RU2234585C1 - Device for forced flushing and oiling bit bearing assembly - Google Patents

Abstract

FIELD: drilling equipment, particularly device for drilling wells in mining industry with the use of roller bit with possibility of central scavenging and cleaning bottom hole by air-to-water mixture.

SUBSTANCE: device has sub with sleeve and nipple cavities separated by partition in central parts thereof and communicating one with another through longitudinal peripheral axial orifices, diametrical blind bore arranged transversely to longitudinal sub axis and having groove. Groove coincides with longitudinal peripheral orifices. Bushing with side windows communicating with axial orifice is arranged in blind bore. Roller bit is connected with sub sleeve. Roller bit has channels formed in bit legs for scavenging and oiling bit bearing assembly. Device also has central scavenging nozzle with tube fixed inside thereof. Free tube end passing into sleeve cavity is located in axial orifice. Spring-loaded single-flow end cap with slot-like orifice is rotatably installed inside busing. End cap has neck with shaped end. End cap is fixed by round nut and washer with tooth inserted in end cap groove so that slot-like orifice coincides with axial sub orifice.

EFFECT: simplified structure, increased reliability.

1 dwg

Description

The invention relates to the drilling of wells in the mining industry by roller cone bits with the cleaning of the bottom by an air-water mixture. When drilling such wells, cone bits with unsealed cones, with central blowing of the bottom and with channels in the paws are used to guide some part of the purge and flushing agent into the bearings to cool the bearings and prevent the penetration of sludge into the cavity of the bearings.

However, these measures do not preclude the penetration of sludge into the bearings of the cones during periods of increasing the drill string or disassembling it after the completion of drilling and shutting down the purge. In order to avoid clogging of the supports, when performing these operations, reverse sludge protection valves are used that fix the bits in the central purge hole, but even then the cuttings and particles of the destroyed rock scraped from the walls of the well by cones when the bit is raised penetrate the supports and each new well begins to be carried out with slammed supports. To eliminate this extremely undesirable phenomenon, devices are used for forced washing and lubrication of the bit supports (ed. Certificate of the USSR No. 1465532 or No. 1465533, MKI E 21 B 10/18, publ. B.I. No. 10, 03/15/89).

However, these devices have the significant disadvantage in that they use composite adapters with the possibility of relative axial or angular movement of the connected parts. When wells are drilled with cone bits, especially in hard and fractured rocks, longitudinal and radial vibrations with high dynamic loads are inevitable, which causes riveting, jamming and destruction of the connected parts.

These shortcomings were eliminated in the roller bit for drilling with the use of a gaseous cleaning agent (ed. Certificate of the USSR No. 1444501, MKI E 21 B 10/08, publ. BI No. 46, 1988), which is the closest in technical essence and the achieved results to this invention and adopted by us as a prototype.

The prototype contains an adapter with a nipple and coupling cavity, in the middle part of which there is a radial hole perpendicular to the longitudinal axis of the bit, axial and peripheral holes communicating the nipple and coupling cavity, roller cone having cones with supports, a housing with an axial purge channel, channels in paws for purging and lubricating the bearings of the cones, a check valve installed in the radial bore of the sub and made in the form of a sleeve and a cylindrical piston with a central and radial holes and possibly the way the piston exits.

The disadvantage of this cone bit is a significant weakening of the mechanical strength of the sub, since a through hole of increased diameter is perpendicular to its longitudinal axis, and then a check valve is installed in it in the form of a sleeve and a spring-loaded piston, which practically obscures the entire cross section for the passage of the purge-flushing agent in the bearings of the cones when washing the bearings, leaving only a small annular section between the piston shaft and the sleeve for passage of the flow into the bearings, which besides, it is partially occupied by spring coils.

The next disadvantage of the prototype is the technological difficulty of performing the main channels for passing the purge-flushing agent into the bottom of the well during drilling, which requires the milling of the figured grooves in the sub housing with subsequent welding from the outside of the plates to seal the channels.

The invention is aimed at simplifying the design and improving the manufacturing technology of the device for forced washing and lubrication of the supports of the bit.

This is achieved by the fact that in the device for forced washing and lubrication of the bit supports, containing a sub with a coupling and nipple cavities, separated by a partition in the middle part, interconnected by longitudinal peripheral and axial holes, a diametrical blind hole made perpendicular to the longitudinal axis of the sub, in which formed a groove matching the peripheral longitudinal holes, and a sleeve is located with side windows facing the cavity of the axial hole, rolling cutter, soy dinned with a sub clutch, having channels in the paws for purging and lubricating the supports and a central purging nozzle with a tube fixed in it, the free end of which extends into the coupling cavity and installed in the axial hole, a spring-loaded single-pass plug with a slotted hole is mounted with the possibility of angular rotation having a neck with a profile end for a socket wrench, secured from the outlet by a ring nut and a washer with a tooth entering the groove of the plug, so that in the initial and working position of the bit the slotted the plug hole coincided with the axial hole of the sub, in the mouth of which a check valve is installed on the side of the nipple cavity.

The invention is illustrated by the drawing, which shows a vertical section of a device for forced washing and lubrication of the supports of the bit.

Positions on the drawing indicate: 1 - sub; 2 - coupling cavity; 3 - nipple cavity; 4 - longitudinal peripheral holes; 5 - axial hole; 6 - diametrical blind hole; 7 - groove; 8 - sleeve; 9, 10 - side windows; 11 - roller cone bit; 12 - channels for purging and lubricating the supports; 13 - Central purge nozzles; 14 - tube; 15 - spring-loaded plug; 16 - spring plugs; 17 - ring nut; 18 - washer; 19 - profile tooth; 20 - slotted hole; 21 - check valve.

A device for forced washing and lubrication of chisel supports comprises: a sub 1 with a coupling 2 and a nipple 3 cavities separated by a partition in the middle, interconnected by longitudinal peripheral 4 and axial 5 holes, a diametrical blind hole 6 made perpendicular to the longitudinal axis of the sub 1, in which a groove 7 is formed, which coincides with the peripheral longitudinal holes 4, and a sleeve 8 is located with side windows 9 and 10 extending into the cavity of the axial hole 5, a cone bit 11 connected to a sub clutch 7 having channels 12 in the paws for purging and lubricating the supports, a central hole and a central purge nozzle 13, with a tube 14 fixed therein, the free end of which extends into the coupling cavity 2 and installed in the axial hole 5, inside the sleeve 8 is installed with with the possibility of angular rotation, a spring-loaded single-pass plug 15 with a profile neck for a socket wrench, fixed from the outside by an annular nut 17 and a washer 18 with a tooth 19, which enters the groove of the plug 15, so that the slot 11 in the initial working position of the bit 11 Tube 15 e 20 coincides with the axial hole 4 sub 1, in which the mouth of the cavity by the nipple 3, a check valve 21.

The proposed device for forced washing and lubrication of the supports of the bit works as follows.

Before starting the drilling of a well with a new cone bit 11 with factory grease in the cone bearings, it is connected to a sub 1 and a purge-flushing agent is injected into the drill string (not shown), which enters the nipple cavity 3, from which it is supplied through peripheral longitudinal holes 4 goes into the coupling cavity 2, the cavity of the nipple of the cone bit, and from it through the channels 12 it enters the purge of the cones of the cones. In addition, from the nipple cavity 3, through the side windows of the valve 21, the purge-flushing agent enters under the valve cup 21, lifts it up, opens a passage into the axial hole 5 and goes through the windows 9 and 10, the slot hole 20 of the plug 15, the tube 14 and nozzles 13 to the bottom of the well to take out the destroyed rock. This is the operating mode for bottom hole cleaning during drilling.

After the well is drilled and the bit is raised to the surface, the purge of the well is turned off, and a new drilling point is moved to another well.

The socket wrench is put on the profile end of the neck of the plug 15, it is shifted to the center of the sub 1, compressing the spring 16 until the tooth 19 of the washer 18 comes out of the groove of the plug 15, then it is rotated 90 ° in any direction, while the axial hole 5 will be blocked by plug 15 and the passage of the purge-flushing agent through nozzles 13 will be impossible.

Having completed these operations, the purge-flushing agent is supplied to the drill string. Now, entering the nipple cavity 3, the purge-flushing agent through the longitudinal peripheral holes 4 goes into the nipple of the bit 11, and from it through the purge channels 12 rushes into the cavities of the cone supports under high pressure, intensively blowing and cleaning them from sludge and rock particles. To enhance cleaning of the supports, an increased amount of liquid is added to the purge stream. After abundant washing, the supply of liquid to the bearings is stopped, and mineral oil or another lubricating agent is fed into the purge stream and the bearings of the bearings are lubricated.

After completing the flushing and lubrication operations, they stop supplying the flushing and flushing agent, finally install the machine at a new drilling point and begin drilling the well with completely clean and well-lubricated bearings.

We found during field experiments that forced washing and lubrication of the supports increases the penetration of the bits to wear at least 1.8-2 times.

Claims (1)

A device for forced washing and lubrication of bit supports, comprising a sub with a coupling and nipple cavities separated by a partition in the middle, communicating with each other by longitudinal peripheral and axial holes, a diametrical blind hole made perpendicular to the longitudinal axis of the sub, in which a groove is formed that coincides with peripheral longitudinal holes, and a sleeve is located with side windows facing the cavity of the axial hole, roller cone connected to the clutch ka having channels in the paws for purging and lubricating the supports and a central purge nozzle with a tube fixed in it, the free end of which extends into the coupling cavity and is installed in the axial hole, characterized in that a spring-loaded single-pass plug with a slot is installed inside the sleeve with the possibility of angular rotation a hole having a neck with a profile end, fixed with an annular nut and a washer with a tooth entering the groove of the plug so that its slot hole coincides with the axial hole of the sub.