RU2230877C2 - Boring cutter with valve assembly - Google Patents

Abstract

FIELD: boring equipment engineering.

SUBSTANCE: device has saddle immovably fixed on a shelf of nipple wall, saddle having a central aperture and water-tight coating on all sides, valve nut and reciprocal spring for it which fixes valve assembly in closed position. Boring cutter has suspended barrel with side ports, which is placed on a shelf of nipple wall under the saddle and has inner diameter, which is larger than diameter of central aperture in the saddle. Spring-loaded valve washer is made circular, solid and is located inside suspended barrel with means for full and tight covering of saddle central aperture in closed position of valve assembly.

EFFECT: higher reliability of boring cutter operation, also higher driving by cutter and mechanical speed of boring by means of providing for effective operation of valve assembly.

3 cl, 1 dwg

Description

The invention relates to the field of drilling equipment and can be used in drill bits mainly when drilling blast holes with blowing the bottom of the air.

A drill bit is known that contains a housing with purge channels and rock cutting bodies in the form of cones and a check valve consisting of a nozzle with a perforated funnel and located in the central part of the body cavity to prevent particles of drill cuttings (sludge) and water from entering cooling cones of the drill cone bits when building pipes or when the compressor stops supplying air to the well [1] (analog).

A significant drawback of this bit is the complexity of the design of the valve assembly and, as a consequence of this, a significant cost.

In addition, when the compressor stops, the borehole fluid, falling together with the sludge through the nozzle cavity into the perforated funnel, has the opportunity to enter the cavity of the in-tube space above the funnel, as well as into the narrow space between the wall of the perforated pipe and the elastic seal, reducing the already limited dimensions and the size of the holes in the cross section, making it difficult for the cooling and cleaning agent (air) to pass to the bottom of the well. At the same time, the design of the valve assembly with its possible clogging creates a too large pressure drop in the spaces below and above the valve, reducing the effect of cooling the supports and cleaning the bottom of the sludge.

Also known is a drill bit with a nipple valve assembly [2] (prototype). In this design, most of the problems regarding the complexity and cumbersome design of the valve assembly and reducing the pressure drop in the spaces above and below the valve are resolved.

However, with the advent in our country, and especially abroad, of technologies using super-powerful compressors when drilling wells with air bottom blowing with a multiple increase in air flow (up to 70 or more cubic meters per second), the design of the bit with the indicated nipple assembly became an obstacle to their use . This is due to overheating of the compressors due to too large a pressure drop in the valve device and insufficient air flow per unit time. Compressors operating with the use of an electronic control system in these conditions “choke” and self-shut off. Therefore, there was an urgent need to develop a new type of valve with a multiple large bore for the passage of compressed air.

Since in the prototype bit the inlet in the seat and the hole in the valve washer are located one under another so that, when the valve is closed, the holes in the valve washer are under the circular surface of the seat and overlap with it, the area of these holes can only be increased by reducing the area of the hole in saddle and vice versa. This rigid ratio of areas was an insurmountable obstacle for a multiple increase in the bore in the valve.

The purpose and technical result of this invention is to increase penetration on the bit and the mechanical drilling speed by providing more efficient operation of its valve assembly.

This goal is achieved by the fact that the drill bit with a valve assembly, comprising a saddle with a central hole and a sealing coating on all sides, a washer and a return spring for it, fixing the valve assembly in the closed position, has a hanging cup with side windows, which is located on the ledge of the wall of the nipple under the saddle and has an inner diameter that is larger than the diameter of the Central hole in the saddle, while the spring loaded valve washer is made round, continuous and located inside the hanging cup with the possibility of full and tight overlap of the Central hole of the saddle in the closed position of the valve assembly.

The continuous valve washer is installed with the possibility of its snug fit to the lower end surface of the seat when the spring position is open.

The total area of the side windows in the pendant is equal to or greater than the area of the center hole of the saddle.

Figure 1 shows a fragment of a drill bit with a valve assembly of the present invention.

On the body of the bit 1 there is a threaded nipple 2, in the cavity of which a valve assembly is located, consisting of a seat 3 completely rubberized as a sealing coating, a cup 4, inside of which a continuous valve washer 5 is placed, pressed against the seat 3 by the spring 6. The stop for the spring 6 is glass bottom 4.

The saddle 3 together with the cup 4 are mounted on the ledge 7 in the cavity of the nipple 2 and are rigidly fixed with a clamp made by the locking expansion ring 8. Side holes are provided in the wall of the cup 4 — windows 9 communicating with the annular cavity 10 specially bored under them inside the nipple 2.

The valve assembly of the proposed bit works as follows.

In the process of drilling a well, a stream of cleaning agent (air) is supplied at a rate to the nipple part of the drill bit. Under the influence of this flow, the valve washer 5, together with the return spring 6, moves into the nipple cavity and passes the cleaning agent through the opened side openings of the window 9 in the cup 4 and the cavity 10 to the bottom of the well through nozzle nozzles and through filters (not shown) to cool the cavity of the supports . When the supply of the purge agent is stopped, the continuous valve washer 5, under the influence of the return spring 6, returns to its original position, pressing tightly against the surface of the seat 3, thereby reliably preventing the possibility of lifting the wellbore fluid with sludge into the tube space.

To ensure reliable operation of the valve throughout the entire cycle of the bit, the cross-section, length and outer diameter of the return spring are selected from the conditions so that in the compressed position it can provide full and unhindered opening of the side window space in the glass, and in the open position - a snug fit solid valve washers to the bottom end surface of the seat.

The direction of the cleaning agent through the side openings of the window, and not into the openings in the valve washer (as in the prototype), allowed to increase the area of the central hole in the saddle by a multiple. Since the area of the window openings in the glass wall does not prevent the increase in the area of the central hole in the saddle, it became possible to increase the total air consumption by a factor of 5 (or more).

Implementation of the proposed design of the valve assembly allowed to completely solve the problem of using heavy duty compressors for drilling wells with blowing the bottom. Other advantages of the drill bit according to the invention are also the simplicity of the device and high reliability.

This invention can be used for drilling wells with blowing the bottom of the air in various regions of the Russian Federation, CIS countries and far abroad.

The possibility of carrying out the invention is confirmed by bench and field tests of prototypes of drill bits made using the valve assemblies of the present invention.

The proposed drill bit with a simple and reliable valve assembly provides a sharp increase in penetration and mechanical drilling speed in flooded wells.

Sources of information

1. US patent No. 4154313, class. 175/318 (E 21 B 9/08), published 05/15/1979.

2. RF patent No. 2164284, cl. E 21 B 10/60, published March 20, 2001.

Claims (3)

1. A drill bit with a valve assembly, comprising a saddle fixedly on a ledge of the wall of the nipple with a central hole and a sealing coating on all sides, a valve washer and a return spring for it, fixing the valve assembly in the closed position, characterized in that it has a hanging cup with side windows, which is located on the ledge of the wall of the nipple under the saddle and has an inner diameter that is larger than the diameter of the central hole in the saddle, while the spring loaded valve washer is made round, solid and is suspended within the cup, with the full and tight overlap the central hole of the saddle in the closed position of the valve assembly. 2. The drill bit according to claim 1, characterized in that the continuous valve washer is installed with the possibility of its snug fit to the lower end surface of the seat when the spring position is open. 3. The drill bit according to claim 1 or 2, characterized in that the total area of the side windows in the hanging cup is equal to or greater than the area of the Central hole of the saddle.