SU1016475A1 - Protector for drill pipes - Google Patents

Abstract

A PROTECTOR FOR BORING PIPES, including a body on which an elastic sleeve with two pairs of diametrically arranged fins, which contact surfaces are made with radii equal to the inner radius of the casing, symmetrically offset from the center of the tread, that are to increase the effectiveness of casing protection by increasing the area of contact between the tread and the column, in one of the pairs of ribs the contact surface is formed by intersecting overheads made with a radius equal to the inner radius of the casing, from centers symmetrically offset from the center of the tread.

Description

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FIG. one

The invention relates to the drilling of oil and gas wells, namely, devices for protecting drill and casing strings from wear.

A drill pipe protector is known, consisting of a housing with an elastic element freely disposed thereon, which has an elliptical shape in cross section. The retaining rings 1 serve to hold the elastic element.

The disadvantages of the tread are the difficulty of making an elastic element in the shape of an ellipse, a significant sectional area. During tripping operations, the protector raises the hydrodynamic pressure, which can lead to absorption or release of the wash solution.

The disadvantage of the tread is the unreliable operation of the elastic element under the action of large pressing forces due to the difference in the shape of the contact surfaces of the casing and the tread.

The closest technical solution to the invention is a protector for drill pipes, comprising a housing on which an elastic sleeve with two pairs of diametrically arranged ribs is mounted for rotation, the contact surfaces of which are made with radii equal to the inner radius of the casing, from centers symmetrically offset from the center tread 2.

A disadvantage of the known tread is the insignificant contact area of the tread and the casing under the action of clamping forces.

With significant clamping forces, the ribs are deformed to such an extent that a cylindrical non-ribbing part of the tread comes into contact with the casing, which leads to a reduction in the gap between the outer surface of the drill lock and the inner surface of the casing, and minor tears or cuts of the thin stretched part of the tread can lead to break.

The aim of the invention is to increase the effectiveness of casing protection by increasing the area of contact between the column and the tread.

This goal is achieved by the fact that in a tread, including a housing, on which an elastic sleeve with two pairs of diametrically arranged ribs, whose contact surfaces are made with radii equal to the inner radius of the casing, are symmetrically offset from the center of the tread, are mounted on rotation of the pairs of ribs, the contact surface is formed by the intersection of surfaces made with a radius equal to the inner radius of the casing, from centers that are symmetrically offset relative It is the center of the tread.

FIG. 1 shows a protector, a longitudinal section; in fig. 2 - the same, cross-sowing.

The drill pipe protector consists of a metal case I, having a cut along the generatrix necessary for putting it on the drill pipe. In the upper and lower parts, the body is threaded for screwing the stop rings 2 and 3, which prevent axial movement of the elastic sleeve 4, fitted with a gap on the body 1 to ensure rotation. A rubber gasket 5 installed between the body is used to hold the tread on the drill pipe. and a drill pipe in a conical gap.

The elastic sleeve 4 contains four fins 6-9, which form two pairs of symmetrically arranged ribs 7, 9 and 6, 8, the contact surfaces of which are formed by radii R equal to the inner radius of the casing and having centers of rotation Oi and O2 offset from the center of the tread O In this case, one pair of edges b, 8 has contact surfaces AB and CD, formed by the intersection of the surfaces (with radius R) forming the edges; the other pair of ribs 7, 9 is a part of the surface of rotation of radius R and has contact surfaces E and F.

The protector works as follows.

When the drill string rotates, the elastic sleeve 4 does not rotate relative to the casing due to the eccentric position of the outer surfaces of the tread relative to the axis of the tread.

As a consequence, the elastic sleeve 4, when the drill string rotates about its own axis and has a constant direction of action of the pressing force applied to the tread, is in a stationary state. Together with the drill string, the body 1 and the parts 2, 3, and 5 fixedly connected to it rotate.

The fixed position of the elastic sleeve 4 prevents wear of the elastic element on the outer surface. The fit of the cylindrical surfaces A, F, B or C, E, D to the casing string reduces their wear during tripping operations.

The eccentric position of the tread contact surfaces increases its stability during rotation of the drill string in the most loaded places, which eliminates the casing and rubbing of the casing string and reduces the tread wear in depth during lifting operations.

Technical and economic efficiency is to increase the reliability of casing and drill string protection from mutual wear.

Claims (1)

PROTECTOR FOR DRILL PIPES, including a housing on which an elastic sleeve with two pairs of diametrically located ribs is mounted with rotation, the contact surfaces of which are made with radii equal to the inner radius of the casing, from centers symmetrically offset relative to the center of the tread, characterized in that, with In order to increase the protection efficiency of the casing string by increasing the contact area of the tread and the string, in one of the pairs of ribs the contact surface is formed by crossing over legs made with a radius equal to the inner radius of the casing, from centers symmetrically offset from the center of the tread. IO16475