RU2783578C1 - Membrane crimping valve, borehole layout and method for valve operation - Google Patents

Abstract

FIELD: valve devices.

SUBSTANCE: invention relates to valve devices used for crimping of tubing and organization of communication of an annular space and an inner cavity of tubing. A membrane crimping valve contains upper and lower adapters connected by means of thread, a floating plug installed in an inner space of the lower adapter with the possibility of axial movement. The floating plug contains a lower case element, in which two cutting rings and destructible membrane between them are installed, and an upper case element connected by means of thread to the lower case element and fixing cutting rings with destructible membrane installed between them in the lower case element. A side part of an outer surface of the lower case element of the floating plug is made with grooves, and a lower part of the outer surface of the lower case element of the floating plug is a spherical cone. The invention also relates to borehole layout containing such a valve and a method for its operation.

EFFECT: invention is aimed at an increase in the reliability and efficiency of technological operations in a well, requiring crimping of a tubing string.

8 cl, 5 dwg

Description

FIELD OF TECHNOLOGY TO WHICH THE INVENTION RELATES

The invention relates to valve devices used for pressure testing tubing (tubing) and organizing the communication of the annulus and the internal cavity of tubing tubing, and can be used for technological operations carried out in wells. The invention also relates to a downhole assembly containing such a valve and a method of operating it.

BACKGROUND OF THE INVENTION

When carrying out various technological operations in a well, one of the mandatory steps is pressure testing of the tubing string. Pressure testing valves are traditionally used, in the design of which a ball-seat sealing element (valve pair) is used. Accordingly, it becomes necessary to use backwash or special fishing equipment to lift the ball (shut-off device) from the seat completely out of the well and/or to a predetermined height above the seat to ensure fluid flow. In any case, additional time is required to carry out this operation, which leads to additional time, technological and economic costs during repair or maintenance work.

In the prior art, a device for crimping drill pipes in a well is known (USSR St. No. 1051 235; IPC E21B 34/06; publ. 10/30/1983), which consists of a housing with upper and lower stops, a floating circulation sleeve with axial central and peripheral channels equipped with direct-acting valves with a shut-off body. After reaching the bottom, direct circulation is restored and the pressure is increased by pressure testing of the pipe string. When the circulation is restored, the shut-off valve closes the passage of the channels, and the bushing moves down to the bottom stop, the pressure inside the string gradually increases, and after exceeding the drilling pipe pressure value, the membrane breaks and the possibility of direct circulation of the flushing agent is achieved.

Accordingly, the known device makes it possible to partially solve the above-mentioned problem of using a ball-seat valve pair. However, the known device has a rather complex design and has a number of disadvantages, in particular, the presence of valves in the peripheral channels reduces the reliability of the device as a whole, because. in case of violation in one of them (or in all), the device will not work properly, which will lead to the need to raise the tubing string, replace the shut-off element or the entire valve, and re-run the device for pressure testing.

Also known in the prior art is a device for crimping drill pipes in a well (Ed. St. USSR No. 973796; IPC E21B 34/06; publ. 11/15/1982), closest in technical essence to the proposed invention. The known device comprises a housing, in the bore of which a sleeve with peripheral holes and an axial channel covered by a membrane is freely installed. The membrane is secured with a threaded washer. The pressure required for pressure testing is created in the drill string. After pressure testing is completed and the tightness of the drill string is established, excess pressure is created in the pipes, sufficient to rupture the membrane. Thus, after the rupture of the membrane, it is possible to flush the well and drill.

The disadvantage of this device is the narrow flow area of the main axial channel due to the presence of peripheral holes, as well as the risk of a loose fit of the sleeve to the valve seat as a result of accumulated dirt when the device is lowered into the well, which reduces the reliability of the device as a whole, and can lead to that the device will not work properly, resulting in the need to lift the tubing string, replace the valve device, and re-run the device for pressure testing.

DISCLOSURE OF THE INVENTION

The present invention is aimed at eliminating the above problems of the prior art and solves the problem of improving the reliability and efficiency of technological operations in the well, requiring pressure testing of the tubing string.

In one aspect of the invention, a pressure testing diaphragm valve is provided, comprising:

top sub and bottom sub connected by thread,

a floating plug installed in the internal space of the lower sub with the possibility of axial movement,

at the same time, the floating plug contains a lower body element in which two shear rings are installed and a destructible membrane between them, and an upper body element connected by means of a thread to the lower body element and fixing the shear rings with a destructible membrane installed between them in the lower body element,

wherein the side part of the outer surface of the lower body element of the floating plug is made with grooves, and the lower part of the outer surface of the lower body element of the floating plug is a spherical cone.

In one of the options, a valve is proposed, in which the ruptured membrane is made of a material soluble in an acid environment.

In one embodiment, a valve is provided in which the shear rings are sharp-edged.

In one embodiment, a valve is proposed, in which the grooves on the side of the outer surface of the lower body element of the floating plug are made axially along the floating plug.

In one embodiment, a valve is proposed, in which the grooves on the side of the outer surface of the lower body element of the floating plug are made spirally along the floating plug.

In one embodiment, a valve is provided that provides an O-ring between the top and bottom subs.

In one embodiment, a valve is provided that includes locking screws to prevent the top and bottom subs from unwinding.

In one additional aspect, a downhole assembly is provided comprising a tubing string (tubing string) with a valve in accordance with the first aspect of the invention.

In one further aspect, a method is provided for operating a valve as described above during downhole operations, comprising the steps of:

install the valve on the tubing string;

run the tubing string with the valve installed to the required depth;

injecting liquid into the inner cavity of the tubing string until a predetermined pressure test pressure is reached, which is lower than the burst pressure of the valve membrane being destroyed;

withstand the specified time of crimping;

when a positive pressure test result is achieved, the pressure in the tubing string is increased to the rupture pressure of the destructible membrane;

after opening the through hole, technological operations are carried out in the well.

Thanks to the present invention, in all its aspects and embodiments, the technical result is provided, which consists in increasing the efficiency of technological operations during the maintenance and overhaul of oil and gas wells. In particular, due to the fact that the side part of the outer surface of the lower body element of the floating plug is made with grooves, and the lower part of the outer surface of the lower body element of the floating plug is a spherical cone, the well fluid is ensured when the tubing string is lowered for self-filling, and tight fit of the floating plug to the saddle during subsequent pressure testing of the tubing string.

These and other advantages will be detailed in the following description, which also shows and describes embodiments of the present invention in more detail. It should be understood that the drawings and description are, by nature, to be considered illustrative and not restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

The proposed invention is illustrated in the drawings, where:

in fig. 1 shows the proposed valve in cross section,

in fig. 2-5 schematically show the operation of the proposed valve during technological operations in the well.

The figures are drawn to approximate scale, some elements may be shown larger for clarity, some elements may be shown smaller for simplification. It should be understood that the embodiments illustrated in the figures are not intended to limit the scope of the appended claims.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The invention relates to valve devices used for pressure testing tubing (tubing) and organizing the communication of the annulus and the internal cavity of tubing tubing, and can be used for technological operations carried out in wells. The invention also relates to a downhole assembly containing such a valve and a method of operating it.

The proposed invention is illustrated in the drawings, where in Fig. 1 shows the proposed valve in cross section, FIG. 2-5 schematically show the operation of the proposed valve during technological operations in the well. In FIG. 2-5 arrows show the direction of fluid flow.

Further, continuing generally with FIG. 1-5, in one of the aspects of the invention, a pressure testing diaphragm valve is proposed, containing a top sub 1 and a bottom sub 2, connected by means of a thread, a floating plug 3 installed in the internal space of the bottom sub 2 with the possibility of axial movement, while the floating plug 3 contains a bottom housing element 32, in which two shearing rings 5 and a destructible membrane 4 are installed between them, and an upper body element 31 connected by means of a thread to the lower body element 32 and fixing the shear rings 5 with a destructible membrane 4 installed between them in the lower body element 32, while the side part 34 of the outer surface of the lower body element 32 of the floating plug 3 is made with grooves, and the lower part 33 of the outer surface of the lower body element 32 of the floating plug 3 is a spherical cone. In the preferred embodiment, the upper body element 31 is made in the form of a nut with grooves on the outer surface, allowing the flow of well fluid during the descent of the tubing string with the valve installed and its self-filling, as will be described in more detail below.

This ensures unimpeded passage of the well fluid during the descent of the tubing string with a valve installed for its self-filling, as well as a tight fit of the floating plug to the seat during subsequent pressure testing of the tubing string, as will be described in more detail below. Thus, the technical result is provided, which consists in increasing the efficiency of technological operations during the maintenance and overhaul of oil and gas wells, by reducing the time and technological costs for filling the tubing string with fluid for pressure testing, and in addition, reducing the risk of fluid leakage due to loose fit of the floating plug to the seat during crimping.

In one of the variants, a valve is proposed, in which the destructible membrane 4 is made of a material soluble in an acid medium. The valve elements, including the body elements of the floating plug, are made of steel that is not affected by the acidic environment of the well. Together with the insignificant thickness and weight of the membrane, this ensures complete dissolution of the membrane fragments after its destruction, thereby not clogging the bottomhole zone of the well.

In one embodiment, a valve is proposed in which the shear rings 5 are made with sharp edges. Due to this design, the destruction of the membrane occurs at a lower value of the applied pressure, contributing to the greater efficiency of the proposed valve during technological operations.

In one embodiment, a valve is proposed in which the grooves on the side portion 34 of the outer surface of the lower body element 32 of the floating plug 3 are made to extend axially along the floating plug. This ensures uniform flow of the well fluid during the descent of the tubing string, on which the proposed valve is installed, for self-filling of the tubing string, contributing to the greater efficiency of the proposed valve during technological operations.

In one of the options, a valve is proposed, in which a sealing ring 7 is provided between the upper and lower subs 1, 2, which ensures reliable sealing of the connection of the upper and lower subs. In addition, in one of the variants, a valve is proposed, in which fixing screws 8 are provided to prevent the top and bottom subs 1, 2 from unwinding, which also ensures a reliable connection of the top and bottom subs, increasing the reliability of the valve as a whole.

The following describes the use of the valve in downhole operations. Initially, it is necessary to assemble the valve, for this, the destructible membrane 4 is installed between the shearing rings 5, which are located in the lower housing element 32. The upper housing element 31 is inserted into the lower housing element 32 and connected by means of a thread made on the inner surface of the lower housing element 32 and on the outer surface of the upper housing element 31. The upper housing element 31 is screwed into the lower housing element 32 until the cutting rings stop against the corresponding protrusions of the lower housing element (not indicated in the figures). This ensures reliable fixation of the shear rings 5 with a destructible membrane 4 between them in the lower housing element 32.

The floating plug 3 assembled as described above is placed in the inner space of the lower sub 2, and the upper sub 1 is inserted from above and connected by means of a thread made on the inner surface of the lower sub 2 and on the outer surface of the upper sub 1. The upper sub 1 is screwed into the lower sub 2 to the stop of the shoulders (not indicated) of the top sub 1 against the end surface of the bottom sub 2. In this case, the distance between the end surface of the top sub 1 and the seat 21, made in the form of a cone in the bottom sub 2, provides the possibility of axial movement of the floating plug 3 in the internal space of the valve . Thus, the course of the floating plug is limited by the top sub 1.

For a more reliable hermetic connection of the top and bottom subs 1, 2, a sealing ring 7 is installed in the connection area. In addition, to prevent the top and bottom subs 1, 2 from unwinding, they can be fixed with additional fixing screws 8.

The valve assembled in the manner described above is installed on the tubing string. For ease of installation, the valve can be manufactured in several standard versions according to the type of connecting thread of the tubing.

Returning to the method of operation of the proposed valve, the descent of the tubing string with the valve installed to a predetermined depth is started. In this case, the floating plug 3 is axially displaced upwards, and the liquid contained in the well passes through the lower opening of the valve, and then along the grooves provided in the side part 34 of the outer surface of the lower body element 32 of the floating plug 3, enters the inner space of the tubing string.

After the valve is installed at the required depth in the tubing string, liquid is injected into the internal cavity of the pipe string until the required pressure is reached, which is lower than the burst pressure of the destructible membrane (Fig. 2). The floating sleeve 3 descends into the seat 21 and fits securely to it due to the shape of the lower part 33 of the outer surface of the lower body 32, sealing the valve and preventing further flow of well fluid from the annulus into the tubing string.

Then, pressure testing of the tubing string or equipment is carried out with a predetermined time delay (Fig. 2). When a positive pressure test result is achieved, the pressure is increased to the membrane burst pressure (Fig. 3) to completely open the through hole and organize communication between the annulus and the internal cavity of the tubing string.

The diaphragm burst pressure depends on the design of the valve, namely the thickness and material of the diaphragm. Thus, when assembling the valve, a diaphragm is selected that corresponds to the required pressurization pressure, i.e. holding it without destruction.

After the opening of the through hole is complete, the necessary technological operations are carried out in accordance with the technological work plan or other regulatory and technical document, for example, work on the current and major repairs of wells (Fig. 4-5), including: direct flushing of the well; well backwashing; well acid treatment; exploration of a well with the help of geophysical instruments, etc.

Thus, in one additional aspect, a downhole assembly is provided comprising a tubing string (tubing string) with a valve in accordance with the first aspect of the invention.

In one further aspect, a method is provided for operating a valve as described above during downhole operations, comprising the steps of:

install the valve on the tubing string;

run the tubing string with the valve installed to the required depth;

injecting liquid into the inner cavity of the tubing string until a predetermined pressure test pressure is reached, which is lower than the burst pressure of the valve membrane being destroyed;

withstand the specified time of crimping;

when a positive pressure test result is achieved, the pressure in the tubing string is increased to the rupture pressure of the destructible membrane;

after opening the through hole, technological operations are carried out in the well.

Thanks to the present invention, in all its aspects and embodiments, the technical result is provided, which consists in increasing the efficiency of technological operations, for example, during the maintenance and overhaul of oil and gas wells. In particular, as described above, due to the fact that the side part of the outer surface of the lower body element of the floating plug is made with grooves, and the lower part of the outer surface of the lower body element of the floating plug is a spherical cone, unhindered passage of the well fluid is ensured when the tubing string is lowered for its self-filling, as well as a tight fit of the floating plug to the saddle during subsequent pressure testing of the tubing string.

In addition, the proposed invention, as explained in detail above, is characterized by a number of additional positive effects:

- Increased bore diameter of the plug contributes to the unimpeded passage of geophysical instruments, while the diameter of the valve bore depends on the size and type of the connecting thread.

- Due to the fact that it is made of an alloy that is soluble in the acidic environment of the well, and due to its low weight, the membrane fragments completely dissolve after destruction, without clogging the bottomhole zone.

- Reduction of time costs for carrying out technological operations after crimping.

- The sealing surface of the valve has the shape of a circle on a gentle cone, which prevents the valve from leaking due to the accumulation of solid particles on the contact surface of the cone.

- Installing a plug in the valve during assembly eliminates the risk of damage to the plug that occurs if it is dropped from the wellhead.

- Fluid grooves of increased flow area on the outer surface of the plug minimize the risk of clogging of the valve during descent and operation.

- Possibility of auditing the valve in the conditions of the workshop of the team for the current and major workover of wells.

In the above description of the examples, directional terms (such as "above", "top", "below", "bottom", "top", "bottom", etc.) are used for the convenience of referring to the accompanying drawings. In general, "above", "up", "up" and similar terms are associated with the direction to the earth's surface relative to the well, and "below", "lower", "down" and similar terms are associated with the direction away from the earth's surface relative to the well.

Claims (18)

1. Diaphragm pressure test valve, containing: top sub and bottom sub connected by thread, a floating plug installed in the internal space of the lower sub with the possibility of axial movement, at the same time, the floating plug contains a lower body element in which two shear rings and a destructible membrane are installed between them, and an upper body element connected by means of a thread to the lower body element and fixing the shear rings with a destructible membrane installed between them in the lower body element, wherein the side part of the outer surface of the lower body element of the floating plug is made with grooves, and the lower part of the outer surface of the lower body element of the floating plug is a spherical cone. 2. The valve according to claim 1, in which the breakable membrane is made of a material soluble in an acidic environment. 3. The valve according to claim. 1, in which the cutting rings are made with sharp edges. 4. The valve according to claim. 1, in which the grooves on the side of the outer surface of the lower body element of the floating plug are made passing axially along the floating plug. 5. The valve according to claim 1, in which an o-ring is provided between the top and bottom subs. 6. The valve of claim 1, which includes locking screws to prevent the top and bottom subs from unwinding. 7. Downhole assembly containing a tubing string (tubing string) with a valve installed on it according to claim 1. 8. The method of operating the valve according to claim 1 during technological operations in the well, which includes the steps at which: install the valve on the tubing string; run the tubing string with the valve installed to the required depth; injecting liquid into the inner cavity of the tubing string until a predetermined pressure test pressure is reached, which is lower than the burst pressure of the valve membrane being destroyed; withstand the specified time of crimping; when a positive pressure test result is achieved, the pressure in the tubing string is increased to the rupture pressure of the destructible membrane; after opening the through hole, technological operations are carried out in the well.

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