RU2631123C1 - Valve unit of drilling column - Google Patents

Abstract

FIELD: drilling of soil or rock.

SUBSTANCE: invention relates to drilling equipment and is intended for hydraulic linking of inner cavity of drill column with annular space during tripping operations and for separation of said spaces in drilling conditions, including at low consumption of drilling fluid (liquid). Valve device of drill column contains elements of drill column and overflow valve, which includes a housing, valve pair consisting of a seat installed in housing, hollow piston arranged inside seat, in which there are radial holes, spring, seal. In overflow valve or elements of drill column, connected with overflow valve, there is a module to interact with hollow piston and reduce or completely cover flow passage of hollow piston at supply of drilling fluid, when inner cavity of drill column communicates with annular space. Furthermore, module can be made with variable cross-section along axis or movable, floating in drilling fluid, or in piston of overflow valve.

EFFECT: technical result consists in improvement of reliability and durability of valve unit, including at low consumption of drilling mud.

5 cl, 7 dwg

Description

The invention relates to the field of drilling equipment and is intended for hydraulic communication of the inner cavity of the drill string with the annulus during tripping operations and for separation of these spaces under drilling conditions, including at a reduced flow rate of the drilling fluid (fluid). With reduced drilling fluid consumption and in the case of flushing the well in the initial period at a low drilling fluid flow, which is sometimes required by the regulations for drilling operations, the overflow valve does not close, and the fluid enters through the radial channels in the annulus, leading to the washing of parts and the device exit system.

Known downhole valve device (Patent RU No. 2150575, IPC E21B 34/06, publ. 10.06.2000), comprising a housing with a seat and radial holes, a movable sleeve with a check valve, the outer surface of the upper part of the movable sleeve is made in the form of a truncated cone, which forms a valve pair with the housing seat, and a check valve in the form of a spool type valve with radial holes and a plug is placed in the inner cavity of the movable sleeve and is spring-loaded relative to the movable sleeve, while the movable sleeve and the check valve olneny with the possibility of moving the movable sleeve to fit on the body seat and the subsequent opening of the radial holes of the check valve when the liquid pressure. After starting up the electric pump under the valve and the movable sleeve, the pressure increases due to the initial compression load of the spring. After reaching the required pressure drop, the movable sleeve with a check valve moves up and the edge of the seat sits. A further increase in fluid pressure leads to additional compression of the spring and the opening of the radial holes of the check valve. After that, the fluid through the radial holes enters the tubing string. The tapered sleeve ensures tightness. In addition, as the pressure increases to raise the fluid in the tubing string (which is accompanied by a decrease in the fluid level in the annulus of the well), the upward axial load acting on the sleeve increases as a result of the increase in the pressure difference under the sleeve and over its conical surface under the saddle. After the electric pump stops, the pressure under the non-return valve will decrease, the spring will lower the plug to the sleeve and the radial holes will close. Under the action of the reverse fluid flow, the sleeve with the non-return valve will lower to the lower position to the tip limiter. At the same time, the sleeve and plug of the non-return valve are located below the radial openings of the housing and this ensures the maximum connectivity of the central passage section of the valve with the radial holes.

A disadvantage of the known design is the rapid wear and unstable closing of the valve during circulation of the flushing fluid when the rotor is inhibited, when the engine is sludged or if it is “stuck” in the well.

Known overflow valve company "Dyna-Drill" (see book Baldenko DF, Baldenko FD, Gnoev AN "Screw downhole motors", volume 2, M., LLC IRC Gazprom 2007 , p. 95, Fig. 3.34). The overflow valve comprises a hollow body with side openings, a piston moving in the body, a spring, a seat, an emphasis, seals and a cuff mounted on the outer surface of the piston.

During tripping operations, the pressure drop between the annulus and the internal cavity of the drill pipe is small, so the piston is held in the upper position by means of a spring. The annulus through the radial holes in the housing and the seat communicates with the internal cavity of the drill string. The drill string is filling or emptying. In the presence of circulation of the drilling fluid inside the drill string, the piston moves to the lower position under fluid pressure and closes the radial holes in the seat, separating the annulus from the inner cavity of the drill pipe. Flushing fluid enters the bottomhole mechanism.

A disadvantage of the known valve is that the cuff is mounted on the outer surface of the piston, and the piston does not have radial holes. Therefore, during tripping operations, the cuff is not in constant contact and is exposed to drilling fluid. Thus, the drilling fluid flowing from the annulus into the drill string and vice versa clogs the seating surfaces of the seat and cuff. As a result, the abrasive wear of the cuff mounted on the outer surface of the piston increases, and the erosion of the seating surfaces of the piston and seat increases.

Closest to the invention in technical essence is a valve overflow drill string (Patent RU No. 2204688, IPC E21B 21/10, publ. 05.20.2003), which is selected as a prototype. It contains a housing with a thread at the edges, a hollow piston, a saddle and a spring installed between them, the piston is placed inside the saddle and forms a stepped valve pair with two slip belts, while the perimeter of the reduced slip belt of the saddle with the bottom of the piston is 0, 33-0.77 from the perimeter of the enlarged slip zone of the seat with the upper part of the piston, and between the body and the seat there is an annular gap, which is connected with the cavity between the seat and the piston by radial holes, the upper and lower elements of the drill string us.

The disadvantage of both analogues and the prototype is their inability to block the interior of the annulus at low drilling fluid flow, and in the case of flushing the well at a low flow rate of the drilling fluid, which is sometimes required by drilling regulations or other reasons, the overflow valve does not close and the drilling the solution flows through radial channels into the annulus, leading to washing parts and the failure of the device. In addition, when flushing a well with an open valve, the wellbore located below the valve is poorly cleaned or not cleaned at all, since the fluid passes through the holes in the valve and not through the bit.

The technical task of the claimed invention is the creation of a valve device for the drill string to ensure reliable operation of it, quick and reliable separation of the internal space from the annular space when operating at low flow rate of the drilling fluid.

The technical problem is solved in that in the valve device of the drill string containing the elements of the drill string and an overflow valve, comprising a housing, a valve pair consisting of a seat installed in the housing, a hollow piston located inside the seat, in which radial holes, spring, seals are made , according to the invention, in the overflow valve or drill string elements connected to the overflow valve, a module is installed that interacts with the hollow piston and reduces or completely closes the passage e cross-section of the hollow piston when the drilling fluid is supplied, when the internal cavity of the drill string communicates with the annulus.

In addition, according to the invention, the module is made with a variable cross-section along the axis.

In addition, according to the invention, the module is movable.

In addition, according to the invention, the module is made floating in the drilling fluid.

In addition, according to the invention, the module is made in the hollow piston of the overflow valve.

In the present invention, in contrast to the prototype, the valve device of the drill string further comprises a module, with the possibility of fixing the module so that reliable operation of the valve device of the drill string when operating at low flow rate of the drilling fluid is ensured. The presence of a module that covers most of the central channel of the piston provides the occurrence of an additional excess differential pressure of the drilling fluid when it is fed into the drill string, which leads to the displacement of the piston and the overlap of the radial channels in the piston even at a reduced flow rate. The probability of valve failure and rinsing of parts is reduced (eliminated), reliability is increased, and the service life of the device is extended.

In the present invention, the module can be made with a variable cross-section along the axis, which ensures a reduction in losses at an increased flow rate. Unlike the prototype, a device is installed in the device, which can be mounted not only in the overflow valve, but also in the drill string elements - lower or upper elements, which makes it possible to use existing valves in new conditions - low fluid flow conditions. The module can be made in the drill string elements - upper or lower, for example, in particular, on the filter located in the lower element, and attached to the valve by the lower thread, or upper thread, when the module is located on the upper element, which extends the boundary and allows you to choose the option with the lowest cost, depending on specific conditions.

In the present invention, the module can be made movable, which reduces the resistance of the fluid during the descent of the drill string.

In the present invention, the module can be made floating in the drilling fluid in case of unsatisfactory emptying of the drill pipe string during lifting due to, for example, high viscosity of the fluid.

In the present invention, the module can be made in a hollow piston, which reduces the likelihood of slurry of hydraulic valve.

The implementation of the valve device of the drill string with the module provides reliable actuation (closing) with a tight separation of the inner space of the drill string with the annulus when operating at low flow rates.

In FIG. 1 shows a General view of the valve device of the drill string in longitudinal section with a module 15 mounted in the housing 3 on the thread 13 of the overflow valve, with a variable cross-section along the axis, in the transport position.

In FIG. 2 shows a General view of the valve device of the drill string in longitudinal section with a module 15 mounted in the housing 3 on the thread 13 of the overflow valve, with a variable cross-section along the axis, in the working position.

In FIG. 3 is a longitudinal view in longitudinal section of a drill string valve device with a module 15 located in the upper element 1 of the drill string in a transport position.

In FIG. 4 shows a general view in longitudinal section of the drill string valve device with a module 15 mounted in the lower element 2 of the drill string, for example on the filter 19, in the transport position.

In FIG. 5 is a longitudinal view in longitudinal section of a drill string valve device with a movable module 15 installed in the upper element of the drill string 1 in a transport position.

In FIG. 6 is a perspective view of the valve assembly of the drill string in longitudinal section with the floating module 15 in the transport position.

In FIG. 7 shows a General view of the valve device of the drill string in longitudinal section with module 15 in the hollow piston 7 of the valve.

The drill string valve device of FIG. 1 contains an upper element 1 and a lower element 2 of a drill string, an overflow valve with a casing 3 with radial holes 4, a saddle 5 with radial holes 6 installed in the casing 3, and a hollow piston 7 with an internal bore 8 and radial holes 9, which is placed inside the seat 5, a spring 10 located in the hollow channel between the hollow piston 7 and the saddle 5, seals 11, 12, 14, module 15. The module 15 is fixed to the valve body 3 over the thread 13. The central internal passage channel 8 of the hollow piston 7 connects valve A inlet with shut the dead space 17 through the radial holes 9, 6, 4 and the outlet of the valve B. The housing 3 has end upper and lower threads 16, 18. In section B, an additional local hydraulic resistance is created. The embodiment of module 15 and the location in the valve assembly of the drill string shown in FIG. 1-7 may be different. Module 15 may be installed in the top member 1 of the drill string of FIG. 3, FIG. 5, FIG. 6, which is connected to the valve body 3 by a upper thread 16. In FIG. 4 shows a valve device with a module 15 arranged on a filter 19 of a lower drill string element 2, which is connected to the housing 3 by a lower thread 18. FIG. 5 shows the design of the device with a movable module 15, which is located in the guide of the latch 20, mounted in the upper element 1 of the drill string. In FIG. 6 shows a variant similar to FIG. 5, but the module 15 is made floating in the drilling fluid, at the time of turning on the flushing of the well. In FIG. 7 shows an embodiment of a module 15 on a hollow piston 7 of an overflow valve in a transport position. In the radial holes 4 can be installed plug 21 to protect against large foreign objects.

The valve device of the drill string works as follows (Fig. 1, 2). In the transport position, as well as during tripping operations (hereinafter referred to as STR), the module 15 overlaps a large part B of the internal passage section 8 in the hollow piston 7 (Fig. 1). With a small pressure difference between the annulus 17 and the inner cavity of the drill string B, the flushing fluid flows freely through the radial holes 4 in the housing 3 and the radial holes 6 of the seat 5, the radial holes 9 of the hollow piston 7. During drilling fluid supply, even at a relatively low flow rate due to the passage section 8 blocked by the module 15 in the hollow piston 7 above the hollow piston 7, excessive pressure arises and increases sharply, which moves the hollow piston 7 to the lower position (Fig. 2). Between the module 15 and the hollow piston 7 in this position there is no longer any overlap of the internal bore 8, and the hollow piston 7 is held in the closed (working) position due to the pressure difference between the in-pipe B and the annular space 17. Now the flow rate of the drilling fluid can vary over a wide range and the valve will not open, and when operating at maximum flow, the resistance in the valve will be insignificant, since a space G has formed between the hollow piston 7 and module 15 (Fig. 2). When using existing valves and an installed module 15 in the upper element 1 of the drill string (Fig. 3), the valve device operates in the same way as described above (Fig. 1, 2). The valve with module 15 on the filter 19, in the lower element 2 (Fig. 4), for example, works similarly to the valve device of the drill string shown in Fig. 1, 2, but in the working position the pressure loss in such an arrangement will be higher than in others due to the reduced internal bore in the piston of the overflow valve, therefore, this design can successfully work only at low costs.

In the event that the internal cross section between the module 15 and the hollow piston 7 is not sufficient for the free passage of the drilling fluid to fill the drill string during descent, a movable module 15 is provided (Fig. 5), for example, in the upper element 1 of the drill string. The movable module 15 (Fig. 5) freely moves in the guide of the latch 20 to the upper position (not shown) when the drill string is lowered and freely passes fluid into the descent pipes. When the circulation is switched on, the module 15 moves down from the upper position, blocks the bore 8 in the hollow piston 7, additional pressure is created and the hollow piston 7 goes down and, as with the fixed module 15 (Fig. 1, 2), the resistance in the valve declining.

In the case of unsatisfactory release of the drill pipe string from the solution during lifting due to, for example, high viscosity of the solution, a design with a hollow module 15 floating in the solution is provided (Fig. 6). After the circulation is turned on by the flow of the drilling fluid, the module 15 will move to the lower position (Fig. 6), the cross section 8 in the hollow piston 7 will be closed, which will lead to a rapid increase in overpressure above the hollow piston 7 and it will move to the lower position. From the fact that the hollow piston 7 has moved, the overlap of the internal bore 8 in the hollow piston 7 is no more, the resistance to fluid movement in the valve falls. Depending on the specific conditions, it is possible to use from the simplest fixed-mounted (Fig. 1) and movable module 15 (Fig. 6) to the more complex with a variable cross-section along the axis (Fig. 1).

The module 15, made in the lower part of the hollow piston 7 in the form of movable petals (Fig. 7), works as follows. In the transport position during the SPO under the action of the spring 10, the hollow piston 7 is held in the upper position, and the petals of the module 15 are in the closed state, the internal passage section 8 in the hollow piston 7 is closed. When the circulation is turned on, the hollow piston 7 and the petals of the module 15 are pressurized, the petals of the module 15 are held in the closed position by the saddle 5. From the pressure drop created, the hollow piston 7 with the module 15 will move to the lower position. In this position, the petals will come out of contact with the cylindrical part of the saddle 5 and open, thereby the petals of the module 15 no longer create resistance.

Thus, the implementation of the present invention with the above distinctive features in combination with the known features allows to ensure high reliability of the valve assembly of the drill string due to the module contained in it, which creates additional excess fluid pressure when the circulation is turned on, including at a low flow rate of the drilling fluid, and after actuation (closing) of the valve device, the additional excess resistance in the device falls, which allows to increase durability and reliability of the valve device.

Claims (5)

1. The valve device of the drill string containing the elements of the drill string and the overflow valve, comprising a housing, a valve pair consisting of a seat installed in the housing, a hollow piston located inside the seat, in which there are radial holes, a spring, seals, characterized in that in the overflow valve or drill string elements connected to the overflow valve, a module is installed that interacts with the hollow piston and reduces or completely covers the bore of the hollow piston when feeding solution, when the inner cavity of the drill string communicates with the annulus. 2. The valve device of the drill string according to claim 1, characterized in that the module is made with a variable cross-section along the axis. 3. The valve device of the drill string according to claim 1, characterized in that the module is movable. 4. The valve device of the drill string according to claim 1, characterized in that the module is made floating in the drilling fluid. 5. The valve device of the drill string according to claim 1, characterized in that the module is made in the piston of the overflow valve.

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