RU2235182C1 - Device for forced flushing and oiling of drill bit bearing assembly - Google Patents

Abstract

FIELD: well drilling equipment, particularly for well drilling with the use of roller bit and for bottomhole washing with water-and-air mixture.

SUBSTANCE: device comprises sub with nipple and bushing cavities separated one from another by partition arranged in central part thereof, axial orifice formed in central sub part, spring-loaded piston installed in axial orifice and having rod extending in bushing cavity, peripheral orifices connecting with sub chambers, radial orifice with plunger communicating with axial orifice and with nipple chamber by peripheral longitudinal channel. Radial orifice also communicates with outer space through horizontal orifice. Device has roller bit connected to sub bushing and having channels in sub legs and central flushing nozzle provided with check valve and spacing tube which extends into bushing cavity during well flushing over a distance equal to valve stroke. Rod remains in initial position during flushing process due to establishing communication between nipple cavity and rod cavity through longitudinal channel. When forced bit drilling assembly flushing and oiling plunger is manually moved to sub center for closing channel and opening horizontal channel for communicating rod cavity orifice with ambient space. Rod is moved downwards to prevent valve opening and the whole flushing flow is directed to bit bearing assembly for flushing and oiling thereof before new well drilling.

EFFECT: simplified structure, improved production technology.

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 driving such wells, cone bits with unsealed cones 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, this measure does not preclude the penetration of sludge into the cones during the periods when the drill head is being built up or disassembled after the completion of drilling and shutdown off. To avoid clogging of the supports, when performing these operations, reverse sludge protection valves are used that fix the bits in the central blowing 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, use devices for forced washing and lubrication of the supports of the bit (ed. Certificate. USSR No. 14655532, No. 1465533, MKI E 21B 10/18, publ. BI 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 drilling holes 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. USSR # 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 body with an axial purge channel, channels in the paws for lubrication of cones, 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 the possibility of exit EDSS out.

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 made 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 into cones when flushing the supports, leaving only a small annular section between the piston shaft and the bushing, which the same is partially occupied by spring coils.

The next disadvantage of the prototype is the technological difficulty of implementing 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 of the plates to seal the channels from the outside.

Another major drawback of the prototype is that the central cone of the cone bit is connected at one end to the central purge hole, and the other end must enter the axial channel of the sub, ensuring the tightness of the movable connection, which requires very precise centering and verticality of the channels and holes in the manufacture of products on various enterprises (chisel factories and drilling rig factories).

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, comprising a sub with a coupling and nipple cavities separated by a partition in the middle part, in which axial and peripheral longitudinal holes are formed, communicating the nipple and coupling cavities, a radial hole connecting to the axial hole and outer space, a plunger located in the radial hole and secured in it with a ring nut from the outlet to the outside and pressed by a spring to the inner end of the nut, roller cone connected to the coupling of the sub, having channels in the paws and a central hole with a purge nozzle, in which a sludge-proof check valve is fixed with a remote tube that goes into the coupling cavity, a spring-loaded piston is installed in the axial hole of the sub, the rod of which goes into the coupling cavity and is located from the top the end of the remote tube at a distance h equal to the stroke of the sludge protection valve, the cavity of the radial hole in front of the end of the plunger facing the center of the sub, the longitudinal periphery the channel is connected to the nipple cavity, and the rod cavity of the axial hole with a horizontal channel having an exit to the radial hole is connected to the outer space, and the exit of the horizontal channel to the radial hole in the initial and working position of the bit is closed by the plunger with the possibility of opening it when the plunger is shifted to the center during flushing of the drill supports and closing of the longitudinal peripheral channel.

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 - axial hole; 5 - peripheral holes; 6 - radial hole; 7 - roller cone bit; 8 - purge channels of supports; 9 - central purge nozzles; 10 - sludge protection valve; 11 - a remote tube; 12 - a piston; 13 - stock; 14 - a plunger; 15 - ring nut; 16 - spring; 17 - longitudinal peripheral channel; 18 is a horizontal channel.

A device for forced washing and lubrication of the bit supports comprises an adapter 1 with a coupling 2 and a nipple 3 cavities separated by a partition in the middle part, in which axial 4 and peripheral longitudinal 5 holes are formed, communicating the nipple and coupling cavities, a radial hole 6 communicating with the axial hole 4 and the outer space, the plunger 14, located in the radial hole 6 and secured in it with a ring nut 75 from the outlet to the outside and pressed by a spring 16 to the inner end of the nut 15, roller cone 7, connected with a sub clutch 1, having channels 8 in the paws for purging and lubricating the bearings, a central hole with a purge nozzle 9, in which a sludge protection valve 10 is mounted with a remote tube 11 extending into the coupling cavity 2, a spring-loaded piston 12 is installed in the axial hole 4 of the sub 1 , the rod 13 of which goes into the coupling cavity 2 and is located from the upper end of the distance tube 11 at a distance h equal to the stroke of the sludge protection valve 10, the cavity of the radial hole 6 in front of the end of the plunger 14 facing the center of the sub and 1, the longitudinal peripheral channel 17 is connected to the nipple cavity 3, and the rod cavity of the axial hole 4 of the horizontal channel 18 having an exit to the radial hole 6 is connected to the outer space, and the output of the horizontal channel 18 to the radial hole 6 in the initial and working position of the bit 7 is closed by the plunger 14 with the possibility of opening it when the plunger 14 is displaced to the center while blowing the supports of the bit 7 and closing the longitudinal peripheral channel 17.

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 bit 7 with the presence of factory lubrication in the cones, 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 goes to the coupling through peripheral holes 5 cavity 2, through the side windows in the sludge protection valve 10 penetrates under the valve cup and lifts it up, compressing the spring, opens the passage to the purge nozzles 9 and enters the bottom of the well to take out the destroyed rock, the remote pipe 11 is fixed in the cup, it enters the coupling cavity 2 by an amount of h until it contacts the end face of the rod 13, which remains in its original position, since the purge-flushing agent through the longitudinal peripheral channel 17 and the radial hole 6 enters the rod cavity of the axial hole 4, trying to raise the piston 12 is upward, the force of the pre-compressed spring of the piston 12 also acts in the same direction, in total they are taken more than the force acting on the piston 12 from the side of the nipple cavity 3. Thus, drilling and cleaning of the well takes place.

After the well is drilled and the bit is raised to the surface, the purge of the well is turned off, it is moved to a new drilling point of another well, with a screwdriver or other metal rod of the corresponding diameter through the hole in the ring nut 15, the plunger 14 is displaced to the center of the sub 1, while the channel 17 the cavity of the hole 6 is blocked by the plunger 14, and the output of the horizontal channel 18 opens and communicates the outer space, where the pressure is atmospheric, with the rod cavity of the axial hole 4.

Now turn on the supply of the purge-flushing agent, it enters the nipple cavity 3, presses on top of the piston 12 and shifts it down by an amount h to the stop in the upper cover of the sludge protection valve 10, preventing the outlet of the remote tube 11 into the coupling cavity 2. If the remote tube 11 manages to exit into the cavity 2, the stem 13 will certainly return it to its original position, since the lifting force of the valve 10 is less than the force acting on the piston 12 from top to bottom, so the valve 10 will be closed, purge-flushing agent, entering into the coupling cavity 2, will go into the nipple of the bit 7 and then through the channels 8 to the cone supports, intensively blowing them at maximum pressure, at this time as much water as possible is added to the purge stream and the supports are washed, then the water is closed, adding to the stream lubricant, and lubricate bearings bearings. After completing the flushing and lubrication operation, the purge-flushing agent is shut off, the machine is finally installed at the drilling point, and a new well is drilled with completely clean and well-lubricated bearings.

We found that forced washing and lubrication of the supports increases their durability by 1.8-2 times.

Claims (1)

A device for forced washing and lubrication of chisel supports, comprising an adapter with a coupling and nipple cavities separated by a partition in the middle part, in which axial and peripheral holes are formed, communicating the nipple and coupling cavities, a radial hole connecting to the axial hole and the outer space, a plunger, placed in a radial hole and secured in it with a ring nut from the exit to the outside, pressed by a spring to the inner end of the nut, a cone bit connected to a coupling of the sub channels in the paws and a central hole with a purge nozzle in which a sludge-proof check valve is fixed with a remote tube exiting into the coupling cavity, characterized in that a spring-loaded piston is installed in the axial bore of the sub, the rod of which goes into the coupling cavity and is located from the upper end of the remote tube at a distance equal to the stroke of the sludge protection valve, the cavity of the radial hole in front of the end of the plunger facing the center of the sub, the longitudinal peripheral channel of the connection it has a nipple cavity, and the rod cavity of the axial hole with a horizontal channel having an exit to the radial hole is connected to the outer space, and the exit of the horizontal channel into the radial hole in the initial and working positions is closed by the plunger with the possibility of opening it when the plunger is displaced to the center during washing bit support and closure of the longitudinal peripheral channel.