RU2310739C1 - Casing pipe cementing device - Google Patents

Abstract

FIELD: oil production, particularly cementing casings into boreholes.

SUBSTANCE: device comprises stop ring made as pipe closed from below and provided with sealing members, longitudinal slots and radial channels with annular outer ledge made in upper part and conical surface in lower part thereof. Support ring is telescopically installed on outer pipe surface. Support ring is air-tightly connected to casing pipe and provided with pin. Free pin end passes into longitudinal pipe slots and has conical boring mating that of conical pipe surface. Compression spring is installed between outer annular ledge and support ring. Longitudinal slots are blind and are made as upper and lower grooves arranged along pipe perimeter and alternately directed upwards and downwards.

EFFECT: increased operational efficiency.

2 dwg

Description

The invention relates to the oil industry and can be used for cementing casing strings.

The well-known "Valve for casing" (copyright certificate SU No. 1812304, IPC 7 Е21В 34/10, 33/14, publ. In bull. No. 16 from 04/30/1993), containing a valve seat with axial holes, a plate with a conical a working surface located under the saddle, a spring-loaded rod rigidly connected to the plate, and a shear lock, while the valve is equipped with a filter made in the form of a ring and placed in the lower part of the saddle of the axial channel along its inner surface, and the spring-loaded rod is made with a through hole for shear lock, and valve with DLO in the upper part formed with a hole perpendicular to the central axis of the seat and coaxial throughbore spring-loaded rod, wherein the plate is provided with an elastic ring centered conical working surface, the plate may be made of an elastic material.

The disadvantages of this valve are:

firstly, the complexity in the manufacture and maintenance, a large number of parts and, as a result, high cost;

secondly, the low reliability of the closure of the passage channel.

The closest in technical essence is the "Device for cementing the casing string" (patent RU No. 2233966, IPC 7 ЕВВ 33/14, published in bulletin No. 22 of 08/10/2004), including the casing installed in it "stop- ring ”, seals and a dividing plug, while the“ stop ring ”is made in the form of a nozzle muffled from below with annular inner and outer ledges at the top, longitudinal grooves and radial channels located above the muffled portion of the nozzle, and a cylindrical bore is made from the outside ka, in which a technological ring with an external conical surface is rigidly installed, the small base of the cone of which is facing up, and its diameter is equal to the outer diameter of the nozzle, a support ring is telescopically opposite the longitudinal grooves of the latter, the outer side is rigidly connected to the housing and equipped with shear elements, free ends which interact with the longitudinal grooves of the nozzle, on the lower end of the support ring from the side of the inner surface there is a conical bore adequate to the conical technological ring surfaces.

The disadvantages of the design of this device are:

firstly, there is no possibility of forced landing of the conical surface of the pipe on the conical surface of the support ring, which reduces the tightness during operation of the device;

secondly, the impossibility of crimping the casing before cementing without lowering additional crimping equipment (for example, a packer).

An object of the invention is to increase the tightness during operation of the device, as well as the possibility of crimping the casing in the well immediately before cementing it without lowering the additional crimping equipment into the casing.

The stated technical problem is solved by a device for cementing a casing string, including a “stop ring” in the form of a nozzle plugged from below with sealing elements, longitudinal grooves and radial channels with an outer annular ledge at the top and a tapered surface at the bottom, to which a support ring is mounted telescopically to the outside, which is sealed to the casing, equipped with a pin, the free end of which is included in the longitudinal grooves of the pipe, and having a conical bore in the lower end that is adequate to on the surface of the pipe.

What is new is that a compression spring is installed between the outer annular ledge of the nozzle and the support ring, and the longitudinal grooves are non-through in the form of the upper and lower grooves arranged along the circumference of the nozzle and directed alternately up and down, which are connected by a figured groove, allowing for reciprocating moving the pipe relative to the support ring to the free end of the pin is sequentially located in each of the longitudinal grooves, and the upper grooves through one are made elongated upwards.

The figure 1 shows the proposed device in longitudinal section.

The figure 2 shows a scan of the longitudinal grooves.

A device for cementing a casing string consists of a “stop ring” made in the form of a pipe 1 blanked from the bottom with longitudinal grooves 2 and radial channels 3 with an outer annular ledge 4 at the top and a conical surface 5 at the bottom.

A support ring 6 is mounted outside the pipe 1 telescopically on the outside, which is connected hermetically to the casing 7 and provided with a pin 8, the free end of which 9 enters into the longitudinal grooves 2 of the pipe 1. The support ring 6 has a conical bore 10 in the lower end that is adequate to the conical surface 5 of the pipe 1 .

Between the outer annular ledge 4 of the pipe 1 and the support ring 6, a compression spring 11 is installed. The longitudinal grooves 2 (see Fig. 2) are made through and through in the form of a pipe 1 located along the perimeter and directed alternately up and down respectively 12 and 12 'and lower 13 grooves, which are connected by a figured groove 14, which allows for reciprocating movement of the pipe 1 relative to the support ring 6 to the free end 9 of the pin 8 sequentially located in each of the longitudinal grooves 2, and the upper grooves 12 and 12 'are made through one up.

The necessary tightness during operation of the device is provided by sealing elements 15 and 16.

The device operates as follows.

Before the device is lowered into the well (not shown), a pin 8 is installed with its free end 9 in the lower groove 13, while the radial channels 3 of the pipe 1 are blocked by the inner surface of the support ring 6.

Next, the device in the casing string 7 is lowered into the well. After the casing 7 is lowered into the well, it is crimped. To this end, the upper end of the casing 7 is tied at the wellhead with a pump unit and a tank with process fluid (not shown).

Pour technological fluid into the casing 7 and raise the pressure to the intended pressure, while the compression spring 11 is compressed and the pipe 1 moves downward relative to the support ring 6, and the pin 8, which is the free end 9 in the lower groove 13 (see figure 2) longitudinal groove 2, moves through the shaped groove 14 into the upper groove 12 of the longitudinal groove 2. Hold the time and release the pressure in the casing 7 (see figure 1), while the compression spring 11 is opened and the pipe 1 rises up relative to the reference ring 6, the pin 8 moves from the upper groove 12 of the longitudinal groove 2 through a shaped recess 14 in the lower groove 13 of the longitudinal slot 2.

After making sure the tightness of the casing 7 begin to cement it.

For this, the calculated amount of cement is pumped into the casing 7. Next, at the wellhead, a cork plug (not shown) is installed in the casing 7.

By supplying the squeezing liquid to the casing 7, the squeezing cork is forced to be squeezed, which means cement slurry, while the cement slurry acts on the end face of the nozzle 1, which is muffled from below, under the pressure of the squeezing cork pressure, whereby the latter moves downward relative to the support ring 6, and the radial channels 3 of the pipe 1, and the pin 8, which is the free end 9 in the lower groove 13 of the longitudinal groove 2, moves into the elongated upper groove 12 ', while the cement mortar through the radial channels In line 3, pipe 1 is pushed below the device and through holes in a shoe pipe (not shown) of the casing 7 enters the annulus (not shown) of the well through which the cement slurry moves upward.

The cement mortar is pushed into the annulus of the well until there is a sharp increase in pressure on the manometer of the pumping unit pumping the squeezing fluid into the casing 7, which indicates that the squeezing plug rested against the upper end of nozzle 1 with its lower end the grooves are reset, while the pipe 1 due to the return force of the compression spring 11 moves the top relative to the support pipe 6, while the latter with its inner surface is hermetically sealed there are radial channels 3 of the pipe 1, and the pin 8 from the elongated upper groove 12 of the longitudinal groove 2 is lowered and falls into the lower groove 13 of the longitudinal groove 2.

The casing cementing process 7 is completed. Next, the well is left on the OZZ (waiting for the hardening of cement).

The proposed device for cementing the casing string allows to increase the tightness during operation of the device due to the compression spring, which forces the conical surfaces of the nozzle and the support ring to be pressed against each other, and crimping the casing string in the well immediately before cementing it, without lowering additional crimping equipment into the casing string, reduces the total time for well construction, which means saving material and financial costs.

Claims (1)

A device for cementing a casing string, comprising a “stop ring” in the form of a pipe plugged from below with sealing elements, longitudinal grooves and radial channels with an outer annular ledge at the top and a tapered surface at the bottom, to which a support ring is mounted telescopically to the outside, and is sealed to the casing, equipped with a pin, the free end of which is included in the longitudinal grooves of the nozzle, and having in the lower end a conical bore adequate to the conical surface of the nozzle, characterized by m, that a compression spring is installed between the outer annular ledge of the nozzle and the support ring, and the longitudinal grooves are non-through in the form of upper and lower grooves arranged along the circumference of the nozzle and directed alternately up and down, which are connected by a figured groove, which allows reciprocating movement of the nozzle relative to the support ring, the free end of the pin is sequentially located in each of the longitudinal grooves, the upper grooves being extended elongated upward through one.

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