RU2335619C2 - Casing pipe valve - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: valve includes stopper with saddle and side channels, and bushing designed to close pressure tight side channels of stopper. The stopper is blinded at the bottom and is connected with the casing pipe. From below the casing pipe is equipped with a lower sleeve in its turn equipped below and inside with a cylinder recess where a hollow tail designed to perform upper axial movement is inserted and fixed in its lower position with shear pins. The sleeve is rigidly installed in the upper end of the hollow tail and is designed to interact in its upper position with the upper surface of the stopper saddle and to close pressure tight the side channels of the stopper from outside. A squeezing plug with a pressure tight head below and a ring recess made on the inside surface at the upper part of the stopper is used for pressure tight closing from the inside the side channels of the stopper. The ring recess of the stopper fixes pressure tight closing head of the squeezing plug in the stopper after interacting between the lower end of the tight pressing head of the squeezing plug and a stopper blind.

EFFECT: upgraded reliability of device operation and reduction of well construction period.

1 dwg

Description

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

Known valve for casing (copyright certificate SU No. 1812304, IPC 7 ЕВВ 34/10, 33/14, published in Bulletin No. 16 of 04/30/1993), containing a valve seat with axial holes, a plate with a conical working surface placed 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 the shear lock and valve seat on the top of the hole arranged 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 a valve for casing strings (patent RU No. 2250355, IPC 7 ЕВВ 34/06, 33/14, published in Bulletin No. 11 of 04/20/2005), including a stop with a seat and side channels, a check valve located below, a sleeve installed in the axial channel of the limiter on the shear elements above the side channels with the possibility of their tight shutoff, while the limiter is additionally equipped with a stopper interacting with the sleeve in its lower position, and the outer surface of the limiter is higher than the side sleep channels the wife with an elastic ring with a stop and made with the possibility of tight installation of the limiter in the required interval between the casing pipes when assembling them, while the saddle is made with cylindrical sampling on the lower plane of the limiter, and the check valve is poppet, spring-loaded with the possibility of rotation relative to the fastener, consisting of an elastic cuff rigidly interconnected, a centralizer and a cylindrical plate on which an annular groove is made, installed opposite to the inside renney lower limiter plane, the outer plane cylindrical plates placed opposite the seat stopper, wherein the elastic sleeve is positioned between the bottom plane and cylindrical restrictor plate.

The disadvantages of this valve design are:

firstly, the complexity of the design, due to the large number of rubber elements and metal rings;

secondly, it is not possible to crimp the casing before cementing it without lowering additional crimping equipment (for example, a packer).

The objective of the invention is to simplify the design of the valve for the casing string, as well as the possibility of crimping the casing string in the well immediately before cementing it without lowering the additional crimping equipment into the casing string.

This problem is solved by the proposed valve for the casing string, including a stop with a seat and side channels, a check valve, a sleeve having the ability to tightly overlap the side channels of the limiter, while the limiter is additionally equipped with a stopper interacting with the sleeve.

What is new is that the limiter is plugged at the bottom and connected to the casing, which is equipped with a lower sleeve from the bottom, equipped with a cylindrical selection from the bottom inside, where a hollow shank is inserted with axial movement upward, fixed in the lower position by shear pins, and the sleeve is rigidly mounted at the upper end hollow shank and has the ability to interact in the upper position with a stopper made in the form of the upper plane of the stopper seat, while the sleeve in the upper position is hermetically sealed overlaps the side channels of the stopper from the outside, while the check valve is placed on top, made in the form of a squeeze plug with a sealing head from the bottom and an annular sample made on the inner surface in the upper part of the stopper, and the annular sample of the stopper fixes the sealing head of the squeeze plug in the stopper after the lower end interacts the sealing head of the squeezing plug with the stopper of the stopper, while the sealing head of the squeezing plug is hermetically sealed from inside the radial channels of the limiter.

The drawing shows the proposed valve for the casing in longitudinal section.

The casing valve includes a bottom stopper 1 with a seat 2 and side channels 3, a sleeve 4, which can tightly overlap the side channels 3 of the stop 1. The stop 1 is additionally equipped with a stop 5 made in the form of the upper plane of the seat 2 of the stop 1.

The limiter is connected to the casing 6, which is equipped from below with a lower sleeve 7, equipped with a cylindrical selection 8 from the bottom from the inside, where the hollow shank 9 is inserted with the possibility of axial movement, fixed in the lower position by shear pins 10.

The sleeve 4 is rigidly installed in the upper end of the hollow shank 9 and has the ability to interact in the upper position with the stop 5. In the upper position, the sleeve 4 hermetically closes the side channels 3 of the limiter 1 from the outside.

In addition, the casing string valve is provided with a check valve placed on top to prevent cement from entering the casing 6 once it has been pushed into the annular space (not shown) of the casing 6.

The check valve is made in the form of a squeeze plug 11 with a sealing head 12 from the bottom and an annular sample 13 made on the inner surface in the upper part of the limiter 1.

The annular sampling 13 of the stopper 1 fixes the sealing head 12 of the squeezing plug 11 in the stopper 1 after the lower end 14 of the sealing head 12 of the sealing head 12 of the squeezing stopper 11 engages the plug 15 of the stopper 1, while the sealing head 12 of the squeezing plug 11 seals the radial channels 3 of the stopper 1 from the inside.

The necessary tightness during operation of the valve is provided by the sealing elements 16.

Valve for casing works as follows.

After preparatory work on the well (not shown), the casing 6 is lowered into it, equipped with a bottom for the proposed casing valve. In the process of lowering the casing string 6 into the well, the liquid in the well flows freely from the bottom upward through the lateral channels 3 of the restrictor 1, filling the inner space of the casing string 6. The lowering of the casing string 6 into the well continues until the lower end of the hollow liner 9 stops against the bottom (not shown ) wells.

Next, the casing 6 is unloaded to the device, while the shear elements 10 are destroyed and the casing 6 together with the limiter 1 rigidly fixed at its lower end and the lower sleeve 7 are lowered down the cylindrical sample 8 of the lower sleeve 7 relative to the hollow liner 9, which is supported on the bottom of the well 9 The process of unloading the casing string 6 to the device continues until the sleeve 4 with its upper end abuts against the stopper 5 of the saddle 2 of the limiter 1, as evidenced by the decrease in the weight of the casing string 6 to zero by indie Ator weight (not shown) mounted on the wellhead, the sleeve 4 is tightly covers the outside of the side channels 3 limiter 1.

The casing 6 is topped up to the wellhead with process fluid and the casing 6 is pressed at the required pressure with the required time delay.

After making sure that the casing 6 is tight, it is lifted up 1-2 meters, while the limiter 1 and the lower sleeve 7, rigidly fixed to the lower end of the casing 6, rise up relative to the remaining motionless hollow shank 9 with the sleeve 4, and the sleeve 4 first comes out from interaction with the stopper 5 of the seat 2, and then the sleeve 4 completely leaves the tight interaction with the seat 2 of the stop 1, while the lateral channels 3 of the stop 1 are fully open and the hollow shank 9 is in the lower part of the cylinder sampling 8 of the lower sleeve 7. With a further rise, the lower end of the hollow shank 9 is lifted from the bottom, providing a hydraulic connection between the inner space of the casing 6 and the annulus of the well.

Casing Valve Ready for Cementing Casing 6.

To do this, pump the required amount of cement into the casing 6. Next, at the wellhead, a casing plug 11 is inserted into the casing 6 with a sealing head 12 with the sealing head 12 down.

By supplying a squeezing fluid to the casing 6, cement slurry is started, while the cement mortar from the casing 6 through the radial channels 3 of the restrictor 1 and the sleeve 4 is forced into the annulus (not shown) of the well through the interior of the hollow liner 9.

The cement mortar is pushed into the annulus of the well until a sharp increase in pressure occurs on the pressure gauge of the pumping unit pumping the squeezing fluid into the casing 6, which indicates that the squeezing plug 11 with the sealing head 12 has passed the annular sample 13 of the limiter 1 and the bottom end 14 rested on the plug 15 of the restrictor 1. The pressure of the squeeze is relieved, while the squeeze plug 11 is sealed by the sealing head 12 in the restrictor 1 in its annular selection 12 and hermetically from within the limiter 1 overlaps its radial channels 3.

Next, the well is left on the OZZ (waiting for cement to harden), while the check valve due to the tight fixation of the sealing head 12 of the squeeze plug 11 in the limiter 1 eliminates the return of cement from the annulus of the well into the casing 6.

The proposed valve for the casing string has a simple design, which increases the reliability of the device, and crimping the casing string in the well immediately before cementing it without lowering the additional pressure testing equipment into the casing allows reducing the total time for well construction, which means saving material and financial costs.

Claims (1)

A casing valve, including a stop with a seat and side channels, a sleeve having the ability to tightly overlap the side channels of the stop, characterized in that the stop is sealed from the bottom and connected to the casing, which is equipped with a bottom lower sleeve, equipped with a cylindrical selection from the bottom to the inside with the possibility of axial upward movement of the hollow shank, fixed in the lower position with shear pins, the sleeve is rigidly installed in the upper end of the hollow shank and is possible the interaction in the upper position with the upper plane of the stopper seat and the tight overlap of the side channels of the stop on the outside, and for tight closing from the inside of the side channels of the stop, a squeeze plug with a sealing head from the bottom and an annular sample made on the inner surface in the upper part of the stop is used, and the ring sample of the stop fixes the sealing head of the squeezing plug in the limiter after the interaction of the lower end of the sealing head end cap with stopper cap.