RU2348784C2 - Valve device of downhole drilling motor - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: present invention pertains to drilling techniques and can be used in drilling oil and gas wells using downhole drilling motors. The device has a hallow case with side openings, a bushing fitted inside the case, with a seat, radial overflow valves, a centre channel, facing a slide valve, spring loaded against the stop, fitted with provision for axial displacement and with a cowling, packing rings for covering the centre channel and a nut, limiting movement of the slide valve, and a bushing. The device has an upper adapter and a rubber seal, on whose outer surface there is a groove in which a baffle plate is fit. At one end of the seal, there is conical ring-shaped ledge, which, together with the baffle plate, is pressed to the slide valve and the hollow housing by an adjustment ring and a bearing disc, with the help of the threaded joint of the upper adapter with the hollow case. The other end of the seal freely lies inside the bushing with an annular gap in the zone of radial overflow channels and the seat of the bushing. The slide valve is fitted inside the bushing, in the bottom part, which is lower than the step made on its outer surface. There are overflow channels coming out to the annular gap, formed by the bushing, fitted on the outer step of the bush sleeve, and the bottom part of the bush sleeve.

EFFECT: reduced hydraulic resistance to the flow of drilling fluid, elimination of intense abrasion and fast wearing of components, increased air-tightness of the valve device, provision for long storage periods in working condition and increased reliability, durability and cost effectiveness of the device.

4 cl, 2 dwg

Description

The invention relates to drilling equipment and can be used when drilling oil and gas wells as a part of downhole motors for filling and emptying the drill string with flushing fluid, and to prevent sludge from downhole motors and to prevent accidental discharge from the reservoir.

A valve device is known (US Patent No. 4,298,077, priority date 1981.11.03, patent holder: Smith International Inc, Newport Beach, Calif). The valve device comprises a hollow body with radial bypass channels, a spring-loaded plunger with a central inlet and outlet flow channel formed together with the hollow body, ring seals.

A disadvantage of the known valve device of the downhole motor is that the plunger, undergoing axial translational and partially reverse-rotational movement in the medium of the flushing fluid, is subjected to hydroabrasive wear, which reduces the efficiency of the valve device.

The well-known “Overflow valve of a volumetric downhole motor” (RU, patent No. 34196, priority date 2002,12,06, patent holder of OJSC NPO Drilling equipment). The device comprises a housing with holes, bushings located inside the housing, and a spring-loaded locking element having radial holes, seals are made on the ends of the piston.

The disadvantage of this analogue is that the rubber seals are washed with flushing fluid and, periodically moving, cross the sharp edges of the radial channels. This leads to the rapid destruction of the seals, the violation of the tightness of the valve device and early repair of the device.

It is known "Valve device of the drill string" (RU, patent No. 2035581, priority date 1992.12.03, patent holder Waldman I.Ya. and others). The valve assembly of the drill string is provided with a seat fixed in the housing and located under the elastic sleeve. The filled valve is made spring-loaded poppet and mounted in the seat, in which the output channels are made.

A disadvantage of the known analogue is that it has cavities for the possible accumulation of sludge from the annulus, which prevents the valve disc from moving and renders the valve device unusable.

Also a disadvantage of the known analogue can be attributed to insufficient tightness of the housing, while leaking flushing fluid erodes the details of the valve device.

These disadvantages completely exclude the possibility of using the well-known analog in the composition of downhole motors.

Known "Valve device downhole motor" (RU, patent No. 2224866, priority date 2002.07.29, patent holder G. Schelkonogov). The device comprises a hollow body with radial bypass channels, a sleeve with a saddle and radial bypasses installed inside the hollow body, a spring-loaded plunger with a central inlet flow channel and an output flow channel with radial channels formed together with the hollow body, ring seals. This valve device is the closest analogue in technical essence and the achieved result of the claimed invention and therefore is taken as a prototype of the claimed invention.

The prototype partially eliminated some of the disadvantages of known valve devices. A significant disadvantage of the prototype is that the sleeve with radial transfer channels is movable and, therefore, during operation, the sharp edges of the radial transfer and flow channels move along the rubber sealing rings. This leads to local destruction (cutting) of the sealing edges of the sealing rings, violation of the seal, to the subsequent erosion of parts and premature failure of the entire known valve device of the downhole motor.

A disadvantage of the known valve device of the downhole motor is that the hollow body is not protected from erosion. A jet of flushing liquid under excessive pressure at high speed from the flow channels, made in the form of slits, hits the hollow body. As a result, the hollow body undergoes local intensive hydroabrasive wear, accelerated abrasion and early referral for repair.

These and other disadvantages of the known valve device of the downhole motor increase the time, labor and funds for operation, reduce its reliability and durability, hinder the possibility of their widespread use in screw bottomhole motors, and reduce the economic efficiency of screw bottomhole motors.

The objective of the claimed invention is to increase the reliability of the valve device of a downhole motor by ensuring tightness and reducing wear of parts and by reducing hydraulic resistance to the flow of flushing fluid.

The problem in the inventive valve device of a downhole motor is solved by a known valve device of a downhole motor comprising a hollow body with side holes installed inside the hollow body of a sleeve made with a saddle, radial channels and a central channel facing the spring-loaded spool installed with the possibility of axial movement and equipped with a fairing and piston rings to block the Central channel, according to the invention valve devices equipped with a bushing, sub and rubber cuff, having an annular groove on the outer surface into which the bump is installed, the cuff has an annular protrusion at one end that is rigidly connected to the sleeve by pressing the adjusting ring and thrust disc by means of a threaded connection of the sub with a hollow body and the other end of the cuff is freely located inside the sleeve with an annular gap in the area of the radial channels and the seat of the sleeve, while the spool is installed inside the sleeve, on the outer surface of which a step has been made, and a baffle sleeve with a gap and with the possibility of interacting with the radial channels of the sleeve is installed on the step, while an outer annular groove is made in the sleeve at the interface with the side holes of the hollow body, and the radial channels are made in the form of local transverse slots, the diameter and the cross-sectional area of which exceed, respectively, the diameter and the square of the cross-sectional area of the side holes of the hollow body, and the square of the cross-sectional area in the annular gap between the sleeve and the rubber oic cuff made equal to or less than the flow area of the side openings of the hollow body, wherein the rubber cuff in seat area made diffuser.

To clarify the essence of the invention, the drawings are presented:

Figure 1 shows the valve device of a downhole screw motor - general view, longitudinal section.

Figure 2 shows the valve device of a downhole screw motor - a cross section through radial channels.

The downhole screw motor valve device comprises a hollow body 1 with side openings 2 mounted inside a hollow body 1, a sleeve 3 with a seat 4, with radial transfer channels 5 and radial flow channels 6 and a flow seat 7, mounted in the sleeve 3 with a spring-loaded spring loaded axial movement 8 to the stop 9 spool 10 with a fairing 11 in the upper part of the spool 10 and with piston rings 12 extending to the flowing seat 7 to overlap the central flow channel 13 formed in the sleeve 3. the construction of the downhole screw motor is equipped with a rubber sleeve 15 fixed to one upper end 14 in the hollow body 1 with a bump 16 installed in the middle, installed by the other free end 17 in the sleeve 3 in the zone “a” of the radial transfer channels 5 and in the zone “b” of the saddle 4 with a ring the gap 18 between the sleeve 3 and the rubber cuff 15 with the chipper 16, and in the sleeve 3 below the saddle 4 is made an inner step 19, while in the hollow body 1 is installed a fender sleeve 20, and the step 21 is made on the sleeve 3 from the outside, and between the fender sleeve 20 and gil An annular gap 22 is made 3, and an annular seal 23 is made between the radial transfer channels 5 and the outer step 21 of the sleeve 3.

In the proposed valve device of the downhole motor in the sleeve 3 at the interface with the side holes 2 of the hollow body 1, an outer annular groove 24 is made, and the radial transfer channels 5 are made in the form of local transverse slots, the diameter and area of the passage section of which exceed the diameter and area, respectively the bore of the side holes 2 of the hollow body 1.

In the proposed valve device of the downhole motor, the cross-sectional area in the annular gap 18 between the sleeve 3 and the free end 17 of the rubber cuff 15 with the bump 16 is made equal to or less than the area of the passage section of the side holes 2 of the hollow body 1. In the proposed valve device of the downhole motor on a free the end of the rubber cuff 15 in the zone "b" of the seat 4 of the sleeve 3 is made diffuser 25 (expansion), and on the other, the upper end 14 of the rubber cuff 15 is made expanding to the periphery of the conical ring evy ledge 26, having the shape of a "dovetail" for interaction with the hollow body 1, the chipper 16 and the thrust disc 27 covered by a rubber sleeve 15.

To fix the rubber sleeve 15 and seal it in the hollow body 1, use the thrust disk 27, the upper sub 28 and the adjusting ring 29, pressing the conical ring protrusion 26 of the rubber sleeve 15 with the bump 16 to the sleeve 3 and to the hollow body 1. The conical ring protrusion 26 is made expanding to the periphery in the form of a dovetail.

On the hollow body 1, an external locking thread 30 is cut from below, and an internal locking thread 31 is made in the upper sub 28. The movement of the spool 10 in the sleeve 3 is limited by a nut 32 with axial holes 33.

The valve device of a downhole motor with an internal locking thread 31 of the upper sub 28 is connected to the drill pipes, and the external locking thread 30 of the hollow body 1 is connected to the downhole motor (the drill pipes and the downhole motor are not shown in the drawing).

The proposed valve device of a downhole screw motor operates as follows.

When the valve device of the downhole motor is lowered into the well (as part of the drill string), the flushing fluid displaced from the well, under slight excess pressure, enters the side openings 2 of the hollow body 1, is partially cleaned of large pieces of sludge, spreads around the entire perimeter of the outer annular groove 24 , washes radial transfer channels 5 in the zone "a" of the sleeve 3, passes through them and hits the chipper 16, which is sent to the annular gap 18. Washing from the outside the free end 17 in the saddle zone 4, the rubber sleeve 15, under excess (small) pressure washing fluid expands partially annular gap 18, and thereby creates conditions for reducing the inflow of the hydraulic resistance.

Leaving from the annular gap 18, the flushing fluid with the inner stage 19 and the cowling 11 is directed inside the valve device and the drill pipe until a pressure differential is applied, and fills the internal cavity of the valve device (its upper part) and drill pipes (not shown). The spool 10 with its lower part covers the radial flow channels 6 in the sleeve 3 and is held by a compressed spring 8 in the upper position pressed against the stop 9. The piston rings 12, interacting with the flowing seat 7 of the sleeve 3 and with the spool 10, prevent leakage of flushing fluid to the downhole motor (not shown).

When the drilling pumps are turned on, the flushing fluid under excessive pressure enters the upper sub 28 of the valve device, washes the control ring 29, the thrust disc 27 and the rubber sleeve 15 from the inside. Due to the small cross-section, the speed of the flushing fluid in the annular gap 18 increases sharply, the pressure drops . Excessive pressure flushing fluid, acting on the rubber cuff 15 from the inside, stretches it and leads to the expansion of the free end 17 in the zone "b" of the seat 4; first at the lower end in the place of greatest expansion of the diffuser 25, then the entire free end 17 of the rubber sleeve 15 in the zone "b". This leads to a complete overlap of the annular gap 18. With a further increase in the pressure drop, the rubber cuff 15 wedges in the annular gap 18 between the sleeve 3 and the chipper 16 and completely prevents possible leakage of flushing fluid.

Under overpressure, the flushing fluid enters the central flow channel 13, acts on the fairing 11 and, compressing the spring 8, moves the spool 10 down to the stop in the nut 32. The flushing fluid located under the spool 10 through the axial holes 33 in the nut 32 flows out of the closed volume.

The flushing fluid by the cowling 11 is directed with minimal hydraulic resistance into the radial flow channels 6 in the sleeve 3, into the annular gap 22, formed by the baffle sleeve 20 and the lower part (below the outer step 21) of the sleeve 3, and then to the exit of the valve device to the downhole screw motor .

When downhole mechanisms are operating in the valve device of a downhole motor, flushing fluid, flowing under excess pressure with low hydraulic resistance through the central part into the annular gap 22, simultaneously acts on the free end 17 of the rubber sleeve 15 in the zone “b” of the seat 4 of the sleeve 3 and, aiming expand the diffuser 25, presses and holds the free end 17 of the rubber sleeve 15 tightly pressed to the seat 4 of the sleeve 3, thereby reliably sealing the valve device of the downhole motor i.

Thus, in the inventive valve device of the downhole motor in the zone “b” of the seat 4 of the sleeve 3, the necessary and sufficient overpressure is maintained, and there is a real possibility of reducing the unproductive flow rate of flushing fluid and increasing the productivity of the drilling tool (downhole motor).

When the supply of flushing fluid to the valve device of the downhole motor is stopped (when the mud pumps are turned off), the spool 10, under the action of the spring 8, rises up to the stop 9, closes the central flow channel 13, and the piston rings 12 seal the flow channel, interacting with the sleeve 3 along the flow seat 7. The spool 10 closes the radial flow channels 6, and the flushing fluid through the axial holes 33 in the nut 32 from the bottom fills the closed cavity under the spool 10. The pressure of the flushing fluid inside the valve annogo apparatus and outside of it is aligned (or the pressure difference becomes small). Under the action of elastic forces, the rubber cuff 15 is compressed and, returning to its original position, opens an annular gap 18 for free flow of flushing fluid in both directions.

When lifting the valve device of the downhole motor from the well, the flushing fluid from the drill string is freely drained through the opened hydraulic channel into the annulus. When lifting the valve device of the downhole motor from the well, flushing fluid under excess pressure associated with a change in the height of its level inside the drill string and the level in the well flows into the upper part of the valve device. The cowling 11 and the inner step 19 of the sleeve 3, it is directed into the open annular gap 18. Washing the inner and outer sides of the free end 17 of the rubber cuff 15 with different speeds, the flushing fluid acts on the inner and outer sides with different forces.

Upon reaching a certain pressure drop and its subsequent increase at the free end 17 of the rubber sleeve 15, the pressure sleeve can stretch, expanding the diffuser 25, and increase in diameter, completely overlap the annular gap 18 and press firmly against the sleeve 3 in the zone “b” of the seat 4. This pressure drop is created by the mud pumps when flushing fluid is supplied under overpressure to the downhole mechanisms (screw downhole motor).

Thus, the rubber sleeve 15 at its free end 17 reacts more sensitively to small changes in the pressure drop inside and outside the valve device of the downhole motor and, after reaching a certain pressure drop, blocks the hydraulic transfer channel by expanding the free end 17 of the rubber sleeve 15 and pressing it against saddle 4 sleeves 3 forces increasing pressure drop.

As a result of a significant pressure drop, the free end 17 of the rubber sleeve 15 is held in an expanded state and tightly pressed against the sleeve 4 of the sleeve 3. In addition, the partially deformed free end 17 of the rubber sleeve 15 wedges the annular gap 18 between the sleeve 3 and the chipper 16, increasing the sealing of the valve device downhole screw motor.

In the inventive valve device of a downhole motor, the outflowing fluid of the washing fluid is formed with a low hydraulic resistance, thereby reducing wear, abrasion and preventing erosion and premature destruction of parts of the valve device.

With a significant reverse pressure drop, for example, when ejected from the reservoir, the washing fluid under excessive pressure acts on the outer stage 21 of the sleeve 3, is reflected from it, and the washing fluid does not move upward. Increased pressure through the axial holes 33 in the nut 32, the flushing fluid acts on the spool 10 and presses it more firmly against the stop 9. The piston rings 12, interacting with the spool 10 and the flow seat 7 of the sleeve 3, prevent leakage and leakage of flushing fluid into the upper part of the screw valve device downhole motor. The central flow channel 13 is blocked by the spool 10 and prevents the washing fluid from moving together with the possible slurry from the well up.

Due to the design of the conical annular protrusion 26 when tightening the fastening thread of the upper sub 28 with the adjusting ring 29, the possibility of reliable sealing and fastening of the parts in the hollow body 1 is achieved, and the necessary mutual arrangement of the rubber sleeve 15, sleeve 3 and fairing 11 in the hollow body 1 is possible. the locking thread 30 is used to connect to a downhole screw motor, and the internal locking thread 31 is used to drill pipe.

Due to the fact that the valve device is equipped with a rubber sleeve 15 fixed to one upper end 14 in the hollow body 1 with a baffle 16 in the middle, installed by the free end 17 in the sleeve 3 in the zone “a” of the radial transfer channels 5 and the saddle 4 with an annular gap 18, the possibility of the harmful effects of the sharp edges of the radial transfer channels 5 of the sleeve 3 and the side holes 2 of the hollow body 1 on the rubber sleeve 15 is eliminated, the central part of the valve device for its more efficient use is released - for the flushing duct full-time fluid. This allows you to reduce the hydraulic resistance of the valve device, to increase reliability and durability.

In connection with the location of the fairing 11 of the spool 10 in the zone “b” of the seat 4 of the sleeve 3, together with the internal stage 19 made in the sleeve 3 below the seat 4, the hydraulic resistance decreases and the loss of flushing fluid decreases when it flows from the internal cavity of the valve device into the annulus and back. This increases the efficiency of the valve device, keeps it in working condition for a longer period.

The fender sleeve 20, mounted in the hollow body 1, protects the hollow body 1 from the harmful effects of a jet of flushing fluid moving at a high speed. This keeps the case for a longer period in working condition. And in cooperation with the fairing 11, with the radial flow channels 6, the sleeve 3 and the outer step 21 made on the sleeve 3 and, together with the annular seal 23 made, the baffle 20 reflects, forms and directs the outflowing stream of washing liquid with the least hydraulic losses in downhole screw motor. At the same time, the efficiency of the valve device and the downhole motor increases, the reliability and durability of the valve device increase, and production costs for drilling oil and gas wells are reduced.

The outer annular groove 24, made on the sleeve 3, and the radial transfer channels 5, made in the form of local transverse slots in combination with the side holes 2 of the hollow body 1, prevent the passage of large pieces of cuttings from the annulus into the annular gap 18. This prevents sludging and reduces wear on parts.

Due to the fact that the diameter and the area of the passage section of the radial transfer channels in the form of local transverse slots respectively exceed the diameter and the area of the passage section of the side holes 2 of the hollow body, the passage section increases, the hydraulic resistance to the fluid flow decreases, and large pieces of drilled holes are not allowed rocks in the annular gap 18.

Due to the fact that the passage area in the annular gap 18 is made equal to or less than the passage area of the side holes 2 of the hollow body 1, the sensitivity of the valve device to changes in pressure difference is increased, a clearer and faster response is achieved, and unproductive flow rate and loss of flushing fluid are reduced .

The diffuser 25 increases the sensitivity of the rubber cuff 15 and overlaps the annular gap 18, starting at the lower end of the rubber cuff 15, in the place of greatest expansion.

Thus, the implementation of the distinguishing features of the proposed valve device of the downhole motor in combination with the known ones creates the opportunity to eliminate the disadvantages inherent in the known valve device of the downhole motor and to achieve a positive technical result:

- reduction of hydraulic resistance to the flow of washing fluid due to a more rational and efficient use of the cross-sectional area;

- eliminating the possibility of intensive abrasion and accelerated wear of parts by eliminating the sliding of parts with sharp edges along the rubber seals and preventing the possibility of leakage and subsequent erosion of parts;

- increase the sealing of the valve device due to the tight pressing of the free end of the rubber cuff to the seat of the sleeve;

- maintaining for a longer period in working condition and ultimately increasing the reliability, durability and economic efficiency of the proposed valve device of a downhole screw motor.

Claims (4)

1. The valve device of a downhole screw motor, comprising a hollow body with side openings, a sleeve installed inside the hollow body, made with a seat, radial transfer channels, a central channel facing the spool, which is spring-loaded as far as it will go, axially mounted and equipped with a fairing and piston rings for blocking the central channel and a nut restricting the movement of the spool, a baffle sleeve, characterized in that the valve device is equipped with an upper sub m and a rubber cuff having a groove on the outer surface into which the chipper is installed, the cuff having a tapered annular protrusion at one end, which, together with the chipper, is pressed against the sleeve and the hollow body by the adjusting ring and the thrust disc by means of a threaded connection of the upper sub with the hollow the casing, and the other end of the cuff is freely located inside the sleeve with an annular gap in the zone of the radial transfer channels and the seat of the sleeve, the spool being installed inside the sleeve, in the lower part of which is lower than the step made on its outer surface, flow channels are made, extending into an annular gap formed by a fender sleeve mounted on the outer step of the sleeve and the lower part of the sleeve. 2. The valve device according to claim 1, characterized in that an outer annular groove is made in the sleeve at the interface with the side openings of the hollow body, and the radial transfer channels are made in the form of local transverse slots, the diameter and passage area of which exceed respectively the diameter and the cross-sectional area of the side openings of the hollow body. 3. The valve device according to claim 1 or 2, characterized in that the area of the bore in the annular gap between the sleeve and the rubber sleeve is made equal to or less than the area of the bore of the side holes of the hollow body. 4. The valve device according to claim 1, characterized in that a diffuser is made on the rubber cuff in the area of the seat.

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