SU1675548A1 - Annular pneumatic striker for drilling wells - Google Patents

Abstract

The invention relates to mining and it is intended for drilling exploration wells. The goal is to increase the operational reliability of the pneumatic impact tool while increasing the drilling depth by reducing the likelihood of cuttings entering the impact unit. To do this, an annular collar 5 is installed on the core-receiving tube (CPT) 4 installed inside the stepped tube (CT) 3, which is placed between the inlet 12 and the outlet 13 of the CT 3, which are made at its different stages. In the annular collar 5 performed by

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at least one throttling hole 6. In the front part of the body 1 of the air striker with axial movement along the CT 3 a rock-breaking tool 7 is installed with a purge channel 8 communicated with the main chamber (K) 14 through the exhaust K 15. The latter is placed between the CT 3 and CPT 4. At the same time, the cross-sectional area of the channel 8 of the tool 7 is equal to the sum of the cross-sectional areas of the holes 13 and 6. The drummer 2 and the ST 3 form K 16 of the working stroke, and together with the body 1 - K 17 of idling.

The invention relates to the mining industry, in particular, to pneumatic impact devices with pneumatic conveying of a mud material used in drilling exploration wells.

A well-known annular pneumatic hammer for well drilling includes a body, a stepped hammer with a through axial channel, the last step tube with holes for air inlet and exhaust, and a core receiver tube with longitudinal channels made on its outer surface, and a device for varying intake time during working stroke of the striker 1.

The disadvantage of an annular hammer is that due to the friction of the adjusting sleeve in the protrusions of the hammer, the operational reliability of the device is reduced.

The closest technical solution to the invention by its technical essence and the achieved result is an annular hammer, comprising a housing, a hammer, installed with the possibility of reciprocating movement along a stepped tube with inlet and exhaust openings made on different steps of a stepped tube, rigidly a core-borne pipe installed inside the latter, a rock-destroying instrument with a purge channel communicated with the main chamber through the exhaust chamber, placed stupenchat.oy between the tube and the core lifter tube 2.

A disadvantage of the known annular pneumatic impact hammer is that with an increase in the drilling depth, due to the increasing back pressure of the exhaust tract, the probability of sludge particles getting into the percussion mechanism increases, which in general

Under the action of the pressure difference in K 17 and 18, the hammer 2 makes a working stroke before striking the tool 7. In this case, the holes 12 and 13 overlap. Before the impact, the openings 12 in K 17 open, and the openings 13 in K 16, from which exhaust air comes to K 15, where it mixes with the air that has passed through the openings 6 from K 14. Next, the air flow flows through the channels 8 to the bottom. The destroyed rock is carried by this stream into the central channel of KPT 4 and further along tube 11 to the surface. 1 hp f-ly, 2 ill.

leads to a decrease in the operational reliability of the structure.

The aim of the invention is to increase the operational reliability of an impact hammer when the drilling depth is increased by reducing the likelihood of sludge falling into the impact unit.

The goal is achieved by the fact that in an annular hammer for drilling wells, including a housing, a hammer installed with the possibility of reciprocating movement along a stepped tube with inlet and exhaust holes made in different steps of a stepped tube, a core tube rigidly mounted inside the latter, rock-breaking a tool with a purge channel communicated with the main chamber through the exhaust chamber, marked up between the stepped tube and the core receiver, on the core receiver The pipe is provided with an annular shoulder, which is placed between the inlet and exhaust openings of the stepped tube, while at least one choking hole is made in the annular shoulder.

In addition, the cross-sectional area of the purge port of the rock-cutting tool is equal to the sum of the cross-sectional areas of the exhaust and throttling holes.

FIG. 1 shows a hammer, a longitudinal section; in fig. 2 shows section A-A in FIG. one,

An annular hammer for drilling wells includes a housing 1, a drummer 2, a stepped tube 3, a core receiver tube 4 provided with an annular collar 5 in which throttling holes 6 are made. In the end part of the housing 1 a rock-breaking tool 7 is axially displaced

purge channels 8. The upper part of the housing 1 is connected to a double drill pipe 9 consisting of an outer 10 and an inner 11 pipe, the latter of which is connected to a core tube A and is a continuation of the slab pipe,

In the stepped tube 3, inlets 12 and exhaust openings 13 are made. An annular shoulder 5 on the outer surface of the core receiver tube 4 is located between the inlet openings 12 and the exhaust openings 13 of the stepped tube 3 and separates the space between the walls of the stepped tube 3 and the core receiver 4 the main chamber 14 and the exhaust chamber 15, which are connected to each other through throttling holes 6, made in the collar 5.

The drummer 2 and the step tube 3 form the chamber 16 of the working stroke, and the same elements and the housing 1 form the chamber 17 of the idling.

A packer 18 is installed on the housing 1, preventing the entry of compressed air and sludge between the housing 1 and the wall of the well. Compressed air is fed through the annular space 19 of the double drill pipe 9 into the main chamber 14 formed by the walls of the core receiver tube 4. of the stepped tube 3 and the collar 5. Then the stream of compressed air is separated and runs parallel in two ways: through the throttling holes 6 to the exhaust chamber 15 formed by the walls of the core-receiver tube 4, the stepped tube 3, the shoulder 5 and the rock-breaking tool 7, and through the inlet holes 12 - into the idling chamber 17.

In the exhaust chamber 15, a pressure less than the main pressure is maintained, since this chamber communicates with the main through the throttling orifices of the bis atmosphere through the purge channels 8 of the rock-destruction tool 7.

The principle of operation of an annular pneumatic impeller for well drilling is as follows.

Compressed air from the main chamber 14 through the inlet ports 12 enters the idle chamber 17. Since, in the position shown in FIG. 1, the working stroke chamber 16 is in communication with the exhaust chamber 15 through the exhaust ports 13 (where the pressure is less than in the trunk chamber 14), the hammer 2 starts idling (upward in FIG. 1) under by the action of a force equal to the product of the pressure difference in the chambers by the difference of the areas of the upper and lower ends of the impactor 2. After the inlet holes 12 and the exhaust holes 13 are closed, the impactor continues to move in

in the same direction until the camera 16 of the stroke is communicated through the inlet ports 12 with the main chamber 14, and the idling chamber 17 via the exhaust ports 13 is connected with the exhaust chamber 15.

In the upper position of the striker 2 from the idling chamber 17, the exhaust occurs and the pressure in it drops to the value of the pressure in the exhaust chamber 15. Compressed air through the inlets 12 now flows into the working stroke chamber 16, therefore the pressure in this chamber becomes greater than in the chamber 17 idle. Under the action of the pressure difference in these chambers, the impactor 2 stops and begins to make a working stroke (in Fig. 1 downward) before striking the rock-breaking tool 7. At the same time, the inlet holes 12 and the exhaust holes 13 overlap. Before the impact of the hammer 2, rock-breaking tool 7 occurs the opening of the inlet holes 12 into the chamber 17 of idling, and the exhaust holes 13 - into the chamber 16 of the working stroke,

From the working chamber 16, exhaust air enters the exhaust chamber 15, where it is mixed with air passing through the throttling holes 6 from the main chamber 14. Next, the mixed air flow enters the bottomhole through the purge channels 8 of the rock-destruction tool 7.

Destroyed rock is picked up by this stream and carried to the central channel of the core tube 4 and then along the inner pipe 11 of the double drill pipe 9 to the surface. Packer 18 prevents air and sludge from entering the space between housing 1 and the walls of the well,

When the hammer is operating in the exhaust chamber 15, the pressure is maintained above atmospheric, but lower than the main one, since air enters the chamber through the throttling holes 6 and the exhaust holes 13 and leaves the chamber through the purge channels 8 of the rock-demolishing tool 7. depends on the area of the throttling holes 6. In this case, the cross-sectional area of the blowing channels 8 should be equal to the sum of the areas of the throttling holes 6 and the exhaust holes 13. If the area is transverse If the cross section of the purge channels 8 is smaller than the specified value, the exhaust line of the shock-relief mechanism will be constricted, resulting in a decrease in the calculated frequency and impact energy.

In addition, the pressure pulsation in the exhaust chamber 15 will increase at the moment of exhaust. If the cross-sectional area of the channels 8 is larger than the specified value, then the pressure in the exhaust chamber 15 will decrease depending on the excess area of the channels 8 up to atmospheric. The performance in this case also decreases.

If the condition of equality of the cross-sectional area of the channels 8 and the sum of the areas of the throttling holes 6 and exhaust holes 13 is met, the exhaust from the idle chambers 17 and the working 16 strokes takes place into the exhaust chamber 15, where the pressure is kept constant (with some pulsations regardless of the depth of drilling ). At the same time, the parameters of the working cycle of the pneumatic impactor are selected so that a given energy and frequency of impacts is achieved when the pneumatic impactor operates at a predetermined pressure drop.

In this case, during drilling, the hammer hammer will work with a nearly constant frequency and impact energy, regardless of the depth of the well and the corresponding value of bottomhole pressure at the base of the air column.

When using the invention, a sufficiently high level of stability of the pneumatic impact mechanism and reliability of the structure is ensured.

Claims (2)

1.Ring pneumatic hammer for well drilling, including body, drummer, mounted with the possibility of reciprocating movement along a stepped tube with inlet and exhaust openings made at different stages of the stepped tube, a core receiving tube rigidly installed inside the latter, a rock destructive tool with a purge channel communicated with the main chamber through an exhaust chamber placed between a stepped tube and a core lifter tube, characterized in that, in order to increase the operational reliability of the hammer, while increasing the drilling depth by reducing the likelihood slurry gets into the impact unit, an annular collar is made on the core-receiver tube, which is placed between the inlet and exhaust openings of the stepped tube, while in the annular collar at least one choke hole. 2. Air hammer according to claim. Characterized in that the transverse area the cross section of the purge channel of the rock-breaking tool is equal to the sum of the cross-sectional areas of the exhaust and. throttling holes.