RU127805U1 - SLIDING CENTER - Google Patents

Abstract

A sliding centralizer, comprising a housing with end parts in the form of centering elements and ribs for their connection, rolling elements located in the centering elements, with a uniform pitch, characterized in that the centering elements are made in the form of centering rings (representing bearings), consisting of an inner rings, rolling elements (movable metal balls) and an outer ring in the form of a separator, separating the rolling elements from each other and holding them at an equal distance, while moving metal the balls are made with the possibility of point contact with the walls of the borehole with the possibility of reducing friction forces during the launch of the drill string.

Description

The utility model relates to the oil and gas industry, namely to support-centering devices of the layout of the bottom of the drill string (BHA).

The well-known "Universal mechanical centralizer" (patent RU No. 2256768, E21B 17/10, published on July 20, 2005), comprising a housing, spring-loaded centering elements located in grooves with uniform pitch and forming a calibrating diameter of the device. On the outer surface of the housing, in its upper part, an additional thrust nut for adjusting the calibrating diameter of the device is jointly connected to the housing with a left connecting thread and having openings longitudinal with respect to its axis.

The disadvantages of this device are the design complexity and high requirements for manufacturing accuracy, as well as the large contact area of the centralizer with the walls of the well.

The well-known Centralizer downhole equipment "(patent RU No. 2387791, E21B 17/10, publ. 04/27/2010), containing a hollow rod with a sleeve, conical body, cylinder, piston-pusher and rams, made with the possibility of limited radial extension when moving along the conical body.

The disadvantages of this device are the design complexity and the possibility of jamming dies.

The well-known "Centralizer of the drilling tool" (application for invention No. 94028697, E21B 17/10, publ. 06/10/1996), containing a hollow body and mounted on the body sleeve with centering ribs. A radial blind hole is made in the housing from the outside, and a through radial hole of a smaller diameter, combined with a radial blind hole of the housing, is made between the ribs in the sleeve.

The disadvantage of this centralizer is the rapid wear of the ribs, due to the large contact area of the ribs of the centralizer with the walls of the well.

Close in meaning and design is the "Centralizer-turbulizer ball" (patent RU No. 225198, E21B 17/10, publ. 06/27/2005). It has a housing that is a cylindrical sleeve. Outside the casing, three blades are installed, located symmetrically, through 120 °, relative to the central axis and which are the device supports, providing centering of the drill string. Each blade is made variable in width with an increase to the end part, into which the rolling body is pressed into a rubber ball.

The disadvantage of this centralizer is the rapid wear of the rubber element.

The closest in value is the roller centralizer for casing selected by us as a prototype (developed by Technologiya Ekonomika Resource LLC), equipped with rolling rollers made of red-hot steel, which are located in the supporting ribs of the centralizer (copy is attached).

The disadvantage of such a centralizer is the small number of rollers that will not provide sufficient slippage along the walls of the well, i.e. This centralizer is not applicable when drilling wells.

Thus, the listed well-known centralizers are not universal, do not provide ease of use and ease of installation on the drill string.

The objective of this utility model is to create a new centralizer design devoid of the above disadvantages inherent in analogues and prototype.

This problem is solved by creating a universal sliding centralizer for the drill string, including a housing with end parts in the form of centering rings and ribs that connect these centering rings.

What is new is that the centering rings are made in the form of bearings and consist of an inner ring, rolling elements in the form of movable metal balls and an outer ring in the form of a separator, which separates the movable metal balls at an equal distance from each other.

The proposed utility model is illustrated by drawings (in figure 1 and figure 2), which shows a General view of a moving centralizer and a top view.

The sliding centralizer (figure 1) is a housing with end parts in the form of centering rings of the upper 1 and lower 2, interconnected by ribs 3. The centering rings 1 and 2 are made in the form of bearings and consist of an inner ring 4 (figure 2), rolling elements in the form of movable metal balls 5 and an outer ring 6 in the form of a separator separating the rolling elements from each other, keeping them at an equal distance and directing their movement. On the outer surface of the inner ring 4 there are grooves-raceways (not shown in FIG.), Along which the rolling bodies roll in the form of movable metal balls 5. The movable metal balls 5 are installed so that the contact area with the walls of the well is reduced to a point. The point contact of the movable metal balls 5 with the walls of the borehole reduces the friction force when lowering the drill string.

The ribs 3 are designed to connect the upper 1 and lower 2 centering rings, so it is preferable to make them straight along the entire length. It is advisable to align the centering rings 1 and 2 with the ribs 3 by welding.

It is advisable to have a ratio of height to width in a sliding centralizer of at least 2: 1.

A sliding centralizer works as follows.

On the surface, a sliding centralizer is worn on the drill pipe, secured with retaining rings, it is desirable to install a sliding centralizer on each pipe. The assembled assembly is lowered into the well, where during the drilling process the sliding centralizer together with the drill string will rotate and translate. In this case, the movable metal balls 5 in the centering rings 1 and 2 roll along the walls of the borehole, ensuring reliable centering and stabilization of the drill string in the borehole.

Given that the contact area of the moving metal balls 5 of the sliding centralizer with the walls of the well is reduced to a point, the friction forces during the lowering of the drill string are significantly reduced, thereby simplifying tripping operations.

The implementation of the centralizer of this design allows for good cross-flow in the well, since the sliding centralizer slides in the well due to moving metal balls.

The proposed centralizer has a simple design and can significantly reduce the friction forces on the well walls due to rolling elements, i.e. moving metal balls by reducing the contact of the sliding centralizer with the walls of the well.

The advantage of the sliding centralizer is also its mobility, it is portable, which allows you to fix it anywhere in the drill string.

The sliding centralizer has optimal metal consumption, high work efficiency in wells, since high-quality centering of the drill string eliminates adhesion to the walls of the well and reduces friction when running into the well.

Claims (1)

A sliding centralizer, comprising a housing with end parts in the form of centering elements and ribs for their connection, rolling elements located in the centering elements, with a uniform pitch, characterized in that the centering elements are made in the form of centering rings (representing bearings), consisting of an inner rings, rolling elements (movable metal balls) and an outer ring in the form of a separator, separating the rolling elements from each other and holding them at an equal distance, while moving metal the balls are made with the possibility of point contact with the walls of the borehole with the possibility of reducing friction forces during the launch of the drill string.

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