RU1806256C - Device for slurry protecting and greasing of cone drill bit - Google Patents

Abstract

Usage: drilling wells in quarries. SUMMARY OF THE INVENTION: the device comprises a valve in the form of a hollow cylinder with a cover and a spool. The valve is made with through radial holes. A solid baffle divides the valve cavity into two parts. At the top is a spool. The limiter of its movement is made in the form of a rod. The spool is installed with the possibility of blocking its radial holes with the inner surface of the valve. 1 ill.

Description

FIELD OF THE INVENTION This invention relates to drilling wells in quarries using roller cone bits, cleaning the bottom with compressed air or an air-water mixture, and can be used for drilling waterlogged wells.

The aim of the invention is to improve the performance of the device and increase its durability.

This goal is achieved in that in the device for sludge protection and lubrication of the bearings of the rolling cutter bit, comprising a valve in the form of a hollow cylinder with a cover connected to the nipple of the bit, and a spool located inside the valve in the form of a hollow piston spring-loaded in the longitudinal direction, the valve is made with through radial holes located in three stages, and is equipped with a continuous partition dividing its cavity into two parts, in the upper of which there is a spool having a limiter for its movement in the form of a rod, closed lennogo valve on the lid, which is mounted in the rest position, with its radial apertures overlap the inner surface of the valve, and in the operating position - with the possibility of its radial alignment holes with medium holes valve communicating with the annular cavity of the pin chisels.

Distinctive features of the invention are the implementation of a valve with through radial holes located in three channels and equipping it with a solid partition that divides the internal cavity into two parts, in the upper of which there is a spool having a limiter for its movement in the form of a rod mounted on the lid Valve the location of the spool in the valve so that in the initial position its radial holes are overlapped by the inner surface of the valve, and in the working position with the possibility of combining its radial holes with the middle holes of the valve in communication with the annular cavity of the bit nipple.

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In the present invention, it is not the spool valve, but the valve itself, its main component - the body is made with three rows of radial holes and a solid partition dividing its cavity into two parts, in the upper of which there is a spool having a limiter of its movement in the form of a rod attached to the valve cover. Thus, in this case, a new design solution was adopted, which was used not only to distribute the flushing and blowing agent, but also to form a closed cavity with a variable volume in order to accommodate the most important valve part, the spring, in order to protect it from corrosion and abrasion wear by aggressive liquid and sand.

The location of the spool in the valve leads to the fact that when the purge is suddenly turned off and the bit is left in the well, an isolated chamber is formed above the baffle in the spring location zone with a pressure of compressed air or water-oil-air mixture in it equal to the pressure of the mixture, which preceded by shutting down the purge (usually it is 4.5-5 kg / cm2).

At the same time, the pressure in the annular cavity of the nipple of the bit and in the cavities of the cones of the cones is maintained no higher (according to the law of static equilibrium) of the value of Pop y N, kg / m, where y is the specific mass of drill cuttings or contaminated fluid in the annulus, kg / m; N - the height of the column of fluid or sludge in the well, m

If we take from 1200-1500 kg / m, a, then Rop 0200-1500) - 0 1200-15000 kg / m2 1.2-1.5 kg / cm2, i.e., 3-4 times less than in the compensation chamber where the spring is located. Therefore, in the first minutes after turning off the purge, increased pressure from the compensation chamber through possible leaks and leakage channels will create a block in the annular cavity of the nipples and in the bearings of the cones, due to the penetration of contaminated liquid and sludge into them.

The drawing shows a General schematic diagram of the proposed device for sludge protection and lubrication of bearings roller cone.

It includes a valve 1 in the form of a hollow cylinder with a cover 2 connected to a nipple 3 of a cone bit, and a spool 4 located inside the valve 1 in the form of a hollow piston with radial holes 5 in the upper part. Valve 1 is made with

through radial holes 6-8 and is equipped with a continuous partition 9, dividing its cavity into two parts, in the upper of which is located a spool 4 having a limiter for its movement in the form of a rod 10 fixed in the cover 2 of the valve 1.

In the initial position, the spool 4 is pressed against the shaft 10 by a spring 11 located in a closed chamber 12 of variable volume, while the radial holes 5 of the spool 4 are blocked by the inner surface of the valve 1, and the middle holes 7 of the valve 1 are blocked by the outer surface of the spool 4.

On top, the nipple 3 of the bit is closed by an elastic gasket 13 with the nut 14. In addition, inclined channels 16 are drilled from the annular cavity 15 of the nipple 3 to feed the flushing and purging agent into the cone of the roller cone 15, and nozzles 17 are welded into the central hole of the bit. For drilling the bit, The proposed device for sludge protection and lubrication of the bearings are connected to the drill stand of the machine.

The proposed device sludge protection and lubrication of the supports works as follows.

The flow of flushing and blowing agent from the inner cavity of the drill pipe through the radial holes 8 enters the inner cavity of the valve 1 of the bit, presses on the upper end of the spool 4 and, compressing the spring 11, shifts the spool 4 down until its radial holes 5 compatible with the middle holes 7 of the valve 1.

All this time, the force S, kg, where Pc is the pressure in the pneumatic network of the machine, kg / cm2;

S is the area of the upper end of the spool 4, cm2.

When aligning the holes 5 of the valve 4 with the holes 7 of the valve 1, the flow of the flushing and purging agent flows into the annular cavity of the nipple 15.

From here, part of it (about 30%) goes through channels 16 to the supports of cones, and the other part (70%). through holes 6 it enters the central nozzle 17 and then into the bottom hole.

During all this time, the spool 4 is held in its lowest position by the drag force of the radar. C. .. which is calculated by the expression

Mr. Y V O M o

Radar.S. -g ---- S, KG,

where, 2 - drag coefficient;

04 kg / m specific gravity of the washing-purging agent mixture;

 m / s flow rate of washing and purging agent;

d.9.81 m / s2 - acceleration of gravity;

5m S - respectively, the total cross-sectional area of the radial holes 7 and the area of the upper end of the spool 4 m2,, 785 d2.

For the case in question, 04 m, from where, 001256 m2.

If we substitute the numerical values in the formula of the drag force, we get

R.s. 1,2

2.04 (500): 2 9.81

x 0.001256 38.1 kg.

As can be seen from the calculation, the value of the drag force is quite enough to keep the spool 4 in the working position.

In the above calculation, we did not take into account the fact that the holes 5 of the spool 4 are located in the zone of intense movement of the flushing and blowing agent (speed 500 m / s) and therefore a vacuum is created in the inner chamber 12, which contributes to an increase in the active force holding the spool 4.

In the event of a sudden shutdown of the purge, the pressure of the flushing and purging agent mixture inside the drill string decreases, its flow into the annular cavity 15 is blocked. As a result, the spring 11 moves the gold; nickname 4 in its highest position until it stops in the restrictive rod 10.

Now, all the pathways for the entry of contaminated fluid and sludge from the annulus and the bottom of the well in the cavity of the chisel supports, into the annular cavity 15, and the axial hole of the central nozzle 17 and into the drill stand will be blocked.

Moreover, the highest pressure is approximately 4.5-5 atm, it will be in the inner cavity 12 of the spool 4 (in the compensation chamber), approximately half the pressure (when the height of the liquid column in the well is 10 m or more) will be in the annular cavity 15 and cavity x cones.

Therefore, at the initial moment after the purge is turned off, the mixture will leak from the compensation chamber 12 into the annular cavity 15 and into the cavity of the cone supports, creating a backwater in them that prevents the penetration of sludge.

This is a very important feature of the proposed device, because it allows to significantly increase the time of maintaining pressure seals in the sealed cavities, and, consequently, the time of guaranteed protection of the cavities from sludge. Upon resuming purging, the operation of the sludge protection device will be repeated in the described sequence.

0 It should be noted that the proposed device not only reliably seals the insulated cavities, but also separates most of the fluid and grease contained in the mixture, which goes to the center of the face, and

5 directs the separated fluid and lubricant to the cones.

This is due to the fact that the flow of the mixture entering the internal cavity of valve 1 is rotated 90 ° through the windows

0 8 enters the annular cavity 15, here the flow rotates again by 90 ° and, finally, before entering the axial hole of the central nozzle 17, another rotation occurs at a right angle.

5 At each turn, the flow is turbulized, the droplets collide and stick together, the droplets inertia increase many times and they are separated from the mixture and directed into the channels

0 16, leading into the cavity of the cones of the cones. The supply of the enriched mixture with liquid and grease additionally leads to an increase in the durability of the bits due to the lower intensity of bearing wear.

Claims (1)

5 Claims A device for sludge protection and lubrication of the bearings of a cone bit, including a valve in the form of a hollow cylinder with a cover connected to the nipple of the bit and a spool located inside the valve in the form of a hollow piston spring-loaded in the longitudinal direction, characterized in that, in order to improve performance and increase durability , 5, the valve is made with through radial holes located in three channels and is equipped with a continuous partition dividing its cavity into two parts, in the upper of which there is a spool, 0 having a limiter for its movement in the form of a rod mounted on the valve cover, the spool being installed in its initial position with the possibility of blocking its radial holes 5 by the inner surface of the valve, and in the working position, with the possibility of combining its radial holes with the middle holes of the valve in communication with the annular cavity of the bit nipple. L