SU983255A1 - Apparatus for cementing wells - Google Patents

Description

(54) DEVICE FOR CEMENTING WELLS

one

The invention relates to the cementing of wells, namely to devices for cementing casing strings under conditions of absorption of drilling mud.

A device for cementing wells is known, which includes support pipes, naker and tail pipe made of easily drilled material Ts.

A disadvantage of this device is the possibility of breaking the tightness of the borehole elements, which reduces the quality of the cementing of the columns. In addition, in case of sticking of the sub-pakier part of the pipe (shank), more time and money is required to drill the metal-cement bridge.

The closest in technical essence to the invention is a device for cementing wells, including bearing pipes, a container and a hollow cemented plug placed in it with elastic cuffs 2

A disadvantage of the known device is the difficulty of sealing the inner cross section of the shank lowered into the well. To seal it at the wellbore is necessary

Pour the shank head with cement mortar.

The aim of the invention is to enhance the functionality of the device by providing cementing liners under the conditions of absorption of drilling mud.

The goal is achieved by the fact that the device for cementing the sk, important, containing the carrier tubes, the container and the hollow cementing plug with elastic cuffs placed in it, is equipped with a hollow locking plug made with a seating saddle, with an upper end under the cementing plug and with a lower end. under the upper end of the shank, the locking plug being installed in the container on the shearing elements under the cement plug.

FIG. 1 shows the device, general view, transport position; in fig. 2 same working position.

The device for cementing wells includes support pipes 1, container 2, hollow cementing plug 3. Under the cementing plug is installed in the container

the locking plug 4 with the saddle 5. The centered plug is fixed in the container to the shear elements 6, the locking plug is fixed to the shear elements 7, the upper end 8 of the locking plug is filled, for example, in the form of a cone under the cementing plug, and the lower end 9 of the locking plug plugs are also made, for example, in the form of a cone under the upper end 10 of the shank.

The device works as follows. ten

Before starting cementing, a casting element is dropped into the supporting pipes 1, which passes through the hollow cementing plug 3 and sits on the seating seat 5 of the locking plug 4.-15

When the pressure is increased, the elements 7 are cut off, the locking plug is pushed out of the container 2 and sits on the upper end 10 of the shank, isolating its inner section. .

After injection of the calculated amount of the cement-io mortar, the upper cementing plug is dropped, which sits on the hollow cementing plug 3 and closes its channel. With increasing pressure, the elements 6 are cut off and the stopper 3 sits on the locking stopper 4. 25

Owing to the interaction of the mating surfaces of the plugs, the annular space is sealed at the border of the upper end of the shank, which creates conditions for reliably cutting off the hydrostatics of the drilling mud from the hardening cement column. the thief.

Use of a device for cementing a column when absorbing a liquid. allows to provide reliable cement shanks at any depths and does not depend on well design, eliminates damage to the sealing of the string with large pressure drops, eliminating the effect of hydrostatic liquid pressure on the cementing zone during cement hardening.

Claims (2)

1. USSR author's certificate number 186918, cl. E 21 V 33/14, 1962. 2. Volokitenkov A. A. and others. Installation of artificial faces and separation bridges in boreholes. M. Nedra, 1965, p. 21 (prototype). eight phi 2