RU2656536C1 - Cutoff valve - Google Patents

Abstract

FIELD: measuring equipment; mining.

SUBSTANCE: invention relates to the formation fluid flow rate control devices in horizontal wells with steam-thermal action onto the formation. Device consists of detachable housing, in the axial channel of which a fixed seat is installed, in which a nut with ribs is arranged. Above the seat bushing with bottom in the middle part is installed. Under the bottom spring-loaded hollow plunger with pressed to the bottom poppet valve is installed. Inside the bushing installed are container with thermal expanding substance and pusher with an annular projection, passed through the central opening with mating boring, inside the hollow plunger cavity. Container is fastened inside the bushing with a nut and forms the annular gap with it, by the bypass holes hydraulically connected to the detachable housing axial channel. Bushing is provided with ribs, which enter into the detachable housing parts connection point. Through the adapter device is connected to the horizontal well pipe outlet end. With the heated to temperature of +60÷70 °C formation fluid supply though the device, the structural parts warming up takes place with the opened valve. With the gas-vapor mixture with a higher temperature breakthrough, the device further heating takes place, with increase in the thermal expanding substance volume, which leads to the pusher with hollow plunger displacement towards the seat, with the poppet valve seating onto it and termination of the gas-vapor mixture supply. Formation fluid accumulation takes place in the wellbore, with the structural parts cooling with decrease in the thermal expanding substance volume. Poppet valve moves away from the seat, followed by the formation fluid supply from the well. Mechanical impurities are removed from the valve cavity by the gas stream through the nipple.

EFFECT: proposed is the formation fluid flow rate control device in horizontal wells with steam-thermal action on the formation.

1 cl, 3 dwg

Description

The invention relates to devices for regulating the flow of formation fluid in horizontal wells developing a formation using thermal methods.

A known fluid flow regulator (see US Patent No. 4858644, published 05/31/1988), consisting of a hollow body with a stepped axial channel in which a spring-loaded piston with a fitting, based on a spring, which plays the role of a flow rate limiter, is placed. At the other end, the spring rests on a seat in the adapter in which the circulation holes are made to connect the axial channel of the hollow body with the channel of the adapter.

The operation of the device is as follows:

The working (reservoir) fluid, through the axial channel of the fitting, is fed into the axial channel of the piston and then into the cavity bounded by the coil of the spring, in the gap between which the fluid flows into the chamber surrounding the spring, and then through the holes in the body of the adapter is fed into its axial channel. By reducing the gap between the spring coils, the flow rate of the fluid changes.

This is achieved by moving the piston, with a change in differential pressure.

The regulator compensates for the fluid flow rate in automatic mode.

The disadvantages of the design include:

- limiting the flow rate of the fitting and the gap between the turns of the spring, depending on the pressure drop across the piston. In this case, the piston can make a reciprocating motion, with the position on the flow of pulses of flow and pressure, which determines the fluid flow rate unstable in time.

However, there is no possibility of a complete cessation of fluid supply.

The flow regulator cannot work with a small pressure drop, since the force exerted by the spring is not enough to return the valve to the seat.

Known hydrodynamic pressure pulsator (see RF patent No. 2212513, published September 20, 2003).

The invention is intended to impact on reservoirs and cleaning the bottom-hole zone of wells.

In the case with windows covered by a spring-loaded element, a saddle and a locking element are placed, which is made in the form of a spring-loaded piston located inside the sleeve. The piston cavity of the piston communicates continuously with the high pressure cavity. The supra-piston cavity is in communication with the pulsating pressure region through a damping hole in the lower housing cover and a spring-loaded bypass valve, which has the ability to adjust the hydraulic resistance.

The stiffness of the sleeve spring is higher than the stiffness of the piston spring. The inner diameter of the channel in the saddle is made smaller than the inner diameter of the sleeve.

Under the influence of the pressure drop, at the calculated value, the piston moves, and the bypass valve remains in its place. When the pressure inside the pulsator rises when it is exceeded enough to compress the spring, the valve breaks away from the seat and the fluid with water hammer enters through the bypass windows into the cavity with pressure pulsation. After pressure drop, the piston with the valve under the influence of compressed springs returns to its original position, with the liquid supply shut off.

The disadvantages of the design include:

- the device has sufficient complexity and can work with a sufficiently large pressure drop.

In this case, the device is structurally limited in diameter, since it is used in a well.

The stiffness of the springs is determined from the ability to keep the valve closed, with the perception of a high pressure drop, of the order of ΔP = 2 ÷ 3 MPa or more.

The use of the device is also limited by the temperature in the well, which limits its use at high temperatures, for example, when using thermal methods, where the temperature can reach T = 200 ° C or more. For example, the development of the Yaregskoye field by the thermal mine method is known (see Overview "Features of thermal exposure under conditions of fractured-porous reservoirs containing highly viscous oil" / AM Ruzin, L.Sh. Ibragimov and others. Series "Oilfield business. VNIIOENG. Issue No. 10 (99). Moscow, 1985).

In this paper, it is noted that oil is extracted from a mine, into which pipes come from horizontal, at a small angle, wells. The formation is heated by supplying steam from the surface through vertical wells. At the same time, the temperature in the mine can reach T = ÷ 50 ° C, which is dangerous for maintenance personnel.

In horizontal wells, oil and gas-vapor mixture periodically accumulate. As the oil accumulates, it is drained by opening the valve, and close at the moment the steam breakthrough begins.

The pressure drop at which the whole process occurs does not exceed ΔP = 0.1 ÷ 0.15 MPa.

With such a small pressure drop and the presence of a vapor-gas mixture, the device according to this patent cannot work.

A known design of a hydrodynamic pulsator (see RF patent No. 2446269).

The hydrodynamic pulsator consists of a housing with bypass windows equipped with a bottom cover. In the axial channel of the housing, in the upper part there is a saddle, to which the end valve with a sleeve equipped with an inner annular protrusion at the lower end is spring loaded.

An annular piston is installed inside the axial channel of the valve, which is pressed against the seat on the saddle by a spring resting on the inner annular protrusion of the sleeve. The annular piston is equipped with a hollow rod, in the axial channel of which the throttle is contained. The bottom cover is equipped with a needle entering the axial channel of the throttle. The internal cavity of the axial channel of the housing is constantly hydraulically connected bypass, or otherwise a damping channel, in the body of the housing, with the cavity of the outlet pipe. The seat travel in the axial channel of the housing is limited by a stop.

The needle contains on the outer side longitudinal grooves that play the role of throttling channels, the total cross-sectional area of which is determined based on the flow rate of the well and obtaining the necessary pulsation frequency.

The device assembly is installed in the axial channel of the outlet pipe.

With a sharp opening of the end valve, there is a sharp increase in the flow rate of the reservoir fluid and the flow velocity in the axial channel of the pipe tubing string. The perturbation wave contributes to the creation of a barrier to the movement of paraffin molecules to the wall of the pipes of the lift column, with their absorption.

The disadvantages of the design include:

- the need to have a sufficiently large diameter of the axial channel of the hollow rod, in combination with a large diameter of the mechanical valve, you need to have a spring of large axial force, which is quite difficult to obtain, especially with limited diametrical dimensions of the structure;

- based on this, we can conclude about the low reliability of the design;

- the complexity of tuning to the technological mode of operation of the well.

The known design of the shutoff valve (see RF patent No. 2533394, published November 20, 2014), adopted by the authors as a prototype.

The invention relates to the oil and gas industry and is used in wells, as part of an elevator pipe string. The shut-off valve consists of a detachable body, with a seat in the axial channel. Below is a hollow plunger with an annular protrusion, rigidly connected through a hollow tube to a poppet valve. The hollow plunger rests on a spring with a nut. An emphasis is made in the axial channel of the hollow plunger, on which a sleeve is supported, provided with radial holes alternating with axial holes that connect the cavity under the hollow plunger with the cavity under the saddle. In the axial channel of the sleeve there is a hollow tube equipped with a poppet valve. A hollow plunger with an annular protrusion forms an annular chamber with a detachable body hydraulically connected through a radial hole in the hollow plunger and radial holes in the sleeve, with its axial channel and the hollow tube channel. The sleeve is provided with a bottom, in which a central hole is made and a bypass valve is installed, blocking the bypass holes with its plate, connecting the axial channel of the sleeve with the axial channel of the split housing above the hollow plunger, with the bypass valve open, limited by the snap ring upward. A thrust sleeve is installed in the axial channel of the detachable body, with the possibility of forming a movable connection with the upper end of the hollow plunger. The cavity above the annular protrusion of the hollow plunger, through the hole in its body communicates with the axial channel above the sleeve. The device is installed as part of a pipe string.

The poppet valve is pressed by a spring force against a seat located in the axial channel of the split housing. The pressure of the working fluid in the pipe string through the axial channel of the hollow tube, the radial holes in the body of the sleeve and the radial hole in the body of the hollow plunger acts on the annular protrusion from below, which ensures the contact of the poppet valve with the surface of the seat. The same pressure is perceived by the cross-sectional area of the same poppet valve.

The cross-sectional area of the annular protrusion is taken less than the cross-sectional area of the poppet valve, which ensures that it is pressed against the seat by a spring. If the overpressure above the poppet valve exceeds the hydraulic pressure from the column of the working fluid, the poppet valve comes off the seat, with the formation of a hydraulic connection between the axial channel of the pipes and the axial channel of the split housing above the sleeve. The working fluid through the axial holes in the sleeve passes to the bottom of the well. A hollow plunger, when the poppet valve is separated from the seat, under the influence of excessive pressure, moves to the stop in the ledge.

After the supply of the working fluid is stopped, the hollow plunger, together with the sleeve and the poppet valve, rises upward in the axial channel of the split housing with the poppet valve landing on the seat. This eliminates the ingress of working fluid into the reservoir, which is important for the preservation of gas wells in underground gas storages.

The disadvantages of the design and operation of the device.

In the case of equipping oil wells, the production of which is carried out using thermal methods, the device cannot work.

In this case, the pressure of the reservoir fluid may be insufficient to open the poppet valve and compress the spring, which also determines the failure of the device.

When installing the device in the composition of the pipes in the well, it is impossible to reconfigure to a new mode without dismantling from the place of use.

To open the poppet valve with a small pressure drop, it is impossible to create sufficient axial force without the use of an additional power unit.

Limitations on the diametral dimensions of the device imposed by the well design affects the throughput of the device due to the low throughput of the reservoir fluid through the axial holes in the sleeve.

The valve design is not designed to operate at high temperatures in the reservoir fluid and cannot respond to changes in this temperature.

The technical result that can be obtained by implementing the invention is as follows:

- the ability to ensure the operation of the valve with a small pressure drop during the alternate action of two media on it - formation fluid and gas-vapor mixture;

- the ability to close the valve when exposed to gas-vapor mixture with isolation of the cavity of the mine from a horizontal well;

- the ability to open the reservoir fluid valve for supply to the mine, which has a lower temperature than the vapor-gas mixture;

- the ability to purge the internal cavity of the valve from mechanical particles, to clean the seating surface of the seat and mechanical valve, from an external source of low-pressure inert gas.

The technical result is achieved in that the device consists of a detachable body with a nipple on the outside, with a seat in the axial channel, a spring-loaded poppet valve with a pusher inside the sleeve, equipped with ribs on the outside and a bottom in the middle part, above which the container is placed, with the formation of an annular the gap hydraulically connected bypass holes, with the axial channel of the split housing. The hollow plunger faces the bottom with the end part, in which a central hole with a reciprocal bore is made and a pusher with an annular protrusion is inserted, the upper end skipped inside the container, with the lower end located in the axial channel of the hollow plunger and fixed with a nut. The lower end of the hollow plunger is equipped with a poppet valve. A nut with connecting ribs and a washer is installed in the axial channel of the saddle at the upper end, on which the spring rests. The container is filled with a thermally expanding substance, for example, ceresin with copper filings, and the saddle is made of a heat-resistant material, for example, fluoroplastic.

The shut-off valve is shown in the figures, where:

- in FIG. 1 is a general sectional view of the structure in the open position;

- in FIG. 2 - sectional design of the device in the closed position;

- in FIG. 3 - shows the installation diagram of the shut-off valve in the shaft at the output end of the horizontal well pipe.

The shut-off valve consists of a detachable housing 1, the axial channel 2 of which is blocked from above by an adapter 3.

A saddle 4 with a protective washer 5 is installed at the lower end of the detachable housing 1, which are pressed from the bottom by a screwdriver 6, in the middle of which a nut 7 with a washer 8 is installed, connected with connecting ribs 9.

Over the saddle 4 in the axial channel 2 of the detachable body 1, a sleeve 10 with a bottom 11 is installed, under which a hollow plunger 12 with a poppet valve 13 is placed, in the axial channel 2, pressed against the bottom 11 by a spring 14. The sleeve 10 has a bore 15 in the upper part, which holds the container 16, with the formation of an annular gap 17, hydraulically connected through the bypass holes 18, with the axial channel 2 of the detachable housing 1. Inside the container 16 there is a reflector 19 and a pusher 20 passed through the bottom 11 and the body of the hollow plunger 12 of the poppet valve 13. atel 20 is provided with an annular shoulder 21 within the bore 22 in the mating end face of the hollow plunger 12 and fixed with nuts 23. Inside the container 16 is filled with intumescent substance, isolated from the external environment. The container 16 is fixed in the axial channel of the sleeve 10 by a nut 24. In the hollow plunger 12, in its end part facing the bottom 11, a drainage hole 25 is made. The sleeve 10 is provided with ribs 26, which enter the bore 27, at the junction of the parts of the split housing 1 .

The annular gap between the sleeve 10 and the body of the hollow plunger 12 is closed by a sealing ring 28. The adapter 3 is equipped with a nipple 29, for connecting the axial channel 2 of the detachable housing 1 with a pneumatic pipe, for supplying inert gas and blowing off mechanical impurities when they accumulate inside.

The operation of the device.

The shut-off valve assembly is mounted on the outlet end of the horizontal well pipe in the open position.

When opening the gap between the poppet valve 13 and the seat 4, the formation fluid from the axial channel 2 of the device flows through the annular gap between the poppet valve 13 and the seat 4, outside the device, flowing around the connecting ribs 9.

The reservoir fluid is heated to a temperature of the order of T = 75 ÷ 80 ° C, which leads to heating of the structural elements.

The accumulated portion of the reservoir fluid expires due to the presence of a pressure drop from the liquid column and the gas mixture. After the formation fluid is drained, a vapor-gas mixture breaks out, having a higher temperature, of the order of T = 100 ÷ 110 ° C, which leads to heating of the container 16 and the entire structure, including the thermally expanding substance inside the container 16. The expansion of this substance leads to an increase pressure, which affects the cross-sectional area of the pusher 20, with its movement down, together with the hollow plunger 12. The hollow plunger 12 overcomes the resistance of the spring 14 and the poppet valve 13 sits on the seat 4, with the isolation of the axial channel 2 from the external medium s and stopping supplying the gas-vapor mixture in the tunnel. Then there is an accumulation of formation fluid in the well, with a decrease in the temperature of the parts of the device.

When cooling the formation fluid in the axial channel 2 of the device, due to convection interaction with the environment, there is also a decrease in the temperature of the thermally expanding substance inside the container 16.

By the force of the compressed spring 14, the hollow plunger 12 with the poppet valve 13 moves upward relative to the sleeve 10, with the opening of the annular gap between the seat 4 and the poppet valve 13.

This is due to a decrease in the volume of thermally expanding substances inside the container 16.

Due to the presence of the drainage hole 25 in the end part of the hollow plunger 12, the o-ring 28 is in the neutral position when the shut-off valve is open. In the closed position, the sealing ring 28 isolates the annular gap and eliminates the flow of formation fluid from the axial channel 2 of the detachable housing 1 for ejection into the adit.

A mixture of ceresin powder and copper granules is used as a thermal expansion agent.

During the operation of the device, mechanical particles may get inside the flow of formation fluid, which may prevent the end-face valve 13 from being sealed tightly on the seat 4. For this purpose, the device is equipped with a nipple 29, which connects to the inert gas pipeline, from which mechanical removal may be possible particles from the device, which ensures the reliability of its operation.

Claims (1)

The shut-off valve, consisting of a detachable body, with a seat in the axial channel, a spring-loaded poppet valve, a sleeve, a hollow plunger, an o-ring, characterized in that the detachable body is equipped with a nipple, a sleeve with ribs on the outside and a bottom in the middle part, a container with a reflector inside, installed above the bottom in the axial channel of the sleeve, with the formation of an annular gap hydraulically connected bypass holes with the axial channel of the detachable body and preloaded by a nut, a hollow plunger provided a drainage hole and a Central hole with a reciprocal bore, a pusher with an annular protrusion mounted in the reciprocal bore, the upper end of which is passed into the container, with the lower end in the axial channel of the hollow plunger with fixing nuts, and the lower end of the hollow plunger is equipped with a poppet valve, in the axial a nut is installed in the seat channel, connecting ribs and a washer at the upper end, with the possibility of spring support on it, the annular gap between the sleeve and the hollow plunger is closed by a sealing ring tsom and the seat made of a heat-resistant material and is provided with a side plate, wherein the container is filled with intumescent substance is preloaded nut and connected to the sleeve.

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