JPS58160490A - Air lift - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to fluid pneumatic actuated devices, and more particularly to air lifts.

The invention is used to drill boreholes with reversible circulation, whereby pipe circulation occurs when drilling fluid is transferred from the space behind the pipe to the drill pipe for pipe transport.

The invention may be used in any other technical field where pneumatic actuation of fluids is required.

As is well known, air lifts are designed to supply compressed air to a drill pipe along a pipe surrounding the drill pipe.

Known airlifts have an annular chamber created by a cylindrical sleeve surrounding a drill pipe;
It is installed inside the pipe that supplies compressed air.

The annular chamber communicates with the cavity of the drill pipe through an annular slit made in the wall of the drill pipe.

The lower end wall of the annular chamber has openings made therein, each opening overlapped by a check valve provided on a projection of the drill pipe and made below the lower end wall of the annular chamber. .

Known air lifts are designed for the most efficient operation, e.g.
It is not suitable for supplying compressed air to areas up to a depth of 0 meters.

To clarify this point, consider operating a known air lift using a high pressure compressor.

It is well known that drilling methods with reversible fluid circulation start from a depth of approximately 20 meters.

Descending from this depth, the borehole is drilled in the usual manner, where the drill pipe is withdrawn, an air lift is attached to the drill pipe in contact with the drill bit, and the drill pipe is drilled until it contacts its surface. Applied to the hole. The compressor is then activated and the wellbore is drilled for a period of reversible circulation.

As the drill hole gets deeper, the air lift goes further down and the compressor increases the pressure of the compressed air in order to supply compressed air to the internal cavity of the drill pipe and to overcome the hydraulic pressure at a certain depth. the total power dissipated by the compressor.

For example, digging a borehole up to 190 meters deep would use 100% of its maximum power;
A high pressure compressor is used to supply compressed air.

When using a low pressure compressor, the borehole is drilled to a depth of 20 meters by conventional methods. The drill pipe is then withdrawn from the wellbore, an air lift is mounted near the drill bit, and the drill pipe is moved into the wellbore until it contacts that face. The compressor is then activated and drilling continues for a period of time during which the wellbore is reversibly circulated.

As the drill hole becomes deeper, the air lift moves downward and downward until the pressure from the compressor no longer supplies air to the mixer due to the hydraulic reaction of the fluid in the drill pipe.

When the air lift reaches a depth of 40 meters, the drill pipe is pulled out of the drill hole, the air lift is removed and reattached to the drill pipe at a distance of 20 meters from the surface, so that the drill pipe is inserted into the drill hole. excavation will continue.

Thus, when drilling holes up to 150 meters deep, it is necessary to move the drill pipe in and out six times in order to displace the air lift to the area of best load, which increases the time of drilling. The present invention is to provide an air lift with check valve and circulation chamber designed to have low power consumption and high excavation speed.

This task is achieved by an airlift having an annular chamber formed around the drill pipe, which is connected to the pipe supplying compressed air via a check valve, which according to the invention It has a body formed by a cylindrical sleeve disposed around and coaxial with the pipe, the inner surface of which has an upper part of larger diameter and a lower part of smaller diameter, similar to drill pipes and radial ends. , a plunger located in the body is biased upwardly by a spring and forms a variable volume chamber within the body having a lower portion of larger diameter and an upper portion of smaller diameter, which is connected to an opening in the radial end of the body. in communication with a pipe for supplying compressed air through and through a passage made in the plunger, the inner lower part of the cylindrical sleeve defining an annular cavity of variable volume with the outer surface of the upper part of the plunger. forming an annular shape formed by the inner cylindrical surface of the plunger and an annular hole drilled in the wall of the drill pipe by moving the plunger downwardly and communicating with the space behind the pipe through a radial opening in the cylindrical sleeve. The chamber is adapted to communicate with a variable volume chamber provided above the trill pipe 1 and the plunger during the downward movement of the latter.

The specific structure of this air lift is such that when the air lift reaches a certain depth in the borehole, it automatically moves from the variable volume chamber above the plunger to the cavity of the drill pipe through an annular chamber and an annular slit. allows compressed air to be sent to

In the air lift according to the invention, the plunger is made stepwise and has a cylindrical shape and forms a chamber of variable volume. One of the chambers communicates with the cavity of the drill pipe via an annular chamber and an annular slit. By communicating the variable volume annular cavity with the space behind the pipe, the plunger can be automatically moved downward, and compressed air can be sent from the variable volume chamber through the annular chamber to the cavity of the drill pipe. I can do it.

The radial opening and the annular hole communicate with each other from their insides to connect the chamber of variable volume above the plunger with the annular chamber above the cylindrical wall of the plunger, and the annular hole with the elastic ring connects the chamber with a variable volume above the plunger to the annular hole with the elastic ring. It is a good idea to overlap when the is in its lower position.

This connection directs compressed air from a variable volume chamber above the plunger through a radial opening in the internal cylindrical wall of the plunger, an annular hole communicating with each other, and an annular chamber when the plunger is in its lowermost position. Designed to be delivered into a drill pipe cavity.

A resilient ring in the annular hole prevents fluid within the drill pipe cavity from entering the variable volume chamber through the radial opening. This can clog variable volume chambers and drill pipes or supply dirty compressed air to pipe cavities.

Preferably, a split ring spring is constructed above the outer cylindrical wall of the plunger, which acts on the lower part of the inner surface of the cylindrical sleeve to hold the plunger in its lower position.

The ring-shaped spring is made of an elastic material such that its diameter stretches when it is located in the lower part of the cylindrical sleeve, for example.

8- The air lift of this particular construction is adapted to hold the plunger in its lower position, so that during operation of the air lift, pulses of compressed air are supplied from the compressor to the space behind the pipe. The pulsation of the fluid inside does not affect the axial movement, which allows a stable supply of compressed air to the drill pipe.

The above-mentioned features and advantages of the invention will be better understood from the following specific examples explained with reference to the accompanying drawings.

The air lift is designed to supply compressed air to the drill pipe 1 (FIG. 1).

The air lift according to the present invention has an annular chamber 3 formed around a drill pipe 1 and communicates with the chamber 3 through a check valve 4 with a pipe 2 for supplying compressed air. As shown in Figure 1, pipe 2
are arranged parallel to the drill pipe 1 and are connected by a clamp 5 arranged perpendicularly to the axis 6 of the drill pipe 1.

The check valve 4 has a body 7 formed from a cylindrical sleeve 8 and a radial end 9, which is arranged around the drill pipe 1 and is coaxial with the wall of the drill pipe 1.
has.

The radiating end 9 is fixed to the drill pipe 1 in this particular case as shown in FIG.

The inner surface of the cylindrical sleeve 8 has a lower part 1 with a larger diameter.
0 and an upper part 11 having a small diameter.

The check valve 4 has a pusher 12 included in the main body 7. The inner wall 12a of the plunger 12 is longer than the outer wall 12b, which is in contact with the outer wall of the drill pipe 1 and is in contact with the inner surface of the cylindrical sleeve 8, so that the inner wall 12a
depends on the radial end 9 of the body 7.

This ensures that plunger 12 is fixed in its upper position. The plunger 12 consists of a lower part 13 with a larger diameter and an upper part 14 with a smaller diameter.

The plunger 12 is arranged along the axis 6 of the drill pipe 1.

A spring 15 is provided below the plunger 12 in the body 7 to press the plunger 12 upwardly, and the movement of the spring 15 is arranged coaxially with respect to the drill pipe 1 and with the inner surface of the lower part 10 of the sleeve 8. It is regulated by the contacting cylindrical sleeve 15a.

In the body 7, the plunger 12 forms an upper variable volume chamber 16 and a lower variable volume chamber 17.The chamber 16.17 forms an opening 18. It communicates with the pipe 2 via 19.

A circular hole (not shown) is made in the radial end 9, through which the end of the pipe 2 passes and is welded thereto.

Chambers 16 and 17 communicate via a coaxial passage 20 formed in plunger 12.

Several passages are provided along the circumference and along the axis of the drill pipe 1.

The lower part 10 of the inner surface of the cylindrical sleeve 8 forms an annular hole 21 with the outer surface of the plunger 12 so as to increase the variable volume when the plunger 12 moves downwardly. A radial opening 22 is formed spatially within the cylindrical sleeve 8 .

The annular hole 21 communicates with the back of the pipe through a radial opening 22, which supplies fluid to the annular hole 21 and cooperates with the end of the lower part 13 of the Pushinger 12.
is designed to move downward.

Check valve 4 is automatically energized at a certain depth.

The drill pipe 1 has an annular bore 23 forming an annular chamber 3 with the inner cylindrical surface of the plunger 12;
This is an annular slit 24 made in the wall of drill pipe 1.
It communicates with the hole through.

A radial opening 25 is made in the upper part of the inner cylindrical wall 12a of the plunger 12, which communicates with an annular bore 26. A hole 26 is then made in the inner cylindrical wall of plunger 12.

The radial opening 25 and the hole 26 connect the annular chamber 3, which is adapted for the passage of compressed air when the plunger 12 is in its lower position, and a chamber 16 of variable volume located above the plunger 12. It is designed to pass.

As mentioned above, the hole 23 communicates with the cavity of the drill pipe through an annular slit made in the wall of the drill pipe 1.The end of the annular slit 24 is connected to the drill pipe so that the compressed air flows directly upwards. 1 at a certain angle with respect to the axis 6.

During downward movement of the plunger 12, the annular hole 23 communicates with the variable volume chamber 16 to pass compressed air from the pipe 2 to the drill pipe 1.

The hole 26 has an elastic ring 27 which keeps the chamber 16 in the upper part of the plunger 12 during the connection between the drill pipe already in operation and another drill pipe 1.
Fluid is prevented from flowing from the cavity of the hedrill pipe 1.

An annular hole 28 is made in the upper part of the outer cylindrical wall 12b of the plunger 12.

The hole 28 has a segmented annular spring 29 which cooperates with the lower part 10 of the inner surface of the sleeve 8 to keep the plunger 12 in its lower position.

This makes it possible to fix the plunger 12 so that during operation of this air lift, the compressed air supplied from the compressor (not shown) and the pulsation of the fluid behind the pipe are not applied to the plunger 12. That's what I do. This causes discontinuity in the communication between the variable volume chamber 16 and the annular chamber 3 and the communication between the annular slit 24 and the cavity of the drill pipe 1.

A hole (not shown) with a sealing ring 30 is made in the outer wall 12b of the upper plunger 12 of the annular hole 28.

During cooperation with the upper part 11 of the inner surface of the sleeve 8, the ring 3
0 seals the chamber 16 from the annular hole 21.

The annular hole 21 communicates with the space behind the pipe via a radial opening 22.

This arrangement of the sealing ring 30 prevents the penetration of compressed air from the chamber 16 into the space behind the pipe through the gap between the outer wall 12b of the plunger 12 and the upper part 11 of the inner surface of the sleeve 8; This prevents fluid from flowing into the chamber 16 from the space behind the pipe while air is not being supplied to the air lift.

This occurs, for example, when another drill pipe is connected.

The lower part 13 of the plunger 12 also has an annular bore (not shown) made therein and forming a sealing ring 31.

The sealing ring 31 seals the chamber 17 when the lower part 13 of the plunger 12 and the lower part 10 of the inner surface of the sleeve 8 cooperate.

This arrangement of the ring 31 makes the lower part 1 of the plunger 12
3 and the lower part 10 of the inner surface of the sleeve 8 from the chamber 17 to prevent compressed air from penetrating into the space behind the pipe during operation of the air lift, and to prevent compressed air from being supplied to the air lift. This prevents fluid from flowing from the space behind the pipe to the chamber 17 when the pipe is not in use.

This happens, for example, when connecting to another drill pipe.

The inner wall 12a of the plunger 12 has a sealing ring 32 that seals the chamber 1 above and below the plunger 12.
6.17 from the cavity of the drill pipe 1 and the annular chamber 3.

This arrangement of the sealing ring 32 allows the air to flow from the chamber 16,17 via the gap between the inner wall 12 of the plunger 12 and the wall of the drill pipe 1 into the annular chamber 3 before the air lift reaches its energized depth. Try not to reach it.

In this way, all the compressed air supplied from the compressor is distributed to the operating airlift without losses.

Figure gg2 shows a modification of a specific example of an air lift, in which a pipe 2a supplying compressed air to the drill pipe 1 is arranged coaxially with respect to the pipe 1.

As in the previous example, an annular chamber 3 is formed around the drill pipe 1 and connects the pipe 2 via a check valve 4a.
The check valve 4a is in communication with a cylindrical sleeve 8a mounted around the drill pipe 1 and a radial end 9a made with the drill pipe 1 in a manner coaxial therewith with the drill pipe 1 and the wall. It has a main body 7a formed from.

The inner surface of the cylindrical sleeve 8a has a larger diameter lower portion 10.
and an upper portion 11a having a small diameter.

The check valve 4a has a plunger 12c provided in the body 7a along the axis. The inner wall (not shown) of the plunger 12c is in contact with the outer wall of the drill pipe 1,
Plunger 1 in contact with the inner surface of cylindrical sleeve 8a
It is made longer than the outer wall of 2c (not shown).

The plunger 12e has a lower portion 13a with a larger diameter and an upper portion 14a with a smaller diameter.

Spring 15 in body 7a below plunger 12a
b, presses the plunger 12c upward as in the previous example, and the movement of the spring 15b is regulated by a cylindrical sleeve. The main body 7a has a chamber 1 with a variable volume ht disposed above the plunger 12c.
6a and a variable volume chamber 17a disposed below the plunger 12c. Similar to the previous example,
The chamber 16a r 17a communicates with the pipe 2a via a passage 20a made in the plunger 12e and defines a space along its periphery.

The lower part 10a of the inner surface of the cylindrical sleeve 8a forms, together with the outer surface of the plunger 12c, an annular cavity 21a with a volume that increases as the plunger 12c moves downwards.

The cylindrical sleeve 8a has a radial opening 22 made therein, and an annular cavity 21a communicating with the space behind the pipe.

An annular hole 23 is made in the wall of the drill pipe 1 from the outside, which together with the inner surface of the plunger 12c forms an annular chamber 3, and which allows the drill to be drilled through an annular slit 24 made in the wall of the drill pipe 1. It communicates with the cavity of pipe 1.

A radial opening 25a and an annular bore 26a communicating together are formed in the upper portion of the inner cylindrical wall of the plunger 12c, and the radial opening 25a and the annular bore 26g are in communication with the chamber 16.
a is designed to communicate with the annular chamber 3.

In the annular hole 26a there is a resilient spring/tube so as to overlap the radial opening 25a when the Pushinger 12c is in its lower position.
27a is provided.

An annular hole 28a creating a segmented annular spring 29a is made above the outer cylindrical portion of Pushinger 12c.

As in the previous example, sealing ring 30a + 31a *
32a is provided.

The air lift constructed in accordance with the invention and shown in FIG. 1 operates as follows.

The drill pipe 1 attached to the air lift is placed directly into a pre-drilled hole on a drill bit (not shown).

Upon reaching a depth of about 20 meters, the hydraulic pressure of the fluid in the space behind the pipe begins to act through the radial opening 22 in the area of the end of the lower part 13 of the plunger 12.

19- Under the action of such forces, the force of the spring 15 under the plunger 12 is chosen to be less than the hydraulic pressure acting on the plunger 12 at a depth of about 20 meters. , the plunger 12 begins to move downward.

During the downward movement under the action of hydraulic pressure, the plunger 12 moves into the chamber 1 above it.
6 communicates with the annular chamber 3, and the annular slit 2
4 and also communicates with the cavity of the drill pipe 1.

Air then begins to be supplied by a compressor (not shown) and the excavation operation begins.

When the depth of 40 meters is reached, the other drill pipe 1
is connected to the drill pipe and drilling of the borehole continues.

At this time, since the air lift of the upper drill pipe is not yet in a region where the pressure is sufficient to move Pushinger 12 to the lowest end, it is the lower drill pipe that is operating.

For this reason, the chamber above Pushinger 12 - 2
- 16 and the cavity of the pipe 2 supplying compressed air do not communicate with the annular chamber 3 and the compressed air does not reach the internal cavity of the drill pipe 1;

The compressed air therefore passes through the passage 20 of the plunger 12 into the cavity of the lower part of the pipe 2 and from the latter from the upper drill pipe 1 with air lift to the chamber 17 below the plunger 12 of the former. . And since at this depth the hydraulic pressure is moving the plunger of the other drill drill with air lift to its lowest point, the chamber 16 below the plunger 12 is in communication with the annular chamber 3 and the latter It also communicates with the annular slit 24 and the cavity of the drill pipe 1 through O. Eventually, the fluid in the drill pipe 1 is injected at this depth, and due to the difference in the specific gravity of the space behind the pipe and the fluid in the drill pipe 1, The waste water rises along the drill pipe.

Upon reaching a depth of 20 meters, the hydraulic pressure in the space behind the pipe is forced downwards of the pusher 12 through the radial opening 22 of the annular sleeve 8 with a force that exceeds the force of the spring 15 under the plunger 12. It begins to act on the end of section 13. Then the latter starts moving downward and plunger 1
The upper chamber of 2 begins to communicate with the annular chamber 3.

As soon as this occurs, the compressed air reaches the cavity of the drill pipe 1 and the upper air lift begins to operate.

At this point, the first drill pipe with air lift is at a depth of 40 meters, which is located in the annular chamber 3
This means that the hydraulic pressure within is equal to 4 atm, and it is easier for compressed air to overcome the reaction of 2 atm acting in the area of the next air lift than the 4 atm acting in the area of the first air lift. It is. As a result,
The first air lift stops working because the compressed air does not reach it.

Thus, the borehole is drilled by equipping a new drill pipe with an airlift every 20 meters, whereby each successive airlift alternates with the previous one every 20 and 40 meters in depth.

The air lift shown in Figures 2 and 3 operates similarly to that described above.

There have been several experimental samples fabricated of drill pipes with air lift according to the present invention, which have passed the tests.

Experimental samples have also proven their potential in operation,
For example, the most effective depth has been briefly demonstrated.

The air lift according to the invention is simple to operate and generally inexpensive.

[Brief explanation of the drawing]

FIG. 1 is a partial cross-sectional view of an airlift according to the invention. FIG. 2 is a diagram in which a pipe for supplying compressed air is arranged coaxially around a drill pipe. FIG. 3 is also similar to FIG. 2 with respect to the axis of symmetry in operation. 1.1a...Drill pipe = 23- 2.2a...Pipe for supplying compressed air 3...Annular chamber 4.4a...Check valve 5...Clamp 6...Shaft of drill pipe 7.7a...Body 8, 8a...Cylindrical sleeve 9.9a...Radial end 10, 10a...-Sleeve 8a...Lower part 11 of inner surface of 8a, lla...Sleeve 8, Upper part 12 of the inner surface of 8a, 12c...Plunger 12a...Inner wall 12b of Pushinger...Outer wall 13 of the plunger 13, 13a...Lower part 14 of the plunger 1
4a... Upper part 15 of Pushinger, 15b...
Spring 15a...Sleeves 16, 16a...Variable volume chamber 17, 17a...Variable volume chamber 24 below the plunger 18.19...Opening 20 at the radial end, 20a...passage 21, 21a...annular cavity 22...annular opening 23...annular hole 24 of drill pipe...annular slit 25, 25a...radial opening 26, 26a...annular hole 27, 27a... Elastic ring 28, 28a... Annular hole 29, 29a... Ring spring 30*30a*31t 31a*32
*32a”・Sealing Ring Patent Applicant Representative Patent Attorney Fumi Sato (and 1 other person)

Claims (3)

[Claims] (1) An airlift having an annular chamber (3) formed around a drill pipe (1), connected to the cavity thereof and connected to a pipe (2) for supplying compressed air via a check valve (4). The check valve (4) is provided around the drill pipe (1) and is coaxial therewith, and its inner surface connects the upper part of the large diameter and the lower part of the small diameter to the drill pipe (1) and the radial end ( A plunger (12) having a body (7) formed by a cylindrical sleeve (8) having similar to 9) and located in the body (7)
The lower part (13
) and an upper part (14) of small diameter forming a chamber (16, 17) of variable volume in the body (7) which is opened through openings (18, 19) in the radial ends of the body (7). The lower part (10) of the inner surface of the cylindrical sleeve (8) communicates with the pipe (2) supplying compressed air and through a passageway (20) made in the plunger (12).
) forms an annular cavity (21) of variable volume with the outer surface of the upper part (14) of the plunger (12) and communicates with the space behind the pipe through a radial opening (22) in the cylindrical sleeve (8). The communicating plunger (12) is moved downwardly to connect the inner cylindrical surface of the plunger (12) with the drill pipe (12).
) is provided above the drill pipe (1) and the plunger (12) during the downward movement of the latter. communicating with a variable volume chamber (16);
An air lift characterized by: (2) The radial opening (25) and the annular hole (26) are connected to each other from the inside, and the variable volume chamber (16) above the plunger (12) and the plunger (12) are connected to each other from the inside.
) communicating with an annular chamber (3) provided in the upper part of the cylindrical wall (12a), the annular hole (26) with an elastic ring (27) has a radial shape when the plunger (12) is located below it. Air lift according to claim 1, characterized in that it overlaps the opening (25). (3) an annular hole (28) with a split ring spring (28) adapted to act on the lower part of the inner surface of the cylindrical sleeve to fix the plunger (12) in its lower position;
Air lift according to claim 1, characterized in that the plunger (12) is provided in the upper part of the outer cylindrical wall of the plunger (12).