RU2463438C1 - Method of heating check valve shutoff element - Google Patents

Abstract

FIELD: oil-and-gas production.

SUBSTANCE: proposed method consists in forcing warm extracted medium, for example, reservoir fluid with temperature of 15-25° over outer shaped surface of intenral unit accommodating shutoff valve. Shut off element consists of fixed and moving parts interacting over common equidistance surface and is made up of, preferably, of seat with spring-loaded disc arranged in inner unit case. Valve body has inlet branch pipe and hydrocarbon product discharge branch pipe and cover arranged on body rear. In keeping required temperature of inner unit, it is isolated from valve body by nonmetallic, preferably, rubber mix ring seals. Note here that, additionally, heat losses are reduced by making air chamber between inner unit face and valve body cover.

EFFECT: higher reliability of valve operation.

2 dwg

Description

The invention relates to valves for the gas industry, is intended for automatic discharge of fluid flow coming from a gas well during unauthorized gas emissions, and can be used in the development and creation of heated check valves and methods for heating them installed in tubing.

One of the problems encountered during the operation of the non-return valve is the provision of reliable heating of the contact area between the clan plate and the seat, as at negative ambient temperatures, moisture condenses from the discharged stream on the contact surfaces of the plate with the seat, which leads to incomplete closing of the valve and its subsequent failure.

Known check valve containing a housing with connecting flanges, a locking element in the form of a saddle with a spring plate installed inside the housing along the line of the component to be discharged (Non-freezing wellhead check valve 209AF.16.000 manufactured by OJSC AK Corvet 640046, Russia, Kurgan, ul. . Burova-Petrova, 20).

The specified valve operates as follows. The main component stream flows through the nozzles and heats the plate with valve seat. The discharged component, which comes under a greater pressure than the main one, opens the plate and is discharged into the formed gap.

The main disadvantages of this valve is that the plate is located directly in the oil stream and has a significantly larger working surface area than the area of the passage section of the channels for gas discharge.

Thus, to open the valve, it is necessary to apply pressure from the gas side to overcome the dynamic and static pressures of the oil flow acting on the plate and the force of the compression spring, which leads to the need for a significant pressure difference between the working and discharged flows. A significant pressure drop leads to failure of the equipment installed on the line.

A known method of heating the shut-off element of a non-return valve and a non-return valve, by which this method is implemented, comprising a housing with connecting pipes for a main component, for example oil, and a discharge component, for example a mixture of oil and gas, a locking element in the form of a saddle with a spring-loaded plate, installed inside the housing, along the line of the component to be discharged, a cavity is made above the plate connected by channels to the internal cavity of the housing, the channels opening downstream, enclosing passing in warm production medium, for example, oil well products, such as formation fluid, having a temperature of 15-25 ° C, on the outer profiled surface of the indoor unit, in which the valve shut-off body is located in the form of a seat and a spring plate (RF Patent No. 2337264, IPC: E21B 34/02, E21B 33/03 - prototype).

The specified method is implemented as follows.

The flow of oil, passing through the cavity in the body, flows around the valve seat and heats it together with the plate. In addition, part of the main oil flow enters through the channels into the cavity above the valve plate and additionally heats the sealing place of the valve seat and plate, thus ensuring the required temperature of the structure and the tightness of the sealing place. When a gas mixture arrives from a well having a higher pressure than the pressure of the oil stream, the plate moves along the axis under the action of the gas stream, the gas stream is discharged through the gap between the plate and the saddle into the cavity. From the cavity, through the channels, the flow enters the cavity of the housing and is discharged downstream. Thus, the pressure of the discharged flow decreases and the spring-loaded plate sits on the saddle. When dropping a stream having a lower temperature than the main stream, part of the condensate condenses on the sealing surfaces of the seat and plate. After the flow is discharged, part of the oil enters the cavity through the channels and heats the seal, which allows the condensate to melt and provide the required valve operating conditions.

The main disadvantage of this method of heating the valve shutter element is that at significant negative ambient temperatures, the shutter element is cooled to negative temperatures due to the heat conductivity between the valve parts located inside the valve and outside, while the warm oil flow does not have time to warm it up to positive temperatures, especially at intermittent wells. When wet gas comes into contact with the surfaces of the sealing elements, condensate settles at a lower temperature, which at low ambient temperatures leads to the formation of ice on the sealing surfaces of the plate and seat and the valve is out of order.

The technical task of the invention is to eliminate these drawbacks and create a method for heating the non-return valve, which allows it to be opened with the lowest possible pressure difference between the flows with the exception of the possibility of condensation on the sealing surfaces due to its constant heating by the oil flow and reduction of heat loss.

The solution to this problem is achieved due to the fact that in the proposed method of heating the shut-off element of the non-return valve, which consists in passing a warm produced medium, for example, the production of oil wells, such as formation fluid having a temperature of 15-25 ° C, along the outer profiled surface of the indoor unit, in which a locking element of the valve is arranged, consisting of fixed and movable parts interacting with each other on a common equidistant surface, made preferably in the form of a saddle with a spring-loaded plate, and installed in a hollow valve body having an inlet and an outlet for producing hydrocarbon wells and a cover installed on its back, according to the invention, while maintaining the temperature of the indoor unit in the required range of values, the indoor unit is insulated from the valve body using non-metallic, preferably made of rubber compounds, ring seals, while further reducing heat loss by performing between the end face of the indoor unit with a locking element cop and cover the body of the gas cavity, mainly air.

Comparative analysis with the prototype shows that in the proposed method, in contrast to the structural design of the prototype, the housing of the indoor unit is thermally insulated due to the implementation of the gas cavity from interaction with the environment, which can significantly reduce losses associated with heat conduction and heat exchange of the external and internal parts of the valve with each other.

Thus, the set of essential features of the claimed technical solution due to the presence of new features provides a technical result, which is expressed in increasing the reliability of the valve without significantly complicating its design.

The design solution of the device makes it possible to use the proposed valve in areas with low ambient temperatures, which can significantly reduce the range and number of valves used when servicing the well, reduce the time and cost of servicing them, and thereby reduce the time for servicing the well during repair work.

These essential features, together characterizing the essence of the claimed technical solution, are not currently known for regulatory devices. The analogue, characterized by the identity of all the essential features of the claimed invention, was not found during the studies, which allows us to conclude that the claimed technical solution meets the criterion of "Novelty."

The essential features of the claimed invention cannot be represented as a combination identified from known solutions with the implementation in the form of distinctive features to achieve a technical result, from which it follows that the criterion of "Inventive step" is met.

Due to the fact that the described technical solution is intended for use within a real gas well piping system in case of an emergency increase in pressure, it was manufactured by the applicant and tested to achieve the claimed technical result, the invention meets the criterion of "Industrial applicability".

The essence of the proposed technical solution is illustrated by drawings, in which Fig. 1 shows a longitudinal section of the proposed reverse heated valve for implementing the specified method, Fig. 2 is a cross section of the proposed reverse heated valve for the implementation of this method.

The main elements of the proposed valve are:

1 - housing;

2 - connecting pipe;

3 - connecting branch;

4 - locking element;

5 - fixed part of the locking element;

6 - movable part of the locking element;

7 - indoor unit;

8 - cavity;

9 - channels;

10 - a cover;

11 - ring seal;

12 - thrust;

13 - end of traction;

14 - profiled end of the thrust;

15 - gas cavity;

16 - clearance.

The proposed method can be implemented using a valve having the following design.

The non-return valve comprises a housing 1 with connecting nozzles 2 for the main component, for example oil, and the discharge component 3, for example, a mixture of oil and gas. The locking element 4, consisting of a fixed 5 and a movable 6 parts, interacting with each other on a common equidistant surface, made preferably in the form of a saddle with a spring plate. The locking element is placed in the housing of the indoor unit 7, mainly representing a profiled body of revolution, preferably a cylinder mounted inside the valve body along the line of the component to be dropped. The longitudinal axis of the locking element 4 is perpendicular to the axis of the pipe 3 of the discharge component. Above the plate 6, a cavity 8 is made, connected by channels 9 to the internal cavity of the valve body 1. Channels 9 open downstream. In the reciprocal part of the valve body 1, a cover 10 is installed that fixes the indoor unit 7 with the locking element 4 from movement. The indoor unit 7 is insulated from the valve body 1 by means of non-metallic ring seals 11. At the end of the body of the indoor unit 7 facing the cover 10, a rod 12 is installed, mainly cylindrical, interacting with the end body of the indoor unit 7 at one end 13, the other 14, preferably profiled, - with the inner surface of the cover 10 of the valve body 1, made in the form of a hollow cylinder with one closed end, with the formation inside the cover 10, between the end of the cover and the end of the indoor unit 7, a closed gas cavity and 15, mainly air, while between the supporting surface of the cover and the end face of the indoor unit there is a gap 16.

The proposed method is implemented as follows. The oil flow, passing through the cavity in the housing 1, flows around the valve seat 4 and heats it together with the plate 5. In addition, part of the main oil stream enters through the channels 7 into the cavity 6 above the valve plate 5 and additionally heats the seal seat of the valve 4 and plate 5, thus providing the required temperature of the structure and the tightness of the seal.

Upon receipt of the gas mixture from a well having a higher pressure than the pressure of the oil stream, the plate 5 rises under the action of the gas stream, the gas stream is discharged through the gap between the plate 5 and the seat 4 into the cavity 6. From the cavity 6, through channels 7, the flow enters the cavity of the housing 1 and is discharged downstream. Thus, the pressure of the discharge flow decreases and the spring-loaded plate 5 sits on the saddle 4.

When dropping a stream having a lower temperature than the main stream, part of the condensate condenses on the sealing surfaces of the seat 4 and plate 5. After dropping the stream, part of the oil enters the cavity 6 through channels 7 and heats the seal, which allows the condensate to melt and provide the required conditions valve operation.

When the valve is operating, the housing of the indoor unit 7 warms up under the action of the warm flow of the produced fluid. Due to the fact that at the end of the housing of the indoor unit 7 facing the cover 10, a rod 12 is installed, mainly cylindrical, with one end 13 interacting with the housing of the indoor unit 7, the other 14, preferably profiled, with the inner surface of the cover 10 of the valve body 1 and holding the housing of the indoor unit 7 from movement, there is a significant reduction in heat loss by reducing heat transfer between the indoor unit 7 and the surrounding atmosphere. The presence inside the lid 10, between the end of the lid and the end of the indoor unit 7, of a closed gas cavity 15, mainly air, also reduces heat loss. Also, to eliminate heat loss between the supporting surface of the cover 10 and the end face of the indoor unit 7, a gap 16 is made.

Using the proposed technical solution will expand the range of flow rate of the transported medium, increase the service life of the shut-off element, reduce the number of valves used when servicing the well, reduce the time and cost of servicing them, reduce the time for servicing the well during repair work.

Claims (1)

A method of heating a check valve shut-off body, which consists in passing a warm produced medium, for example, oil wells, such as formation fluid having a temperature of 15-25 ° C, on the outer profiled surface of the indoor unit, in which the valve shut-off element is located, consisting of a fixed and a moving part interacting with each other on a common equidistant surface, made preferably in the form of a saddle with a spring-loaded plate, and installed in a hollow valve body having an inlet and an outlet pipe for producing hydrocarbon wells and a cover mounted on its back side, characterized in that while maintaining the temperature of the indoor unit in the required range of values, the indoor unit is insulated from the valve body using non-metallic, preferably made of rubber mixtures, O-rings, reduce heat loss by performing between the end of the indoor unit with a locking element and the cover of the body of the gas cavity, mainly air.

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