RU2720714C1 - Well head for pressure release - Google Patents

Abstract

FIELD: oil, gas and coke-chemical industries.

SUBSTANCE: invention relates to oil and gas industry, namely to devices of wellhead equipment for protection against emergency pressure drops between annular space of well and discharge line in both directions. Well pressure valve for pressure release contains housing with channel equipped with seat and shutoff element spring-loaded from stop to seat, which passes from annular space into discharge line. Housing is equipped with an additional channel equipped with an additional seat and an additional element spring-loaded from the stop to this seat, which passes from the discharge line to the annular space. Force of locking elements pressing to seats is selected so that to exclude pressure difference exceeding emergency value for corresponding structural elements of wellhead equipment.

EFFECT: technical result is improved reliability of wellhead equipment protection against emergency pressure drops due to possibility to automatically release pressure from well annulus into discharge pipeline in automatic mode or vice versa.

1 cl, 2 dwg

Description

The invention relates to the oil and gas industry, and in particular to methods of protection and devices for wellhead equipment, namely, to protect against emergency pressure drops between the annulus of the well and flow line in both directions.

Known combined ball valve (patent for PM RU No. 162471, IPC F16K 5/06, published on June 10, 2016 in Bull. No. 16), comprising a ball valve housing with a central through hole, a housing cover, a ball plug with a central through hole fixed inside the body by saddles, a stem, a handle, a check valve, and in the central through hole of the ball plug there is a check valve with a valve located inside it, a stem with a thrust sleeve and a spring placed on it, while in the thickened part of the check valve body Nena longitudinal through holes hydraulically connected with a central through bore and the check valve of the ball valve, and the combined ball-cock valve mounted on the flowline wellhead.

This device provides a method of protecting wellhead equipment from emergency pressure drops between the annulus of the well and the flow line in one direction, depending on the position of the ball plug of the valve relative to the mouth.

The disadvantages of this method are the complexity of manufacturing associated with the placement of the valve on the ball plug, the need for constant monitoring of pressure surges for timely rotation of the ball plug in the right direction, in cases of untimely switching of the valve-valve, there is a high probability of accidents from the side of closing the valve in the annulus of the well or flow line .

The closest in technical essence is a method of protecting flow wells of pipelines from solidification in the fields of abnormal oils (patent RU No. 2282102, IPC F17D 1/00, published on 08.20.2006 in Bull. No. 23), which includes replacing the produced products in the flow pipeline with low viscosity non-curing agent, and when the well stops, the annular valve on the wellhead valve is opened, gravity is drained from the flow pipe into the annular space of the well, the fluid is replaced by annular gas, and before the start of the well, the annular valve is closed, the annular space of the well is connected to the flow pipeline through a non-return valve installed on the line connecting the flow line with the annulus.

The disadvantage of this method is the narrow scope due to the inability to automatically relieve pressure from the flow line, the need for constant monitoring of pressure surges in the flow line for the timely opening of the corresponding valve, in cases of untimely opening there is a high probability of accidents associated with a rupture of the pipeline.

The technical task of the proposed invention is the creation of a reliable method of protecting wellhead equipment from emergency pressure drops, which allows automatically to relieve emergency pressure from the annular well into the flow line or vice versa.

Known check valve (patent for PM RU No. 127808, IPC E21B 34/06, E21B 33/14, published on 05/10/2013 in Bull. No. 13), containing a hollow body with a seat, a locking element placed in it, and the body is made in in the form of an integral cylindrical structure with a spring-loaded plunger installed in it with the possibility of passing the flow of the solution only to the face, while the locking element of the plunger is made in the form of a spherical locking tip.

The closest in technical essence and the achieved result is a gas check valve (patent RU No. 2465437, IPC E21B 34/00, published on 10/27/2012 in Bull. No. 30), comprising a housing and a valve assembly including a spring-loaded shut-off element with a rod, having a fixed connection with the washer, and the housing is installed in the interflange space of the tube head and has annular sealing protrusions for the corresponding sealing grooves, made in the form of seats for accommodating the said annular sealing protrusions in places of the flange connection, the valve assembly comprises a non-metallic sleeve hermetically connected to the housing by means of a detachable connection, while between the housing and the sleeve an elastic ring is installed for sealing, and the sleeve is made with an internal conical surface with which the spring-loaded locking element is sealed in contact, having an accordingly external conical surface.

The disadvantages of both valves are that they let in only one direction, because of this they do not protect against excessive pressure from the closing side, which can lead to gusts of the latter.

The technical task of the proposed invention is the creation of a wellhead valve design for pressure relief, which allows to protect from emergency pressure drops in the annular space of the well and fluid in the flow line of the wellhead equipment.

The technical problem is solved by the method of protecting wellhead equipment from emergency pressure drops, including providing a connection between the annulus of the well and the flow line through a valve installed on the line connecting the flow line to the annular space.

What is new is that the valve is made of double-sided action, due to which liquid is drained from the discharge pipe into the annulus with a sharp increase in pressure in it before an emergency pressure drop.

The technical problem is also solved by a wellhead valve for pressure relief, comprising a housing with a channel equipped with a seat and a locking element spring-loaded from stop to seat, passing from the annulus into the flow line.

What is new is that the casing is equipped with an additional channel equipped with an additional seat and an additional locking element, spring-loaded from the stop to this seat, passing from the flow line into the annulus, and the force of pressing the locking elements to the seats is selected so as to exclude a pressure differential that is superior to the emergency corresponding structural elements of wellhead equipment.

In FIG. 1 shows a diagram of a wellhead valve in longitudinal section.

In FIG. 2 shows the installation diagram of the wellhead valve in the wellhead equipment.

The wellhead valve for depressurizing comprises a housing 1 (Fig. 1) with a channel 2 equipped with a seat 3 and a locking element 4, preloaded by a spring 5 from the stop 6 to the seat 3 and letting the borehole 8 from the annular space 7 (Fig. 2) into the flow line 9. The housing 1 (Fig. 1) is equipped with an additional channel 10, equipped with an additional seat 11 and an additional locking element 12, pressed by an additional spring 13 from its stop 14 to this saddle 11 and passing from the flow line 9 (Fig. 2) into the annulus 7. The pressing force of the corresponding springs 5 (Fig. 1) and 13 of the locking elements 6 and 12 to the corresponding seats 3 and 11 are selected so as to exclude a pressure differential between the flow line 9 (Fig. 2) and the annulus 7, which is superior to the emergency for the corresponding structural elements 9 and 7 of the wellhead equipment 15. Adjustment the pressing force of the springs 5 (Fig. 1) and 13 can be carried out by moving the corresponding stops 6 and 14 along the threads 16 and 17 (selected empirically).

Structural elements and process connections that do not affect the operability of the valve and wellhead equipment in FIG. 1 and 2 are not shown or shown conventionally.

A method of protecting wellhead equipment from emergency pressure drops is implemented as follows.

Well 8 (Fig. 2) is provided with an elevator pipe string 18 and wellhead equipment 15, the in-pipe space 19 and the annular space 7 communicate with a flow line 9. A well valve with a housing 1 is installed between the flow line 9 and the annular space 7. Moreover, the well valve is manufactured as a double-acting valve, due to which the liquid is drained from the flow line 9 into the annular space 7 with a sharp increase in pressure in it before an emergency pressure drop, as well as gas discharge from the annular space 7 into the wake bottom pipe 9 with a sharp increase in gas pressure inside this space 7 to the emergency pressure drop. In the absence of pressure surges on both sides of the wellhead valve, the annular space 7 is not communicated to the discharge pipe 9.

When draining the liquid from the flow line 9, the locking element 4 (Fig. 1) is squeezed from the seat 3, and when the gas is discharged from the annulus 7 (Fig. 2), the additional locking element 12 (Fig. 1) is squeezed from its seat 11.

The proposed methods for protecting wellhead equipment from emergency pressure drops and the wellhead valve for pressure relief are simple, reliable, and can protect from emergency pressure drops in the annulus of the well and fluid in the flow line of the wellhead in automatic mode (without human intervention).

Claims (1)

Wellhead valve for pressure relief, comprising a housing with a channel equipped with a saddle and a shut-off spring-loaded element from the stop to the saddle, passing from the annulus to the flow line, characterized in that the housing is equipped with an additional channel equipped with an additional seat and an additional spring-loaded shut from the stop to this the saddle with an element passing from the flow line into the annulus, and the force of pressing the locking elements to the saddles is chosen so as to exclude a pressure drop exceeding the pressure yny for the respective structural elements of the wellhead.

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