the well wall smooth, reduces the abrasion of the well wall to the drilling tool, and plays roles of inclination prevention, inclination correction and inclination stabilization respectively according to different positions of the centralizer in a drill string. To maintain wellbore size, wellbore wall stability, and kick off requirements, centralizers are required to be attached to the drill string during drilling operations. When a few kilometers of drilling tools work in a well, the drilling tools cannot freely move due to the reasons of shrinkage, deformation and the like of the well bores, and cannot lift, drop or rotate, so that the drilling tools are the most common and most easily-occurring underground engineering accidents in drilling operation, the drilling construction period is prolonged, and the operation cost is increased.

In the prior art, a Chinese patent document with publication number of CN202810657U and publication date of 2013, 03 and 20 is proposed to solve the above technical problems, and the technical scheme disclosed in the patent document is as follows: the utility model provides a spiral reaming hole expanding tool, the upper joint of this instrument, go up spiral centralizer, spiral centralizer down, connect integrated into one piece down and open at its center has the water eye, it has stress groove to process between spiral centralizer and the spiral centralizer down to go up, it has spiral working tape to process on the surface of spiral centralizer and the spiral centralizer down, PDC composite sheet has been inlayed at spiral working tape upper and lower both ends, it has wear-resisting alloy post to inlay uniformly on the working face of spiral working tape.

According to the technical scheme, in the actual use process, although the reaming of a certain degree can be realized, the stress of the centralizer is too concentrated in the drilling process, mud cakes cannot be compacted, the well wall has poor reduction effect, and the wear-resistant alloy column is easy to fall off.

Disclosure of Invention

In order to solve the technical problems, the utility model provides the eccentric centralizer, which can utilize the rotation of a drill stem during drilling to expand a diameter-reduced well section, simultaneously utilize the centrifugal force generated by rotation to compact mud cakes, control the reduction degree of a well wall, reduce the filtration of drilling fluid, not only play a role of reducing the action of drilling resistance card, but also solve the problem that the wear-resistant alloy column is easy to fall off.

The utility model is realized by adopting the following technical scheme:

an eccentric centralizer comprises a mandrel and a plurality of centralizing ribs arranged outside the mandrel, wherein a working surface of each centralizing rib is provided with a plurality of embedded holes and wear-resistant alloy columns corresponding to the embedded holes one by one; the centering ribs are arranged along the circumferential direction of the mandrel and form an eccentric structure; and an embedded groove is further formed in the embedded hole, and the wear-resistant alloy column is embedded into the embedded hole and the bottom of the wear-resistant alloy column is connected with the embedded groove.

The number of the righting edges is three, the righting edges sequentially comprise a first righting edge, a second righting edge and a third righting edge, and the central angle formed by the encircling of the first righting edge and the third righting edge is 180 degrees on the same horizontal plane.

Welding rods are further arranged at the upper end and the lower end of the righting edge.

The section of the embedded groove is in an inverted T shape or a dovetail groove shape.

And the working surface of the righting edge is also welded with a plurality of cemented carbide teeth, and the height of the welded cemented carbide teeth is higher than that of the working surface of the righting edge.

The hard alloy teeth are arranged in a row and are arranged on the edge line of the working surface of the righting edge.

The height of the installed wear-resistant alloy column is the same as the height of the working surface of the righting edge.

Compared with the prior art, the utility model has the beneficial effects that:

1. in the utility model, due to the eccentric arrangement of the centralizing edges, the integral centralizing device is of an eccentric structure, during the initial stage of shale diameter reduction or mud cake formation, the rotation of the drill stem during drilling can be utilized to expand the diameter-reduced well section, and meanwhile, the mud cake is compacted by the centrifugal force generated by rotation, so that the reduction degree of the well wall can be controlled, the drilling fluid loss is reduced, and the effect of reducing the drill-down blocking is achieved.

Furthermore, in the utility model, the wear-resistant alloy column is embedded into the embedded hole, and the bottom of the wear-resistant alloy column is connected with the embedded groove.

2. The central angle formed by the encircling of the first righting edge and the third righting edge is 180 degrees, so that the gravity center of the centralizer always faces the direction of the second righting edge, and the centralizer can always be in an eccentric state in the use process and can correct the well wall at any time.

3. Welding rods are further arranged at the upper end and the lower end of the righting edge, so that the wear resistance of the righting edge can be enhanced conveniently.

4. The cross section of the embedded groove is in an inverted T shape or a dovetail groove shape, so that the embedded groove is connected with the wear-resistant alloy column more stably.

5. The height of the cemented carbide teeth after the insert welding is higher than the height of the working surface of the righting edge, so that the cemented carbide teeth can generate good cutting action, and the reduction is convenient to further eliminate, and the well wall is trimmed.

6. The hard alloy teeth are arranged on the edge line of the working face of the righting edge, so that the hard alloy teeth can be repaired or replaced better.

7. The height of the installed wear-resistant alloy column is the same as the height of the working surface of the righting edge, so that the wear-resistant alloy column does not generate cutting force, the fracture probability of the wear-resistant alloy column is reduced, and the service life of the wear-resistant alloy column is prolonged.

Drawings

The utility model will be described in further detail with reference to the drawings and detailed description, wherein:

FIG. 1 is a schematic diagram of the structure of the present utility model;

FIG. 2 is a schematic cross-sectional view of A-A of the present utility model;

FIG. 3 is a schematic plan view of a righting rib according to the present utility model;

FIG. 4 is a schematic cross-sectional view of B-B according to the present utility model;

FIG. 5 is an enlarged view of the area C according to the present utility model;

the marks in the figure:

1. the wear-resistant alloy comprises a mandrel, 2, a wear-resistant alloy column, 3, an embedded groove, 4, a first righting edge, 5, a second righting edge, 6, a third righting edge, 7, a welding rod, 8 and cemented carbide teeth.

Detailed Description

Example 1

As a basic implementation mode of the utility model, the utility model comprises an eccentric centralizer, which comprises a mandrel 1 and a plurality of centralizing edges arranged outside the mandrel 1, wherein the working surface of each centralizing edge is provided with a plurality of embedded holes and wear-resistant alloy columns 2 corresponding to the embedded holes one by one. The righting edges are arranged along the circumferential direction of the mandrel 1 and form an eccentric structure. The specific structure of the centering ribs is not limited in this embodiment, as long as the centering device is finally formed into an eccentric structure. The embedded hole is internally provided with an embedded groove 3, the wear-resistant alloy column 2 is embedded into the embedded hole, the bottom of the wear-resistant alloy column is connected with the embedded groove 3, and the stability of connection of the wear-resistant alloy column 2 is conveniently increased.

Example 2

As a preferred embodiment of the utility model, the utility model comprises an eccentric centralizer, which comprises a mandrel 1 and three centralizing edges arranged outside the mandrel 1, and sequentially comprises a first centralizing edge 4, a second centralizing edge 5 and a third centralizing edge 6. The righting edges are arranged along the circumferential direction of the mandrel 1 and form an eccentric structure. Specifically, the cambered surface of the first righting edge 4 is wider, and the corresponding central angle is larger than the central angle corresponding to the second righting edge 5 and is also larger than the central angle corresponding to the third righting edge 6. Or, the arc widths of the three righting edges are the same, and on the same horizontal plane, at most, only one central angle formed by the encircling of the two adjacent righting edges is 120 degrees, namely, the distances between the three righting edges on the same horizontal plane are different, so that the righting edges are unevenly arranged.

And a plurality of embedded holes and wear-resistant alloy columns 2 corresponding to the embedded holes one by one are arranged on the working surface of the righting edge. In order to improve the stability of the connection of the wear-resistant alloy column 2, an embedded groove 3 is further arranged in the embedded hole, and the wear-resistant alloy column 2 is embedded in the embedded hole and the bottom of the wear-resistant alloy column is connected with the embedded groove 3.

The working face of the righting edge is welded with a plurality of cemented carbide teeth 8, and the height of the cemented carbide teeth 8 after welding is higher than that of the working face of the righting edge. The top of the hard alloy tooth 8 is provided with an inclined cutting edge, and the installation direction of the cutting edge is the circumferential cutting direction of the centralizer. The present embodiment is not limited to the specific position of the cemented carbide pieces 8, and may be disposed on the working surface of the righting rib in a dispersed manner or may be disposed on the working surface of the righting rib in a row. For ease of replacement, the cemented carbide pieces 8 may be arranged on both sides or on one of the sides of the working surface of the righting rib, such that the wear resistant alloy post 2 is located between two rows of cemented carbide pieces 8 or on one side of a row of cemented carbide pieces 8.

Example 3

As another preferred embodiment of the utility model, the utility model comprises an eccentric centralizer, which comprises a mandrel 1 and a plurality of centralizing edges arranged outside the mandrel 1, wherein the working surface of the centralizing edges is provided with a plurality of embedded holes and wear-resistant alloy columns 2 which are in one-to-one correspondence with the embedded holes. The upper end and the lower end of the righting edge are also provided with welding rods 7.

Wherein, the righting edge is arranged along the circumference of the mandrel 1 and forms an eccentric structure. Specifically, the number of the righting edges can be two, and the central angle formed by the centers of the two righting edges can be 90 degrees on the same horizontal plane.

The embedded hole is internally provided with an embedded groove 3, the section of the embedded groove 3 is in a dovetail groove shape, and the shape and the size of the bottom of the wear-resistant alloy column 2 are matched with those of the embedded groove 3, so that the wear-resistant alloy column 2 can be embedded into the embedded hole, the bottom of the wear-resistant alloy column is connected with the embedded groove 3, and the height of the embedded wear-resistant alloy column 2 is higher than that of a working surface of a righting edge.

In order to further improve the setting capacity of the well wall, the working face of the righting edge is welded with a plurality of cemented carbide teeth 8 in an embedded mode, and the height of the cemented carbide teeth 8 after embedded welding is higher than that of the working face of the righting edge. The cemented carbide teeth 8 may be arranged on two edge lines of the working surface of the righting edge.

Example 4

As the best mode of the utility model, the utility model comprises an eccentric centralizer, and referring to fig. 1 and 2 of the specification, the eccentric centralizer comprises a mandrel 1 and three righting edges arranged outside the mandrel 1, and sequentially comprises a first righting edge 4, a second righting edge 5 and a third righting edge 6. The three righting edges have the same structure, are integrally formed on the mandrel 1 in a spiral manner, and are arranged along the circumferential direction of the mandrel 1. On the same horizontal plane, the central angle formed by the enclosing of the first righting edge 4 and the third righting edge 6 is 180 degrees, and the central angle is formed by the enclosing of the central line of the first righting edge 4 and the central line of the third righting edge 6, or is formed by the enclosing of the front edge line of the first righting edge 4 and the front edge line of the third righting edge 6, or is formed by the enclosing of the rear edge line of the first righting edge 4 and the rear edge line of the third righting edge 6. The edge line which arrives first is a front edge line, and the edge line which arrives later is a rear edge line. Through the structural arrangement of the first righting edge 4 and the third righting edge 6, the gravity center direction always faces the direction of the second righting edge 5 no matter how the position of the second righting edge 5 is arranged, and the centralizer is always in an eccentric structure.

Further, the upper end and the lower end of each righting edge are also welded with welding rods 7, and referring to fig. 3 of the specification, a plurality of first embedded holes, second embedded holes, wear-resistant alloy columns 2 and hard alloy teeth 8 are further arranged on the working surface of each righting edge. The first inlay holes are used for installing the wear-resistant alloy columns 2, and the second inlay holes are used for installing the hard alloy teeth 8. The first mosaic holes and the second mosaic holes are respectively arranged in rows, and the second mosaic holes form a row and are arranged on the edge line of the working surface of the righting edge.

Referring to fig. 4 of the specification and fig. 5 of the specification, the first embedding hole is further provided with an inverted T-shaped embedding groove 3, the wear-resistant alloy column 2 may be a quincuncial tooth, and is made of YG20, and the shape and the size of the bottom of the wear-resistant alloy column 2 are matched with those of the embedding groove 3, so that the wear-resistant alloy column 2 can be embedded into the first embedding hole, the bottom of the wear-resistant alloy column 2 is connected with the embedding groove 3, and the height of the installed wear-resistant alloy column 2 is the same as the height of the working surface of the righting edge. The top of the hard alloy tooth 8 is provided with an inclined cutting edge, and the installation direction of the cutting edge is the circumferential cutting direction of the centralizer. The cemented carbide teeth 8 are welded in the second embedded holes, and the height of the welded cemented carbide teeth 8 is higher than the height of the working surface of the righting rib.

When the eccentric centralizer is used, the eccentric centralizer is connected with a lower drilling tool through a lower connector, an upper connector is connected with a drill string, and then the eccentric centralizer is used for well construction. In the initial stage of shale diameter reduction or mud cake formation, the rotation of the drill string during drilling is utilized, the eccentric centralizer expands the diameter reduction well section, meanwhile, the mud cake is compacted by utilizing the centrifugal force generated by rotation, the reduction degree of the well wall is controlled, the drilling fluid loss is reduced, the effect of reducing the tripping resistance card is achieved, and the probability of the PDC drill bit for early balling is effectively reduced. When a single scratch hole is drilled and the drill is started and started down shortly, the eccentric centralizer can be added, so that double trimming effect can be achieved on the well wall of the drilled section.

In view of the foregoing, it will be appreciated by those skilled in the art that, after reading the present specification, various other modifications can be made in accordance with the technical scheme and concepts of the present utility model without the need for creative mental efforts, and the modifications are within the scope of the present utility model.

Claims

1. An eccentric centralizer comprises a mandrel (1) and a plurality of centralizing edges arranged outside the mandrel (1), wherein a plurality of embedded holes and wear-resistant alloy columns (2) corresponding to the embedded holes one by one are arranged on the working surface of each centralizing edge; the method is characterized in that: the centering ribs are arranged along the circumferential direction of the mandrel (1) and form an eccentric structure; and an embedded groove (3) is further formed in the embedded hole, and the wear-resistant alloy column (2) is embedded into the embedded hole and the bottom of the wear-resistant alloy column is connected with the embedded groove (3).

2. An eccentric centralizer according to claim 1, wherein: the number of the righting edges is three, the righting edges sequentially comprise a first righting edge (4), a second righting edge (5) and a third righting edge (6), and the central angle formed by encircling the first righting edge (4) and the third righting edge (6) is 180 degrees on the same horizontal plane.

3. An eccentric centralizer according to claim 1 or 2, characterised in that: welding rods (7) are further arranged at the upper end and the lower end of the righting edge.

4. An eccentric centralizer according to claim 3, wherein: the section of the embedded groove (3) is in an inverted T shape or a dovetail groove shape.

5. An eccentric centralizer according to claim 4, wherein: and the working surface of the righting edge is also welded with a plurality of cemented carbide teeth (8), and the height of the welded cemented carbide teeth (8) is higher than that of the working surface of the righting edge.

6. An eccentric centralizer according to claim 5, wherein: the hard alloy teeth (8) are arranged in a row shape and are arranged on the edge line of the working surface of the righting edge.

7. An eccentric centralizer according to claim 1, wherein: the height of the installed wear-resistant alloy column (2) is the same as the height of the working surface of the righting edge.