SU1452940A1 - Dividing cementing plug - Google Patents

Abstract

This invention relates to a technique for drilling oil and gas wells and is intended for cementing casing strings. The goal is to demonstrate the reliability and durability of the cork. It has a housing 1 with an elastic sealing element (E) 2 placed on its side surface, made in the form of a hollow ring filled with liquid 6. On the side surface of the housing 1 there is an annular recess 4 in which E 2 is installed, and in the upper part of the housing 1 - deaf axial outer grooves 5. Under the action of pressure above the plug, it is transmitted through the grooves 5 to O 2, pressing it away from the body and pressing it against the wall of the casing, thereby reducing the friction between E 2 and the side wall and increasing between E 2 and the surface of the pipes. Under the action of pressure pushing the plug down, E2 slides along the side surface of the body and rolls along the inner wall of the pipe, reliably isolating the squeezing fluid from the cement slurry. 1 hp f-ly, 4 ill. with c /)

Description

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The invention relates to the technique of drilling oil and gas wells, and is intended for cementing casing strings, installing cement bridges in a casing string and an open well bore, and injecting cement slurries.

The purpose of the invention is to increase the reliability and durability of the operation of the separation cementing plug.

FIG. 1 shows the proposed cork, longitudinal section; in fig. 2 shows section A-A in FIG. one; in fig. 3 shows a section BB in FIG. one; in fig. 4 shows a section B-B in FIG. one.

Separating cementing plug contains body 1, elastic sealing element 2 and support ring 3. On the side surface of the body there is an annular recess 4 and blind axial outer grooves 5, and the elastic sealing element 2 is made in the form of a hollow ring filled with liquid 6.

The internal cavity of the plug is made identical to the internal cavities of the separation cementing plugs of the type PVTs, PP, SP and PCS or other constructions of the plugs of this type. The elastic sealing element 2 may be made of a rubber hose with a length equal to the circumference of the internal diameter of the column.

Cork works as follows.

After injecting the required volume of cement slurry into the casing into the well, the junction plug is set j (in the case of sectional descent in the upper part of the section). Using the pressure of the slug units, the slug tube moves down the pipe string. The elastic sealing element 2 is pressed against the wall of the pipe and against the body 1 of the tube by the action of its elastic forces. Under pressure, the pressure is transmitted through the hollow axial outer grooves in the housing to the elastic sealing element 2, pressing it away from the housing, and pressing it against the wall of the casing, thereby reducing the friction between the sealing element and the polished side surface of the housing and increasing the friction between the sealing element and the side surface of the casing string. Under the action of pressure, pushing the plug down, the elastic sealing element slides along the polished side surface of the housing and rolls along the inner wall of the casing, thereby reliably isolating the squeezing fluid from the cement slurry.

Claims (2)

1. A separating cementing plug, comprising a housing with an elastic sealing element placed on its side surface, characterized in that in order to increase the reliability and durability of its work, an annular undercut is made on the side surface of the case, and the elastic sealing element is made in the form of a hollow ring filled with liquid and installed in an annular undercut of the case. 2. A plug according to Claim 1, characterized in that in the upper part of the housing there are hollow axial outer grooves. FI.2 Fig.Z