RU2686562C1 - Sealing element to hydraulic inflatable packer and method of its manufacturing - Google Patents

Abstract

FIELD: seals.SUBSTANCE: group of inventions relates to a sealing element for a hydraulic inflatable packer and a method for production thereof. Sealing element to hydraulic inflatable packer includes inflatable part made in the form of hollow cylinder, with connecting metal end fittings consisting of nipple and coupling, coupling is fitted on the outside, and nipple is installed inside. Inflatable part comprises inner sealing layer of oil and abrasion-resistant rubber, at least one paired power layer of intercrossed winding at angle of 24–26 degrees to axis of steel brass spring wires. Intermediate rubber layers are applied between layers of wire. On the wire layers at angle of 24–26 degrees, one paired layer of cord nylon fabric is applied, on which outer protective sealing rubber layer is applied. Coupling is made from structural alloyed steel with subsequent thermal treatment by hardening method. On inner surface of coupling and external surface of nipple there are annular grooves and protrusions, which form a connection of "tenon-groove" type during assembly. Proposed method comprises assembling end fixtures on prefabricated inflatable workpiece, specifically coupling on nipple with inflatable part arranged there between. Prior to fitting the coupling and the nipple, mandrel is fitted on one end of the inflatable part, the shank of which is brought out through the central opening of the nipple, and the tip having an outer diameter greater than the inner diameter of the nipple is located in front of the nipple. Drawing of mandrel is performed by means of translational movements of machine.EFFECT: technical result is higher reliability of structure.2 cl, 4 dwg

Description

The present invention relates to a device for hermetic overlap, designed to provide temporary blocking of a well, in particular an oil well or pipeline. The proposed sealing element is one of the parts of the hydraulic inflatable packer of modular design.

Inflatable packers are used in the petroleum industry to seal the annular space and sever the two zones of the wellbore during repair and insulation works, acid treatment of formations and other technological operations carried out under conditions of high pressure drop.

A characteristic feature of inflatable packers is that to press the sealing element to the casing or horizontal wellbore, the pressure of the fluid supplied into the packer's internal cavity is used, and the inflatable part of the packer expands under the influence of the internal pressure.

In the patent RU 2441973 (publ. 10.02.2012, Bull. No. 4) described improved inflatable packers. A plate for use in an inflatable packer contains a body element having a length, width and thickness and containing at least one groove made therein, and at least one protrusion extending therefrom, adapted to interact with the body elements of adjacent plates of an inflatable packer, and a plurality of reinforcing elements arranged in a body element and formed in a braided structure or a twisted structure, wherein the inflatable packer contains an elastic balloon and a plurality of plates arranged along an elastic Nogo cylinder and having a plate reinforcing elements at least partially open to facilitate the fixing of the inflatable packer relative to the surrounding wellbore wall.

A device is hermetic overlap used to block a well or pipeline (patent for invention RU 2389864, publ .: 20.05.2010, Bull. No. 14), which contains an expanding element and end organs. The expanding body is made of a multilayer, containing at least one ring and fiber structure of high density, formed by a multitude of thin and long fibers with high mechanical strength with a diameter from 5 microns to 100 microns. The fibers interconnect the end organs and are wound in a spiral fashion. The winding angle of the fibers with respect to the longitudinal axis of symmetry is from 45 ° to 60 ° at the end sections and from 15 ° to 30 ° in the central part of this coupling.

In the patent RU 2355937 (publ .: 20.05.2009, Bull. No. 14) the one-piece high-pressure valve end fittings is disclosed, which contains a rubber-reinforced sleeve with the outer and inner layers removed at the end, a nipple with outer annular projections made in the area of the frame force seal sleeves. The first annular protrusion on the side of the junction assembly is made with a truncated apex, and the coupling with internal annular protrusions of different heights with the formation, during compression, of the zone of the force seal of the sleeve frame. There are sealing zones and areas of reduced compression of the sleeve. In addition, the truncated part of the top of the first from the side of the connection node of the outer annular protrusion of the nipple is tapered, and on the outside of the coupling there is a triangular annular groove that coincides in the same plane in the area of the power seal of the sleeve frame with the inner circumferential protrusion of the coupling the first from the connection node, the outer annular protrusion of the nipple is closer than to the second outer annular protrusion of the nipple, by the amount of elongation of the coupling when it is crimped.

A known method of assembling a one-piece connection of high-pressure hoses (patent for invention RU 2153124, published: 07/20/2000 Byul. No. 20), which includes putting the crimp sleeve onto the free end of the sleeve, facing inwards and made from one side of the coupling, introducing the sleeve opening from the coupling nipple side with the locking and sealing grooves and the installation of the sleeve into the crimping device with subsequent mutual bonding between the sleeve, the coupling and the nipple; the coupling has a transitional conical outer surface located from the end of the coupling on the side of the flange to its cylindrical surface, and on the inner surface of the coupling there is a section with annular ribs, before fastening it into the hole of the nipple in the hole the end of the nipple and crimp the coupling device Cams in the radial direction successively, first a cylindrical surface, bringing its diameter to the outer diameter of the flange, while the annular ribs cut through the A rubber layer of rubber sleeves and cut into the power braid and deform it, and partially deform themselves, and then squeeze the flange, introducing it into the locking groove, and deform it there, forming a lock.

The disadvantages of the above structures, as well as most of the known structures having a seal on the outer surface of the nipple, are: loss of tightness due to aging of the sleeve material; and the fact that a coupling having a diameter of a obviously larger sleeve diameter and decreasing by compression to a smaller one will tend to return to the original due to internal high pressure. All this reduces the reliability of the hermetic connection in the areas of the end fitting of the sleeves, especially at high pressures in hydraulic systems.

The problem to which the invention is directed, is to prevent the expansion of the coupling housing (conical deformation) and depressurization of the connection, jamming of the packer when passing through the well. In order to prevent these defects, leading to slipping of the end fittings and ensuring the tightness of the connection when the sealing element is operating under internal pressure while maintaining the original dimensions of the end seal after removing the internal pressure under repeated loads, the coupling is made of durable high-quality steel, which is subjected to subsequent heat treatment by quenching.

These tasks are solved due to the fact that the sealing element to the hydraulic inflatable packer includes an inflatable part made in the form of a hollow cylinder, with connecting metal end fittings consisting of a nipple and a coupling, the coupling is mounted outside, and the nipple is installed inside, the inflatable part includes an internal sealing a layer of oil-resistant rubber, at least one paired strength layer of intercrossing wound at an angle of 24-26 degrees to the axis of the steel brass-plated spring wires an intermediate rubber layers are laid between the layers of the wire, one paired layer of cord nylon fabric superimposed on the wire layers at an angle of 24-26 degrees, on which the outer protective sealing rubber layer is applied, while the coupling is made of structural alloyed steel followed by thermal processing by the method of quenching, while on the inner surface of the coupling and the outer surface of the nipple there are annular grooves and protrusions that form a tongue-and-groove joint during assembly.

The tasks are also solved by developing a method for manufacturing a sealing element for a hydraulic inflatable packer, which includes assembling the end fittings on the pre-prepared blank of the inflatable part, namely placing the coupling on the nipple, between which the inflatable part is located, and in front of the coupling nozzle and nipple on one of of the ends of the inflatable part, a mandrel is installed, the shank of which is brought out through the central opening of the nipple and the tip having an outer diameter larger than the inner diameter the nipple is in front of the nipple, pulling the mandrel with the help of the translational movements of the machine.

The use of heat-treated couplings fundamentally changes the principle of fixing the end fittings on the sealing element. The pinching of the rubber-metal sleeve between the coupling and the nipple is not done by crimping the coupling with a decrease in the outer diameter to the diameter of the rubber-metal sleeve, but by increasing the internal diameter of the nipple using a special tooling through the nipple.

The technical result provided by the above set of features is an increase in the reliability of the design, leading to the possibility of multiple use of the device (packer) and restoring the original dimensions after removing the internal pressure without permanent deformation. The claimed packers withstand a pressure drop of 15-25 MPa.

The considered sealing element of an inflatable packer is essentially an inflated elastic rubber-metal sleeve at both ends of which there is an integral connecting metal fittings. An inflatable packer equipped with such a sealing element is operable under the conditions of high pressure drops, high mechanical loads and in various thermal and corrosive environments with the creation of a hermetic seal with high contact pressure on the wellbore.

The rubber-metal sleeve of the sealing element consists of the inner and outer rubber layers with increased abrasion resistance, coupled with resistance to the influence of working media, a power frame and fabric gaskets. The power frame of the sleeve contains several paired winding intersecting layers of steel brass-plated high-strength spring wire, between the layers of the wire superimposed intermediate rubber layers, while eliminating the possibility of chafing power elements. The use of wire with a brass surface increases the solidity of the wall of the sleeve due to improved connection with rubber structural elements. The coiling power layer has sufficient flexibility and deformation capacity for the necessary compaction of possible irregularities when packing open hole boreholes. To prevent the extrusion of rubber layers between the strands of wire under the influence of external and internal pressure, a coarse textile layer of smeared rubber mixture is induced on the coiling wire skeleton of the sealing element. Fabric gaskets also perform protective functions when a packer passes through uncased boreholes, ensuring the stability and mechanical strength of the sealing element to the action of multiple bending deformations.

To ensure the performance of the sealing element of the packer with a uniform perception of the applied repeated static and dynamic loads with repeated deformations with the restoration of the original size after removing the internal pressure and preserving the original adhesive bonds without interlaminar delamination, the power coiling wire and fabric layers of the rubber metal sleeve are applied at a single angle to the longitudinal axis . The monolithic construction is achieved by applying at various stages of the technological process in a certain sequence of materials, the surface of which enters into intermolecular interaction during subsequent vulcanization.

When the sealing element expands under the influence of internal pressure, the end fittings are also subjected to tensile loads, which can lead to the deformation of the coupling housing and depressurization of the joint, jamming of the packer as it passes through the well. In order to prevent these defects, leading to slipping of the end fittings and ensuring the tightness of the connection when the sealing element is operating under internal pressure while maintaining the original dimensions of the end seal after removing the internal pressure under repeated loads, the coupling is made of durable high-quality steel, which is subjected to subsequent heat treatment by quenching.

The use of heat-treated couplings fundamentally changes the principle of fixing the end fittings on the sealing element. The pinching of the rubber-metal sleeve between the coupling and the nipple is not done by crimping the coupling with a decrease in the outer diameter to the diameter of the rubber-metal sleeve, but by increasing the internal diameter of the nipple using a special tooling through the nipple. This reinforcement method allows you to achieve a minimum diameter difference on the outer and inner surface of the sealing element at the junction of the end fittings and the rubber metal sleeve, while increasing the flow area of the sealing element and increasing the flow around the outer surface as the packer passes through the open hole

The invention is illustrated by drawings, which depict:

figure 1 - sealing element to the hydraulic inflatable packer;

figure 2 - the design of the layered material of the inflatable part,

figure 3 - - shows the end fittings (coupling, nipple) assembled with an inflatable part to fix;

figure 4 - shows the process of fixing the end fittings,

Where

1 - inflatable part

2 - coupling

3 - nipple

4 - layer of oil-resistant rubber

5 - wire layer

6 - a layer of cord nylon fabric

7 - rubber layer

8 - mandrel.

The inflatable packer is a hollow rubber-metal cylinder (inflatable part) 1 with connecting metal end fittings consisting of a nipple 3 and a coupling 2 (figure 1).

The inflatable part 1 of the packer is a multilayer material (figure 2), which includes layers: an inner sealing layer of oil-resistant rubber 4, at least one paired strength layer 5 of intersecting wound at an angle of 24-26 ° to the axis steel brass-plated spring wires, intermediate rubber layers are laid between the layers of the wire, one paired layer of cord nylon fabric 6 is applied to the wire layers at an angle of 24-26 °, the outer protective rubber sealing layer 7 is applied to the fabric.

Used in the manufacture of rubber ensure the solidity of the design of the inflatable part 1, winding of the power layers and the imposition of fabric at an angle of 24-26 ° ensure the restoration of the original dimensions of the packer after removing the internal pressure.

At both ends of the inflatable part 1, the metal end fittings are fixed, consisting of nipple 3 and coupling 2. In order to achieve this goal, in the claimed invention, coupling 2 is made of structural alloyed steel with subsequent heat treatment by quenching. In this case, the coupling is mounted on the outside, the nipple is installed inside. On the inner surface of the coupling and the outer surface of the nipple there are annular grooves and protrusions that form a tongue-and-groove connection during assembly, which ensures a reliable clamping of the ends of the inflatable part between the component parts of the end fittings by increasing the flow area when pulling through the mandrel nipple 8 with the outer diameter larger than the internal diameter of the nipple.

The device is manufactured (assembled) as follows. After making the material for the inflatable part, the blanks are cut to the required length. Next, the end fittings are assembled on the inflatable part 1. A mandrel 8 is installed inwards at one of the ends of the inflatable part 1, the coupling 2, the nipple 3 are mounted, and the shaft of the mandrel 8 is pulled out through the central hole of the nipple 3 (Figure 4), and the tip mandrel 8 having an outer diameter larger than the inner diameter of the nipple 3 remains in front of the nipple inside the inflatable part 1. With the aid of a machine with a hydraulic drive of the translational movement, the dorn 8 is pulled out, as a result, the nipple 3 is unclamped and firmly presses the inflatable tea to the clutch 2. With this design at the working pressure of the packer (inflation of the elastic insert) in the open borehole, the coupling housing is not deformed, there is no deformation in the form of a cone, i.e. no skirt is formed, which makes it difficult for the packer to ascend or descend into the well, and it can also be destroyed if it engages on the destroyed sharp edges of the rock.

The claimed packer design provides multiple use, restoring the original dimensions after removing the internal pressure without permanent deformation, withstands a pressure differential of 15-25 MPa.

Claims (2)

1. Sealing element to the hydraulic inflatable packer, comprising an inflatable part made in the form of a hollow cylinder, with a connecting metal end fittings consisting of a nipple and a coupling, the coupling is mounted outside, and the nipple is installed inside, characterized in that the inflatable part includes an inner sealing layer at least one paired strength layer made of oil abrasion resistant rubber made of intersecting ones wound at an angle of 24-26 degrees to the axis of steel brass-plated spring wires, and Between the layers of wire, intermediate rubber layers are superimposed, one paired layer of cord nylon fabric superimposed on the outer protective sealing rubber layer is applied to the wire layers at an angle of 24-26 degrees, while the coupling is made of structural alloy steel, followed by heat treatment by quenching, at the same time on the inner surface of the coupling and the outer surface of the nipple there are annular grooves and protrusions that form a tongue-and-groove joint during assembly. 2. A method of manufacturing a sealing element according to claim 1 to a hydraulic inflatable packer, comprising assembling the end fittings on the preformed inflatable part blank, namely fitting the coupling onto the nipple, between which the inflatable part is located, while in front of the coupling nozzle and nipple at one of the ends the inflatable part is fitted with a mandrel, the shank of which is brought out through the central hole of the nipple, and the tip having an outer diameter larger than the internal diameter of the nipple is in front of the nipple, Dave with the help of the translational movements of the machine.

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