RU2298640C1 - Casing pipe valve - Google Patents

Abstract

FIELD: oil production industry, particularly means for casing pipe centering.

SUBSTANCE: valve comprises limiter with seat and axial side channels, hollow bush and spring-loaded disc slide. Spring-loaded disc slide may cooperate with seat in air-tight manner. Hollow bush is installed in axial channel of the limiter through shear members and is arranged over the side channels to provide side channel sealing. Limiter has through channels located between axial channel and seat. Axial channel is closed with cap from below. Disc slide may move in axial direction without side limiter channels closing.

EFFECT: simplified structure and increased operational reliability of casing pipe valve, possibility of cement grout injection without casing pipe throat loss.

1 dwg

Description

The invention relates to the oil industry, in particular to cementing casing strings.

The well-known "Casing Valve" (see patent SU No. 1493768, IPC 7 ЕВВ 34/10, publ. BI No. 26 23.10.84), comprising a housing with central and peripheral axial channels, a saddle mounted underneath in the lower part of the central channel of the housing a body made in the form of a float and located in the lower part of the sleeve movably mounted in the central channel of the body of the sleeve with radial channels and a bursting disc under them, while it is equipped with an additional locking body with a drive unit in its working position, the peripheral channel is made with two dlamas, and the cavity between them is connected with the cavity of the central channel by a radial channel, and the drive unit of the additional locking element is made in the form of a wedge element and is installed in the initial position with the possibility of interaction with the movable sleeve.

Also known is a “Casing Valve” (see patent SU No. 1120093, IPC 7 ЕВВ 34/10, publ. BI No. 39 23.10.84), comprising a housing with central and peripheral axial channels, movably mounted with axial movement in the central a housing channel a sleeve with a crimping diaphragm and radial channels in the upper part and a locking element, while it is equipped with an additional sleeve mounted coaxially with a movable sleeve on shear elements in the central channel of the housing above its peripheral channels, and the locking element is made nen in the form of a float and is rigidly connected with the lower part of the movable sleeve, the latter having additional radial channels that are compatible with the peripheral channels of the housing at its upper position.

The disadvantages of both designs are:

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

secondly, it is impossible to work using squeeze plugs;

thirdly, during the lifting of the locking member before it is seated in the saddle, which is neither standardized nor regulated, the spaces under the valve and above the valve communicate through the central and lower radial channels, as a result, the cement slurry enters the casing from the annulus.

The closest in technical essence and the achieved result to the proposed one is "Valve for casing" (see patent RU No. 2250355, IPC 7 ЕВВ 34/06, 33/14, publ. BI No. 11 of 04/20/2005), including a limiter with a seat and side channels, a check valve placed below, a sleeve installed in the axial channel of the limiter on shear elements above the side channels with the possibility of their tight overlap, and the limiter is additionally equipped with a stopper interacting with the sleeve in its lower position, while the outer turn The limiter above the lateral channels is equipped with an elastic ring with a stop and is configured to tightly install the limiter in the required interval between the casing pipes when assembling them, the seat being made with cylindrical sampling on the lower plane of the limiter, and the check valve is made poppet, spring-loaded with the possibility of rotation relative to fastenings to the limiter, consisting of a rigidly connected elastic cuff, a centralizer and a cylindrical plate, on which a ring is made a groove installed opposite the inner lower plane of the limiter, while the outer plane of the cylindrical plate is located opposite the saddle of the limiter, and the elastic cuff is located between the lower plane of the limiter and the cylindrical plate, while the limiter is located in the lower part of the housing and is provided with through holes, the check valve seat made in the form of an inner annular protrusion of the housing, while on the saddle, below on the outer surface of the axial channel of the limiter, with awn axial displacement of the poppet valve sealingly mounted, spring-loaded relative to the bottom stop.

The disadvantages of this design are:

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

secondly, the limiter and the hollow sleeve significantly reduce the internal passage section of the casing, which increases the time and effort of the injection of cement;

thirdly, with significant cement injection pressures, the elastic cuff can be destroyed, which leads to failure of the poppet valve and a decrease in the reliability of the valve for the casing as a whole.

An object of the invention is to simplify the design and increase the reliability of the valve for the casing, allowing without loss of the internal bore of the casing to inject cement.

The technical problem is achieved by the described valve for the casing string, including a stopper with a seat and with axial and side channels, a hollow sleeve mounted in the axial channel of the stopper on the shear elements above the side channels with the possibility of their tight overlap, a spring-loaded poppet check valve made with the possibility of tight interaction with a saddle.

What is new is that the limiter is provided with through channels located between the axial channel and the seat, and its axial channel is equipped with a plug from below, and the poppet valve is capable of axial movement without blocking the side channels of the limiter, with respect to which it is spring-loaded upward.

In the drawing, a valve for a casing string is shown in longitudinal section.

The casing valve consists of a restrictor 1 with a seat 2 and an axial 3 and side channels 4, a hollow sleeve 5 installed in the axial channel 3 of the limiter 2 on the shear elements 6 above the side channels 4 with the possibility of their tight overlap, poppet check valve 7.

The limiter 1 is provided with through channels 8, and its axial channel 3 is sealed from below by means of a plug 9. A poppet check valve 7 is hermetically mounted on the outer surface of the axial channel 3 of the limiter 1 with the possibility of axial movement. The poppet check valve 7 is hermetically placed on the bottom of the saddle 2 of the stop 1 and from the bottom is pressed by the spring 10 relative to the axial channel 3 of the stop 1 muffled by the plug 9.

Unauthorized fluid flows are prevented by sealing elements 11, 12, 13.

The valve for the casing string operates as follows.

The casing assembly valve (see drawing) is hermetically installed between the casing pipes (not shown), after which the casing is lowered into the well. During the descent, the borehole fluid fills the inner space of the casing, flowing from bottom to top through the side channels 4 and the axial channel 3 of the restrictor 1, so that no fluid is added and the effect of “pistoning” is excluded (pulsed outflow of fluid at the mouth during descent due to water hammer) .

Upon reaching the required interval, cement is injected into the casing annulus (not shown) using a cement plug (not shown).

Under the injection pressure of the cement slurry acting on the poppet check valve 7 from above through the through holes 8 of the stop 1, the poppet check valve 7 moves down the outer surface of the axial channel 3 of the stop 1, compressing the spring 10. As a result, the cement slurry rushes through the open poppet check valve 7 under the valve, and then in the annulus of the casing.

Upon completion of the injection, the cementing plug from above acts on the hollow sleeve 5, which is installed in the transport position by means of shear elements 6, in the axial channel 3 of the stopper 1 muffled from below by the plug 9 above the side channels 4. As a result, the shear elements 6 are destroyed, and the hollow sleeve 5 is shifted down to until with its lower end it abuts against the axial channel 3 of the limiter 1 muffled from below by the plug 9, eliminating the effect of “pistoning”.

As a result, the hollow sleeve 5 hermetically seals the side channels 4 of the limiter 1, after which they catch a “stop” (a significant increase in pressure at the mouth), and then release the pressure inside the casing, while the poppet check valve 7 moves upward due to the return force of the compressed spring 10 relative to the axial channel 3 of the limiter 1 and seals hermetically on the saddle 2 of the limiter 1, blocking the flow area and preventing the cement from flowing back into the casing.

The proposed valve for the casing string is a simple and reliable design with a small number of parts, in addition, it does not narrow the internal bore of the casing string, which results in savings in material and financial costs.

Claims (1)

A casing valve, including a limiter with a seat and with axial and side channels, a hollow sleeve installed in the axial channel of the limiter on shear elements above the side channels with the possibility of their tight closing, a spring-loaded poppet check valve made with the possibility of tight interaction with the seat, characterized in that the limiter is equipped with through channels located between the axial channel and the seat, and its axial channel is equipped with a plug from below, and the poppet valve is made with possible awn axial movement without overlapping the lateral limiter channels, against which is biased upwardly.