CN110529074B - A drill bit synchronous rotating scraper - Google Patents

Abstract

The present invention discloses a drill synchronous rotating scraper, comprising a barrel, a plurality of mounting grooves are formed on the barrel wall of the barrel, a scraper plate is connected to the mounting groove through a first spring, a second spring with an elastic coefficient much larger than the first spring is also provided in the mounting groove, a movable plate is provided at the top of the second spring, the bottom of the first spring is installed on the movable plate, one end of the movable plate is connected to a linkage rod, the end of the linkage rod extends to the outside of the barrel, the linkage rod has a space for extending outward or contracting inward, and when the linkage rod extends outward, the movable plate moves radially outward along the barrel, and when the linkage rod contracts inward, the movable plate is driven to move radially inward along the barrel. The advantage of the present invention is that no matter how the actual inner diameter of the casing changes, the scraper plate can be scraped with an almost constant extrusion force, that is, it can avoid the scraper damage and drilling tool jamming caused by excessive scraping force, and can also avoid the poor cleaning effect caused by too small scraping force.

Description

A drill bit synchronous rotating scraper

Technical Field

The invention relates to the technical field of drilling equipment, and in particular to a drill bit synchronous rotating scraper.

Background technique

During the oilfield exploitation process, cement blocks, cement rings, hard wax, various salt crystals and sediments, perforation burrs, and iron oxide produced by casing corrosion often adhere to the inner barrel of the casing. Therefore, it is necessary to lower the scraper to clean the inner barrel of the casing that has been underground to improve the success rate of tool lowering and operation and keep the diameter of the casing unchanged. The scraper is usually used in conjunction with a screw motor. It is installed behind the drill bit and rotates synchronously with the drill bit. It cleans the inner wall of the casing during the drilling process, saving an extra tripping process.

The most common drill synchronous rotating scraper is the spring-type casing scraper, whose scraper plate is connected to the shell wall by a spring. When in use, the scraper plate expands outward and clings to the inner wall of the casing under the elastic extrusion of the spring to achieve scraping. This structure has a disadvantage: if the inner diameter of the casing is large, the spring is too elongated, resulting in insufficient elastic extrusion force provided by it, and the scraping effect is not ideal; if the inner diameter of the casing is small, the spring is too compressed, resulting in excessive elastic extrusion force provided by it, and long-term high-intensity scraping is easy to damage the scraper. In this case, if there is a section of the inner tube of the casing with thick cement blocks, various salt crystals and sediments, which makes the inner diameter of this section of the casing smaller, if the scraper is scraped directly under the action of the large elastic extrusion force, it is easy to cause damage to the scraper. If the sediment is hard, it may even cause the entire drill bit to get stuck and unable to rotate.

Although the inner diameter of the sleeve does not change much during normal use, due to the short length of the spring itself, a small change in the amplitude will also cause a large change in the spring elastic extrusion force. Therefore, this drawback cannot be ignored and needs to be solved urgently.

Summary of the invention

The object of the present invention is to provide a drill bit synchronous rotating scraper, which solves the problem that the elastic squeezing force of the spring in the traditional spring type casing scraper changes with the inner diameter of the casing, resulting in scraper damage or unsatisfactory scraping effect.

The present invention achieves the above-mentioned purpose through the following technical solutions:

A drill synchronous rotating scraper comprises a cylinder body, a plurality of mounting grooves are opened on the cylinder wall of the cylinder body, a scraper plate is connected to the mounting groove via a first spring, a second spring with an elastic coefficient much larger than that of the first spring is also arranged in the mounting groove, a movable plate is arranged at the top of the second spring, the bottom of the first spring is mounted on the movable plate, one end of the movable plate is connected to a connecting rod, the end of the connecting rod extends to the outside of the cylinder body, the connecting rod has a space for extending outward or contracting inward, and when the connecting rod extends outward, the movable plate moves radially outward along the cylinder body, and when the connecting rod contracts inward, the movable plate is driven to move radially inward along the cylinder body.

A further improvement is that the elastic coefficient of the second spring is 10 to 12 times that of the first spring.

A further improvement is that there are at least three second springs evenly arranged along the bottom of the installation groove, and a plug hole corresponding to each second spring is opened at the bottom of the movable plate.

A further improvement is that a group of opposing guide rails are provided in the installation groove, both ends of the movable plate are movably connected to the guide rails, and a through groove is opened on the guide rail at one end for passing the connecting rod.

A further improvement is that the linkage rod is formed integrally of an axial rod and a radial rod, the axial rod is fixedly connected to the movable plate, and the radial rod extends radially outwardly along the cylinder.

A further improvement is that a spherical groove is provided at the end of the linkage rod, and a rolling ball is movably embedded in the spherical groove.

A further improvement is that the rolling ball is made of silicon nitride material, and the inner surface of the spherical groove is covered with a layer of silicon nitride coating.

A further improvement is that a bolt fixing piece is provided on the side of the scraper plate.

The beneficial effect of the present invention is that when scraping the casing, no matter how the actual inner diameter of the casing changes, the scraper plate can scrape with an almost constant squeezing force, which can avoid the scraper damage and drill bit jamming caused by excessive scraping force, and can also avoid the poor cleaning effect caused by insufficient scraping force.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a schematic diagram of the overall structure of the present invention;

Fig. 2 is a cross-sectional view of a partial structure of the present invention;

FIG3 is a schematic diagram of the connection between the guide rail and the movable plate;

In the figure: 1, cylinder; 2, mounting groove; 3, first spring; 4, scraper plate; 5, second spring; 6, movable plate; 7, connecting rod; 8, socket; 9, guide rail; 10, through groove; 11, spherical groove; 12, rolling ball; 13, bolt fixing part.

Detailed ways

The present application is further described in detail below in conjunction with the accompanying drawings. It is necessary to point out here that the following specific implementation methods are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Technical personnel in this field can make some non-essential improvements and adjustments to the present application based on the above application content.

As shown in Figures 1 to 3, a drill synchronous rotating scraper includes a barrel 1, a plurality of mounting grooves 2 are formed on the barrel wall of the barrel 1, a scraper plate 4 is connected to the mounting groove 2 through a first spring 3, and the scraper plate 4 extends from the side of the barrel 1 to scrape and clean the inner wall of the casing. Bolt fixing members 13 are provided on the side of the scraper plate 4 for installing and removing the scraper plate 4.

The installation groove 2 is also provided with a second spring 5 having an elastic coefficient much greater than that of the first spring 3. Specifically, the elastic coefficient of the second spring 5 is 10 to 12 times that of the second spring 5. When subjected to the same force, the deformation of the first spring 3 is 10 to 12 times that of the second spring 5. There are at least three second springs 5 evenly arranged along the bottom of the installation groove 2, and a socket 8 corresponding to each second spring 5 is opened at the bottom of the movable plate 6. The support of several second springs 5 ensures the stability of the movable plate 6.

A movable plate 6 is provided at the top of the second spring 5, and the bottom of the first spring 3 is mounted on the movable plate 6. A connecting rod 7 is connected to one end of the movable plate 6, and the end of the connecting rod 7 extends out of the cylinder 1. In order to ensure that the movable plate 6 can move smoothly, a set of opposing guide rails 9 are provided in the installation groove 2. Both ends of the movable plate 6 are movably connected to the guide rails 9, and a through groove 10 is opened on the guide rail 9 at one end for passing the connecting rod 7. The width of the through groove 10 is equal to the width of the part through which the connecting rod 7 passes, and the length of the through groove 10 is greater than the thickness of the part through which the connecting rod 7 passes, so that the connecting rod 7 can move back and forth radially.

It should be noted that, under normal circumstances, when scraping, the compression amount of the first spring 3 is 2-3cm, and the compression amount of the second spring 5 acted by the same force is about 2mm. Due to the superimposed structure, this will cause the first spring 3 to also deform by about 2mm. For the first spring 3 with a smaller elastic coefficient, the change in its extrusion force is almost negligible.

The linkage rod 7 is formed integrally of an axial rod and a radial rod, the axial rod passes through the through slot 10 and is fixedly connected to the movable plate 6, and the radial rod extends radially outward along the cylinder 1. A space is provided in the cylinder wall of the cylinder 1 for the linkage rod 7 to extend outward or retract inward, and when the linkage rod 7 extends outward, the movable plate 6 moves radially outward along the cylinder 1, and when the linkage rod 7 retracts inward, the movable plate 6 is driven to move radially inward along the cylinder 1.

A spherical groove 11 is provided at the end of the linkage rod 7. The inner surface of the spherical groove 11 is covered with a layer of silicon nitride coating. A rolling ball 12 is movably embedded in the spherical groove 11. The rolling ball 12 is made of silicon nitride material. The silicon nitride material has a small expansion coefficient, and will not lock in the spherical groove 11 at high temperatures. In addition, the silicon nitride material has extremely high hardness, excellent wear resistance, and lubricity, so that the rolling ball 12 can rotate stably even in a poor environment. The setting of the rolling ball 12 ensures that the linkage rod 7 can move freely against the inner wall of the casing even when the elastic coefficient of the second spring 5 is large, and will not affect the rotation and up and down movement of the scraper.

When the present invention is used, the scraper is installed behind the drill bit and rotates synchronously with the drill bit, and the scraper is sent into the well together. During the sending process, the rolling ball 12 at the end of the linkage rod 7 rolls and contacts with the inner wall of the casing. When a certain section of the sediment on the inner wall of the casing is thick, the thickness of some sediments reaches more than 3 cm, which is equivalent to a reduction of more than 3 cm in the radius of the casing. If it is a traditional scraper, this will obviously greatly increase the extrusion force of the first spring 3, which is easy to cause damage to the scraper and even jamming of the drill bit; while using the present invention, the inner wall of the casing will force the linkage rod 7 to move radially inward, drive the movable plate 6 to move radially inward along the guide rail 9, and the second spring 5 is compressed, so that the distance between the movable plate 6 and the inner wall of the casing remains almost unchanged. At this time, the extrusion force of the first spring 3 is almost unchanged, which is equivalent to scraping with normal extrusion force. Each scraping can make the thicker sediment thinner, and it can be completely cleaned after multiple scrapings. This method of scraping in multiple times can effectively avoid damage to the scraper and jamming of the drill bit. When a certain section of the inner wall of the casing is severely eroded by the drilling fluid, its inner diameter expands. If a traditional scraper is used, this will obviously reduce the squeezing force of the first spring 3 and reduce the scraping effect. However, when using the present invention, the inner diameter of the casing becomes larger, causing the connecting rod 7 to extend outward accordingly, and the movable plate 6 will move radially outward under the elastic action of the second spring 5, while the distance between the movable plate 6 and the inner wall of the casing can still remain almost unchanged, so that the first spring 3 provides sufficient squeezing force to ensure the scraping and cleaning effect.

The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims (6)

1. The utility model provides a drill bit synchronous rotation scraper, includes barrel (1), it has a plurality of mounting groove (2) to open on the section of thick bamboo wall of barrel (1), be connected with scraper plate (4) through first spring (3) in mounting groove (2), its characterized in that: still be equipped with second spring (5) that elasticity coefficient is greater than first spring (3) far in mounting groove (2), second spring (5) top is equipped with fly leaf (6), the bottom of first spring (3) is installed on fly leaf (6), fly leaf (6) one end is connected with trace (7), trace (7) end stretches out to barrel (1) outside, trace (7) have outwards stretch out or inwards shrink the space, and when trace (7) outwards stretch out, fly leaf (6) radially outwards move along barrel (1), when trace (7) inwards shrink, drive fly leaf (6) radially inwards move along barrel (1), the elasticity coefficient of second spring (5) is 10 to 12 times of first spring (3), second spring (5) have at least along the even three that set up of mounting groove (2) tank bottom, and open at the bottom of fly leaf (6) have jack (8) corresponding with every second spring (5).

2. The synchronous rotary drill bit scraper of claim 1, wherein: a group of opposite guide rails (9) are arranged in the mounting groove (2), two ends of the movable plate (6) are movably connected to the guide rails (9), and a through groove (10) is formed in one guide rail (9) at one end of the movable plate and is used for penetrating through the linkage rod (7).

3. The synchronous rotary drill bit scraper of claim 1, wherein: the linkage rod (7) is formed by an axial rod and a radial rod in an integrated mode, the axial rod is fixedly connected with the movable plate (6), and the radial rod extends outwards along the radial direction of the cylinder body (1).

4. The synchronous rotary drill bit scraper of claim 1, wherein: the tail end of the linkage rod (7) is provided with a spherical groove (11), and a rolling ball (12) is movably embedded in the spherical groove (11).

5. The synchronous rotary drill bit scraper of claim 4, wherein: the rolling balls (12) are made of silicon nitride materials, and the inner surfaces of the spherical grooves (11) are covered with a silicon nitride coating.

6. The synchronous rotary drill bit scraper of claim 1, wherein: the side of the scraper plate (4) is provided with a bolt fixing piece (13).