RU2591309C2 - Downhole gas bypass valve - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: valve includes connected on both ends with tubing string coupling with side hole, where valve body is built with bypass hole. Body is made in form of stepped cylinder, and in said cylinder there are coaxially arranged in series a nut with central stepped hole and a sharp end edge, spring-loaded slide valve with longitudinal channels on periphery, a sealing gasket and locking element in form of a bolt with a conical tip. Slide valve with sealing gasket can interact with face edge of nut, and shutoff element, simultaneously holding sealing gasket on slide valve, on closing bypass holes of body limits stroke and further compression spring. Body with outer side is equipped with top and bottom vertical gusset plates. Slide valve, spring and valve shutoff element are made of stainless material and sealing gasket is made from polyurethane.

EFFECT: higher efficiency of device for gas bypass.

2 cl, 1 dwg

Description

The invention relates to underground downhole equipment and can be used in the operation, development, killing and flushing of oil wells during operations associated with gas bypass from the annulus of the well into the tubing string.

A device for discharging gas from the annulus, consisting of a submersible motor, a centrifugal pump and an ejector device including a nozzle, a mixing chamber and a diffuser, is known. At the level of the mixing chamber, a channel for bypassing gas from the annulus, equipped with a check valve, is made. When the pump is operating, the produced fluid is directed through the nozzle, creating a vacuum in the region of the mixing chamber, causing the valve to open and bypass gas from the annulus to the region of the mixing chamber. Gas, mixed with the produced fluid, enters the diffuser and then rises at the wellhead (RF patent No. 2079636, class E21B 43/00, publ. 05.20.1997).

This device is applicable only in conjunction with a centrifugal pump and is operable only when the pump is operating with a stable operation of the ejector pump, which further complicates the downhole equipment.

A device is known for transferring gas from the annulus of the well into the tubing string, including a body connected at both ends to the tubing and with through radial holes that are covered by a sleeve mounted on a threaded leaky connection outside the housing (RF patent No. 2074954, class. E21B 43/00, E21B 43/12, publ. 03/10/1997).

The known device provides the bypass of gas and liquid in the forward and reverse direction without the possibility of stopping the passage and adjusting the flow of gas and liquid through the device.

The closest to the invention in essence is a device for bypassing gas from the annulus to the tubing string, including a coupling with a lateral hole connected at both ends to the tubing, to which the housing is connected. The casing is provided with a longitudinal channel connecting to each other and a side hole combined with the side hole of the coupling. A fitting and a check valve with a filter are located in the longitudinal channel of the housing. The non-return valve provides gas bleeding with increasing pressure in the annular space above the pressure in the tubing string by 0.1-0.2 MPa. At the same time, the device provides a reduction in flow rate during fluid circulation by no more than 10% (RF patent No. 2303124 C1, CL EV 43/12, publ. July 20, 2006, prototype).

The known device, along with gas bypass, also provides liquid bypass from the annulus to the tubing string during flushing and killing of the well, which reduces the efficiency of the killing and backwashing of the well during repair work.

The proposed invention solves the problem of increasing the efficiency of the device for transferring gas from the annulus to the tubing string by eliminating the circulation of fluid through the valve device when killing and flushing the well.

The problem is solved in that in the downhole gas bypass valve, including a coupling with a lateral hole connected at both ends to the tubing, where the valve body with a bypass hole is integrated, according to the invention, the housing is made in the form of a stepped cylinder and a nut is placed in series with it in series with a central stepped hole and a sharp end edge, a spring-loaded spool with longitudinal channels on the periphery, a gasket and a locking element in the form of a bolt with a conical end, and the spool with the gasket has the ability to interact with the end edge of the nut, and the locking element that simultaneously holds the gasket on the spool, when locking the bypass hole of the housing limits the stroke of the valve and further compression of the spring, while the housing is provided with an upper and lower vertical kerchiefs. The spool, spring and valve closure are made of stainless material and the gasket is made of polyurethane.

In FIG. 1 shows the proposed downhole valve for gas bypass in longitudinal section.

The proposed downhole valve is installed in the estuary of the tubing string, i.e. between the first and second or second and third pipes from the mouth.

The downhole valve consists of a sleeve 1 with a side hole 2 connecting the tubing 3 and 4. A stepped cylindrical valve body 5 with a bypass hole 6 made at its bottom is built into the side hole 2. A nut 7 is wrapped in the housing 5 with a stepped hole 8, a sharp end edge 9 and a turnkey hexagon socket 10. Under the nut 7 in the housing 5, a spring-loaded spool 11 with a polyurethane gasket 12 and longitudinal channels 13 is located. In this case, the spring 14 is located between the spool 11 and the bottom of the valve body 5, and the locking element 15 holding the gasket 12 has a conical tip 16. When Using the nut 7, the force of the spring 14 is adjusted to actuate the spool 11 with the corresponding pressure drop in the valve. The valve body 5 from the outside has a lower 17 and upper 18 welded vertical protective scarves that protect the valve body during tripping operations with downhole equipment. The downhole valve operates as follows.

When operating an oil well in the annulus, i.e. in the space of the estuarine part of the well between the casing and tubing string, gas accumulates. With an increase in gas pressure in the annulus above the pressure in the tubing string 3 and 4 by 0.1-0.2 MPa (pre-set in bench conditions), the spool 11 with the gasket 12, pressing the spring 14, slightly moves away from the end edge 9 of the nut 7, creating a space for gas to flow from the hole 8 of the nut 7 into the internal cavity of the valve. When this gas through the longitudinal channels 13 and the bypass hole 6 enters the inner cavity of the coupling and the tubing string, and then the upward flow of fluid is sent to the flow line of the well. With increasing pressure in the annulus and exceeding the pressure drop in the valve by more than 0.3 MPa, which can occur when flushing the downhole pumping equipment or killing the well by the backwash method. At the same time, due to the large hydraulic resistance of the flushing liquid in the spool 11, its maximum movement occurs and with it the locking element 15, the conical tip 16 of which closes the bypass hole 6, at the same time prevents further pressing of the spring 14 and ensures the termination of the fluid circulation through the valve.

The proposed downhole valve, along with providing gas bypass from the annulus during well operation, also increases the efficiency of the process of killing and flushing the well by preventing the circulation of flushing fluid through the valve during repair work and eliminates unjustified flow of flushing fluid.

Claims (2)

1. A downhole valve for gas bypass, including a coupling with a lateral hole connected at both ends to the tubing, where the valve body with a bypass hole is integrated, characterized in that the housing is made in the form of a stepped cylinder and a nut with a central a stepped hole and a sharp end edge, a spring-loaded spool with longitudinal channels along the periphery, a sealing gasket and a locking element in the form of a bolt with a conical tip, and The IR with the gasket has the ability to interact with the end edge of the nut, and the locking element that simultaneously holds the gasket on the spool, when the spool is in the extreme open position, closes the bypass hole of the housing and limits further compression of the spring, while the housing is provided with an upper and lower vertical protective scarves. 2. The downhole valve according to claim 1, characterized in that the spool, spring and valve shutoff element are made of stainless material, and the gasket is made of polyurethane.