RU2325508C2 - Circulating valve - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention is referred to a petroleum industry, in particular to the down hole equipment and can be used at an oil recovery, flushing, and development of holes, abandonment of hydratoparaffinic formations. It provides creation of the device with the monolithic one-piece cage, device simplification, increase of its reliability, a possibility of exact adjustment for work on selected depth depending on gravity of a fluid and a depth of immersion under the working level. Essence of invention: the device consists of the hollow body with attachment threads, a spring valve, and seal members. Thus the valve body is executed monolithic and not dismountable. The valve channel is placed on a side surface of the body and equipped on ends by blank flanges with seal members, between which the valve in the form of a plunger with the central channel and the radial through holes providing circulation of a fluid is placed. The plunger is fixed in the shut position by the calibrated springs, on one end of which the block of the shim washers is placed. It provides exact adjustment of the circulating flap on selected depth of array depending on fluid gravity and a depth of immersion under the working level. The quantity of the shim washers indispensable for adjustment of the circulating flap depending on a landing depth, fluid gravity and a depth of immersion under a working level is determined on analytical expression.

EFFECT: simplification and increasing of construction reliability; of the circulating flap working; possibility providing of exact adjustment for work on selected depth.

2 dwg

Description

The invention relates to the oil industry, in particular to downhole equipment, and can be used in oil production, flushing and development of wells, the elimination of hydrate-paraffin formations.

A known circulation valve (RU 2187623 C1, IPC E21B 34/06, 2002.08.20), consisting of a coupling with holes, a safety ring, plugs with an internal dead end channel, open from the annulus, installed in the holes of the coupling with the possibility of breaking under the action of a hammer - rods, and the holes in the coupling are threaded, the plugs are made of cast iron and screwed into the holes of the coupling, while holes are made in the safety ring, the tops of the plugs are located in the mentioned holes of the safety ring with zhnosti breaking under the action of the striker bars on the ferrule.

A disadvantage of the known circulation valve is that it is a disposable device, requires a shock rod to be discharged into the well, and can only be used during the lifting of elevator pipes to allow fluid to drain into the annulus.

Also known is a circulation valve (RU 2195553 C1, IPC E21B 49/00, 34/06, 2002.12.27) comprising a housing with radial channels, a balanced hollow piston with sealing elements and an upper conical seat, the hollow piston being provided with a spring in the upper part and at the bottom - a collet, and the body is made with an internal protrusion for fixing the collet.

A disadvantage of the known circulation valve is that for its inclusion, it is necessary to dump a steel ball into the well, in addition, the design provides for a single use of the valve in the well, for repeated preparation of the valve for operation, it must be lifted to the mouth.

Also known is a circulation valve (RU 2211915 C2, IPC E21B 34/06, 2003.09.10) containing a housing in the form of a stepped cylinder with an axial channel and a seat in the bottom, a hollow stepped spool movably housed in the housing, made with an annular piston rigidly connected to it and forming an annular chamber with the housing, channels in the housing connecting the annular chamber with the annular space, and an axial channel of the housing with the annular chamber, and it is equipped with an end valve, the housing is detachable in the form of upper and lower parts with a saddle on the upper end the bottom of the housing, the channels in the housing connecting the annular chamber with the annular space are made longitudinal in the place of the housing connector, the channel connecting the axial channel of the housing with the annular chamber is throttled, at the bottom of the detachable housing there is a narrowing with a sealing ring, the end valve covers part of the detachable housing and has the ability to interact with a saddle on the upper end of the lower part of the housing, the progress of a hollow stepped spool with a stepped annular piston ness upper end portion of the housing assembly, wherein a stepped annular piston in interaction with the sealing ring forms a seal, a stepped spool is biased, and the diameter of the stepped annular piston in the lower part than in the top.

A disadvantage of the known circulation valve is that it cannot be used in wells equipped with sucker rod pumps, there is no complete certainty that the annular step piston will work, since both its stages are in the same cylinder, the mechanical seal does not guarantee reliable sealing of the valve’s internal cavity.

The closest technical solution is the circulation valve (RU 2206714 C2, IPC E21B 34/06, 2003.06.20), containing a hollow barrel with windows and connecting threads, o-rings, a spring-loaded spool mounted on the barrel with the ability to control spring compression by moving the stop and blocking windows with their skirt in the lowermost position, a piston stepped pair formed by a spool, a barrel and sealing elements placed in the gaps between them and hydraulically connected to the barrel cavity through the hole The hole is made in the barrel, and the sealing elements are made in the form of deformable self-sealing cuffs made of elastomer, the piston pair steps are made with a variable cross-section to change the annular area of the piston stepped pair depending on the position of the spool on the barrel, and in the position of the spool corresponding to the open state of the valve , the annular area is maximum.

A disadvantage of the known valve is the design complexity caused by the need to move the spool along the composite housing with concentrically spaced surfaces, which leads to the possibility of jamming of the spool, and the possibility of spontaneous separation of the upper and lower parts of the composite housing is not excluded. There are no exact criteria for adjusting the valve for installing it at a given depth, depending on the density of the fluid and the depth of immersion under the dynamic level of the well.

The objective of the invention is to create a circulation valve with a monolithic non-separable body, which can be used in wells equipped with both USGN and ESP, simplifying the design of the valve, increasing its reliability, providing the ability to fine tune the valve to work at a given depth, depending on the density of the fluid and depth of descent under the dynamic level.

The problem is solved due to the fact that in a circulation valve containing a hollow body with connecting threads, a spring-loaded spool, sealing elements, according to the invention, the valve body is made monolithic and non-separable, and the spool channel is located on the side surface of the body and is equipped with threaded plugs with sealing ends elements between which there is a spool in the form of a plunger with a central channel and radial through holes that provide fluid circulation, the plunger it is fixed in the closed position using a calibrated spring, on one of the ends of which there is a block of adjusting washers, the number of which is determined by the formula:

where n is the number of shims for adjusting the circulation valve to the depth of its descent, fluid density and depth of descent to a dynamic level;

π is the number of "Pi";

g is the acceleration of gravity, m / s ² ;

ρ is the density of the fluid, kg / m ³ ;

d is the diameter of the plunger, m;

k - spring stiffness, N / mm;

H - the depth of the valve, m;

h - the depth of the valve descent under the dynamic level, m;

L ₀ - spring length in free state, mm;

L - valve dimension, mm;

δ is the thickness of the washer, mm.

Figure 1 shows the device of the circulation valve; figure 2 - the operation of the circulation valve.

In case 1 with channel 2 and an eccentrically located valve chamber 3, threads 4 and 5 are arranged for connection to a tubing string (not shown). The valve chamber 3 is closed on both sides by threaded plugs: blind 6 and through 7. Inside the blind threaded plug 6, a channel 8 is arranged that is hydraulically connected to the channel 2 through holes 9 and 10. Inside the channel 8, the plunger 11 moves, the channel 12 of which is hydraulically connected to the through radial holes 13. On the outer surface of the plunger 11 there is a stop 14, on which a set of adjusting washers 15 is mounted, supported by a spring 16. The groove 17 of the plunger 11 is mated to the channel 18 of the through plug 7. The end face 19 of the groove 17 is located at a distance "B" from the end 20 through tube 7, which ensures a working stroke of the plunger 11 when opening the circulating valve. All mating valve parts are insulated by sealing elements (not shown).

The circulation valve operates as follows.

If necessary, to ensure circulation from the tubing cavity to the annulus (not shown) at the wellhead, excessive pressure is created in the tubing cavity. In this case, the pressure of the liquid column from the channel 2 through the hole 9 is transmitted to the channel 8 above the plunger 11. With increasing pressure, the plunger 11 moves downward, compressing the spring 16, and sits on the end 19, restricting its course. At the same time, a hydraulic connection between the tubing cavity (through channel 2, hole 10, radial holes 13 of the plunger 11, channel 12, channel 18 of the through plug 7) and the annulus opens, and fluid flows from the tubing cavity into the annulus.

After the circulation is completed, the pressure in the tubing cavity decreases to hydrostatic, the plunger 11 returns to its original position under the action of the spring 16, while the radial holes 13 of the plunger 11 move up along the channel 8 of the blind plug 6, and the hydraulic connection between the tubing cavity and the annulus is interrupted.

Loops are repeated an unlimited number of times.

The circulation valve is set to operate depending on the depth, density of the produced fluid, and the depth of descent under the dynamic level by changing the number of shims 15, the number of which is determined by formula (1).

Using the proposed circulation valve will allow pumping of various inhibitors and paraffin solvents directly into the tubing string at working wells equipped with both UShGN and ESP, will increase the overhaul period during the operation of deep-well pumping equipment, provide a high degree of reliability, safety of work, significant savings in material resources.

In addition, the circulation valve can be used as a device to create a normalized shock repression on the formation, which is important in the process of developing wells, stimulating the flow of formation fluid and during repair and insulation works.

Claims (1)

A circulation valve comprising a hollow body with connecting threads, a spring-loaded spool, sealing elements, characterized in that the valve body is made integral and non-separable, and the spool channel is located on the side surface of the body and is equipped with threaded plugs with sealing elements at the ends, between which there is a spool in in the form of a plunger with a central channel and radial through holes for circulating fluid, the plunger is fixed in the closed position using a gauge Anna spring at one end of which is a block of shims, the number of which is determined by the formula:

where n is the number of adjusting washers for adjusting the circulation valve to the depth of its descent, the density of the fluid and the depth of descent to a dynamic level; π is the number of "Pi"; g is the acceleration of gravity, m / s; ρ - fluid density, kg / m ^3; d is the diameter of the plunger, m; k - spring stiffness, n / mm; H - the depth of the valve, m; h - the depth of the valve descent under the dynamic level, m; ₀ L - length of the spring in a free condition, mm; L - valve dimension, mm; δ is the thickness of the washer, mm.

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