SU629323A1 - Device for cementing boreholes - Google Patents

Description

one

This invention relates to the cementing of oil and gas wells, in particular, to casing cementing devices.

A device is known, including a sub, a cylindrical packer, a retaining ring, a non-return valve, and a shoe stopper p.J.

The disadvantage of this device is the impossibility of compensating the wear of the packer and the flushing of the drill pipe after cementing.

A device is known for sealing an open borehole when injecting plug mixtures to control absorption during drilling of wells, including a flushing unit, a packer element, an anvil unit and a check valve f2J.

Such a device does not provide for the possibility of flushing the annulus as it descends flushing the drill pipes after the cement mortar has been pressed, and the tightness of the annular space is created only when there is fluid circulation.

The aim of the invention is to improve the reliability and quality of casing cementing.

2

This is achieved by the fact that inside the packer a sleeve is installed with the possibility of axial movement, which is made with radial channels.

Fig. 1 shows a well cementing device, longitudinal section; in fig. 2 - given the section. A-A in FIG. one,

The casing column .1 has a stop stop ring 2 for fitting the packer 3, inside of which is installed a sleeve 4 with radial 4 and channels and a rod 5, the central channel of the device overlaps with the b-7, pressed by the plate 7 with slots to align the pressing force (see Fig. 2). The presence of a ball valve 8 allows the drill pipes to be filled during

O descent and - further ascent. The flushing windows 9 are blocked by a sleeve 10, on which the plug 11 is seated. The device is connected to the drill pipes with the aid of a sub 12,

5 centering the bottom. parts of the device and preventing packer wear when descending above it, a hub 13 is installed, having 14 dch sealing in juice — in the event of a packer failure.

The sleeve 10 is attached to the sub 2 with shear pins 15. The total diameter of the sleeve 4 is smaller than the diameter of the opening of the stop ring 2 and the acre. 3

The device works as follows.

When moving inside the column, the packer 3 seals the annular space and forces the flushing fluid out of it into the annulus. The displaced air flow fluid partially through a special wellhead device is discharged into the annulus, and from there through the valve 8 fills the internal cavity of the drill pipe. When the packer 3 reaches the stop ring 2, it rests against its seating surface and, as the drill pipes are partially loaded, the sleeve 4 enters the hole, the rings, and the packer 3 is compressed in the space formed between the casing, the centralizer 13, the sleeve 4 and the ring 2.

Sealing by the packer occurs, not only under the action of the partial weight of the drill string, but also under the action of pumped fluids entering the space between the packers n and the bushing through the radial holes in it.

When pumping cement mortar (after the packer is seated) due to the pressure rising above the sharsm, the latter is pushed through the plate 7 and retained in the sleeve 4 by the rod 5.

After injection of the entire volume of the cement slurry following it, the separation plug 11 sits on the sleeve 10 and is wedged there, which results in noBfcffiffiHreo pressure above it, cutting the pin 15, moving

the sleeve 10 and, as a consequence, the opening of the windows and the process of flushing the drill pipe with the release of flushing fluid through the annular space.

The circulating fluid of the drilling fluid in the annular space occurs under the action of the weight of the drill pipe, so the casing in its upper part should not be completely filled. The height of the empty part should be determined in accordance with the valid instructions for the casing descent.

The use of this device will allow to reduce the number of cementing equipment, participating in the process of casing cementing, and to reduce the costs of drilling cement glasses in it.

Claims (1)

Invention Formula A well cementing device comprising a drill pipe assembly, a valve, a packer and a ring mounted inside the casing CTOTI, a check valve and a guide plug, characterized in that, to ensure the reliability and quality of casing cementing, a sleeve is installed inside the packer the possibility of axial movement, which is made with radial channels. Sources of information taken into account in the examination: 1, Kuliev SM. Drilling of oil and gas wells. M., Nedra, 1958, p. 299. 2j Krylov V.I. Complications with well drilling. M., Nedra, 1965, p. 190.