RU191354U1 - CHECK VALVE - Google Patents

Abstract

The utility model relates to the field of valve engineering, in particular to fountain valves, designed to prevent the backflow of medium in field pipelines after venting excess gas pressure from the annulus, and is intended to be used in combination with wellhead valves during oil production, mainly at low temperatures. The non-return valve contains a cylindrical body with an opening for the passage of liquid and gas, a shut-off element in the form of a ball placed in the saddle, while the non-return valve is placed parallel to the wellhead valves and is additionally equipped with a spring. In an aggressive environment, as well as in wells predisposed to the formation of paraffin deposits, the valve pair has a stellite or tungsten carbide coating. 1 s.p. f-ly, 1 Fig.

Description

The utility model relates to the field of valve engineering, in particular to fountain valves, designed to prevent the backflow of medium in field pipelines after bleeding excess gas pressure from the annulus, and is intended to be used in combination with wellhead valves for oil production, mainly at low temperatures.

Known universal wellhead well fitting (RF patent No. 36428, IPC Ε21B 33/03, publ. 03/10/2004), consisting of a housing, a pipe holder, a tee of a wellhead seal, as well as a gas outlet, flow line and an annulus with angle valves and a check valve, characterized the fact that it is equipped with a removable connection, on one end of which there is a union nut with an internal thread for the wellhead stuffing box tee, and on the other end there is a flange for fastening the valve, plug or lubricator, and the wellhead stuffing box tee is elongated in the lower part, and a wide bore hole is made in the pipe holder at an angle with a body with a blind cover installed in it, and if it is possible to operate an ESP well (electric centrifugal pump), this unit is a cable sealing unit, and the cover is made with a hole for cable entry, while for grounding and hardening the reinforcement design installed steel visor.

This wellhead reinforcement has a significant design flaw that adversely affects the operation of wells:

 the check valve for bleeding gas is located in the unheated zone, which leads to freezing and failure to work at low temperatures (in winter);

 the impossibility of servicing this valve during the spring thawing season with an increase in the water level of nearby rivers and flooding of the lower part of the wellhead fittings;

 no safety device is provided to prevent the rupture of the pipeline and preventing the spillage of the produced fluid into the adjacent territory of the well.

 additional material costs are required to attract special equipment for cleaning up oil contamination and steaming wellhead valves in the event of an oil pipeline rupture.

Known check valve for fountain valves (RF patent No. 34200, IPC Ε21B 34/02, publ. 11/27/2003), comprising a housing placed coaxially with the gravity vector directed normally to the valve seat located in the housing with a locking member and a limiter for its movement, and a flange for attaching the housing in the pipeline connecting the annulus of the well with the manifold pipe, characterized in that the flange is equipped with a normal nozzle to it, the length of which exceeds the length of the pipeline by the radius of the manifold pipe, and the saddle It resides on a side surface of the free end of the pipe with a plugged end manifoldnoy coaxially with the pipe.

The disadvantages of this check valve for fountain valves are:

 design complexity;

 the impossibility of using the AU-140 × 50 and AUE 140 × 50 type wellhead fittings in the above-described wellheads for oil production due to design features;

Known check valve (RF patent No. 2605685, IPC F16K 15/03 F16K 31/08, publ. 12/27/2016), the closest in technical essence and adopted as a prototype, comprising a housing with a hole, a seat, a pivotally connected shutter and permanent magnets. Permanent magnets are placed symmetrically to the vertical axis behind the ring installed in the end part of the housing and protruding beyond it with the formation of a gap. The magnets and the ring are aligned with the hole. The shutter pivotally connected to the housing is provided with a plate whose size exceeds the outer diameter of the ring. The ring and plate are made of lyophobic material. The width of the metal part of the shutter extending beyond the plate is equal to or greater than the diameter of the magnet. The end part of the body and the protrusion of the ring form a saddle.

The disadvantages of this check valve are:

 design complexity;

 a small cross-section, which complicates the process of flushing the bottom and killing the well by direct flushing (by supplying the process fluid to the tubing, creating a circulation with the annulus of the tubing and production string);

 location in unheated zone, leading to freezing and failure in operation at low temperatures.

These prototypes narrow the scope and are not universal.

The closest in technical essence is a cylindrical ball valve (RF patent No. 77930, IPC F16K 15/04, published on November 10, 2008 in Bull. No. 31), comprising a housing with a seat, a ball located in a stepped passage channel and a spring interacting through a supporting element with a ball, the supporting element being in the form of a cylinder and configured to interact with the inner surface of the channel to limit the stroke length in the open position and to create a gap between the supporting element and the ball in the closed position of the valve.

The disadvantages of this device are the low reliability in the winter and what cannot be used as part of wellhead fittings without special preparation.

The objective of the proposed utility model is to increase the reliability of the non-return valve, to ensure normal conditions when killing and flushing the well, to increase the operational characteristics of wellhead fittings, to ensure annular gas bleeding, to ensure trouble-free operation of the well and, as a result, to increase the overhaul period.

The problem is solved as follows. A non-return valve installed on the manifold line (1), comprising a body (2) with an internal thread, a locking member in the form of a ball (3) with a seat (4) and a spring (5). To connect to the manifold line (1) in the check valve body (2) there is an internal metric thread on both sides. As a locking element, it is possible to use a valve pair (ball and seat) of the pump 20 (25) -175-RHAM or 25-225-TNM depending on the diameter of the manifold line from 60 mm to 73 mm.

The device operates as follows. During the operation of the well, when the pressure in the annulus exceeds the pressure of the manifold line 1 of the wellhead fittings by 1-2 atm., The associated gas lifts the ball 3, compressing the spring 5, and through the cylindrical hole in the seat 4 through the inner space of the check valve body 2 enters the manifold line 1 of the wellhead reinforcement, thereby relieving pressure in the annulus (annulus) of the well. When the associated gas pressure decreases in the annular (annular) space of the well (equalizing the pressure in the tubing and annulus), the spring 5 unclenches, the ball 3 sits and closes the hole in the seat 4. The non-return valve operates in automatic mode. This allows you to ensure a constant liquid level, constant pressure in the annulus (annulus) space, preventing the backflow of the medium in the field pipelines.

As a result of the use of a ball with a seat as a locking member and the location of this device in a heated zone (close to wellhead fittings), the freezing and failure of the non-return valve in winter time is excluded, the increase in the flow area allows accidentally flushing and killing the well in the tubing . The presence of a non-return valve in visual visibility significantly reduces the risk of a rupture of the manifold line and pouring of produced fluid into the adjacent territory of the well.

This non-return valve is reusable in use, and during inspection and repair, it involves replacing a worn ball and seat. The simplicity of the design allows revision of the non-return valve during the operation of the well without removing it to a mechanical workshop by closing the angle valve and linear valve. The use of a check valve allows you to maintain an optimal dynamic level in the well, ensuring normal operation of the pump. The non-return valve is safe in operation for maintenance personnel and is aimed at preserving the ecology of the environment.

The non-return valve is universal, relieves pressure in the annulus (annulus) of the well and prevents the backflow of produced fluid into the well. In an aggressive environment, as well as in wells predisposed to the formation of paraffin for the greater effect, it is possible to use a valve pair (ball with seat) with a tungsten carbide coating.

Claims (1)

A non-return valve containing a cylindrical body with an opening for the passage of liquid and gas, a shut-off element in the form of a spring-loaded ball placed in the saddle, characterized in that the body is located in the manifold line of the piping of the wellhead valves, the ball is installed in the saddle with the possibility of gas passage from the annular well space, and the housing is installed parallel to the wellhead fittings and is located in the heated zone.

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