FI76865C - FOERFARANDE OCH ANORDNING FOER BORRNING AV DJUPA HAOL I BERG ELLER LIKNANDE. - Google Patents

Abstract

Method and apparatus for drilling deep holes in the rock or the like. The apparatus is adapted to be attached to the end of a drill string (1) and be sunk to the bottom of the bore hole (27). The apparatus comprises a pilot control unit (B), a hydraulic engine (12), a hydraulic pump (16), and impact apparatus (21) and a drill bit (23). Drilling mud which is fed down through the drill string to flash up the cuttings drives the hydraulic engine which is of a robust construction and will withstand the abrasive drilling mud. The output shaft (15) of the engine drives the hydraulic pump which pumps high grade hydraulic fluid to the impact apparatus which is a hydraulically driven hammer rock drill of known construction. The impact piston strikes against the drill bit. The whole apparatus is rotated by means of a rotary machine placed on the ground level. Due to the pilot control unit (B) the apparatus only has to carry its own dead weight and openings and valves provide a bypass and stopping, respectively, of the drilling mud.

Description

1 76865

Method and apparatus for drilling deep holes in rock or similar soil

TECHNICAL FIELD The present invention relates to a method and a hydraulic immersion rock drill for drilling deep and large holes in rock and solid earth.

Previous structures

Today, the so-called drilling of holes of the above-mentioned type is generally used. drilling, which means that the specially shaped drill bit is pressed simultaneously by rotating it into the ground. Because the drill bit has different parts, the rock or earth material is crushed into small pieces or particles. The drill bit is usually attached to a tubular shank with a diameter smaller than the diameter of the drill bit. A machine unit placed on the ground rotates the drill arm. This machine also has drill arm supports. The rock and earth material (called drilling waste) 20 ground by the drill bit is obtained from a borehole on the ground with a rinsing water or a special rinsing fluid called a drilling slurry. Flushing takes place by pressing the flushing fluid with a pump through the hole in the middle of the drill bit and the flushing holes in the drill bit at the bottom of the borehole, after which the drilling slurry rises to the ground outside the drill bit to remove drilling debris from the borehole. On the ground, most of the drilling waste is separated from the drilling sludge, e.g. in settling ponds, after which the rinsing liquid is pumped down into the hole again along the drill shank. In addition, a motor-assisted drilling method is known. The motor is then lowered into the borehole and attached to the lower end of the drill arm, which does not rotate. The direct driving force of the motor is the drilling mud.

The drilling described above is mainly used for soft sedimentary rock types. However, when drilling into a harder, crystalline rock type, this method becomes expensive because the drilling speed is very low and the drill 2 76365 blade wears a lot. A completely different drilling method is therefore used for such a rock type. It is called hammer drilling, which means that the impactor is struck at a rapid pace on the drill shank and / or the drill bit while the drill shank rotates simultaneously.

In this case, the machines used are usually driven by compressed air, i.e. the percussion piston is driven by compressed air, which usually also performs the rinsing of drilling debris. When drilling deeper and larger holes (up to 200 m), this method uses a so-called countersunk hammer, which means that the hammer and its percussion piston are attached to a tubular drill shank and lowered into the borehole by a rotating machine, which is basically similar in construction to drilling. described above.

In hammer drilling, compressed air is obtained from a compressed air compressor on the ground and is blown through the drill shank, thereby using an impact piston. The percussion piston, in turn, strikes the drill bit, after which compressed air flushes 20 drilling debris to the ground outside the drill shank. However, one disadvantage of this method is its limited deep drilling power. The method, on the other hand, is considerably faster than drilling, especially in hard rock.

In recent years, hydraulic hammer-25 drills have been developed that differ from pneumatic hammer drills in principle in that the percussion piston operates on high-pressure hydraulic oil. The drilling debris is flushed out separately with compressed air or drilling slurry. Until now, such hydraulic hammer opo-30 machines have only existed as so-called "surface machines", which means that the drill hammer machine operates in an above-ground machine unit. As a result, these machines have limited capacity when it comes to drilling deep and large holes. In each case, their drilling power with the same energy consumption is 3,76865 significantly higher than that of pneumatic drills.

Therefore, a submersible hydraulic hammer drill is required for high speed drilling of deep and large holes. However, this has not been possible so far, because the long pressure fluid lines going to the hammer rock drilling machine cause excessive pressure losses in deep holes.

As already mentioned, drilling debris must be removed from the borehole. This is always done in deep holes by means of flushing-10 slurry because the hydrostatic pressure in the hole is too high for compressed air. Drilling slurry could potentially be used to power a hydraulic hammer drill, but experts in the field believe that this is not feasible in practice. However, no matter how well the drilling mud has been allowed to settle before it is recycled, it always has a lot of sand and abrasive particles that will soon wear out the valve mechanism of the hammer drill. Pure 20 hydraulic oil must be used in such a hammer drill. Especially when using a hammer drill at high pressures, e.g. 150 bar, the hydraulic oil must be of very high quality.

Structure required by the invention

More specifically, the invention relates to a method for drilling deep holes in rock or similar soil, the hole being drilled with a drill bit attached to one end of the drill shank and drilling debris leaving the borehole by drilling slurry fed down the drill bit and flushed through the drill bit. and is squeezed out of the borehole using the energy of the drilling slurry in part as a driving force for a hydraulic motor located in the borehole near the drill bit, characterized in that the hydraulic motor output shaft is driven by a pressure fluid 35 percussion device applying numerous strokes to the drill bit. hammer drilling.

4,76865

When the impactor is pressurized, the motor output shaft is capable of operating a hydraulic pump that supplies high pressure fluid to the impactor. The pressure fluid is then in a closed circuit and a very clean and high-quality hydraulic oil can thus be used to ensure safe operation.

The submerged hammer drill according to the invention is rotated by a machine unit placed on the ground. The power take-off shaft of the hydraulic motor can also rotate the drill bit.

It is preferred that the drill bit is subjected only to the weight of the hydraulic motor and the percussion device and that it is independent of the length of the drill shank fed into the borehole, the feed being then easily provided by servo control.

The present invention also relates to an apparatus for applying the hammer drilling method 15 described above for drilling deep holes in rock or similar soil, the apparatus having a drill bit attached to the end of the drill bit as the drilling slurry passes drilling debris generated by drilling the hole through the drill bit and a hydraulic motor. which is driven by part of the energy of the drilling rig and which is located close to the drill bit. The device is characterized in that the impactor is driven by the output shaft of the hydraulic motor and impacts impacts on the drill bit.

25 Brief Description of the Drawings

The invention will now be described in detail with reference to the accompanying drawings, in which Figure 1 is a longitudinal section of a structure according to the invention and Figures 2-7 are cross-sections of the structure of Figure 1 lines II-II, III-III, IV-IV, VV, VI-VI and VII-VII.

Best mode for carrying out the invention and suitability for industrial use

The device mainly comprises seven interconnected or integrally connected units, which are indicated in Fig. 1 by the letters A-G.

5,76865

Unit A comprises a tubular drill shank of a known structure, which consists of separate parts connected to each other by conical threaded connections and extends to the ground. The drill shank is dimensioned so that it can withstand, in addition to torque and axial forces, a relatively high internal hydraulic pressure from the drilling mud.

Unit B comprises a feed or servo control device with which the drill bit is pressed with a suitable force into the bottom of the bore 10.

Unit C comprises a hydraulic motor already known in construction, which can be operated with the pressure energy of the drilling mud and which lasts a satisfactorily long time in use. This drilling rig may be water or other drilling mud 15 or a liquid and contains soil particles. The length of the hydraulic motor is large compared to its diameter.

Unit D comprises a hydraulic pump already known in construction, which is, however, a special construction. The hydraulic pump transfers pure hydraulic oil at high pressure.

Unit E comprises an oil tank with an oil filter, the length of which is large in relation to its diameter. The walls of the tank have channels for drilling mud and hydraulic oil.

Unit F comprises a pressure-driven hammer rock-25 drilling machine, the operating principle of the impact mechanism of which does not differ from the already known structures. In this case, the hammer-rock drilling machine is designed to act as an immersion drilling machine in a borehole, which is why it is e.g. equipped with drilling slurry flushing channels and a connector for transmitting torque, axial forces and shocks directly to the drill bit.

Unit G comprises a drill bit and carbide parts or pins of known construction, as well as drilling mud flushing channels.

The device according to the invention comprises a drill shank 1, which already consists of several interconnected drill shank parts.

6 76365

The drill shank 1 acts as a connecting part to the ground surface. The control unit (B) is connected to the drill shank and comprises an upper part 2, a cylindrical tube 3 and a lower part 4, which are connected to each other by threaded connections. The lower part of the cylindrical tube 3 has four openings 5 at a certain distance from each other in the circumferential direction 5. The lower part 4 has a square channel 6. The piston 7 is placed in a sealed structure in the cylindrical tube 3 and moves therein. The piston is attached to the piston rod 8, which is tubular in shape and has a rectangular outer structure. The stem 8 of the piston 10 moves with a small clearance or freely in the square channel 6 of the subunit 4. At the top of the piston rod there is a valve mechanism 9 comprising a cylindrical tube provided with a valve opening 11. This cylindrical tube is closed at its upper end and fits tightly into the cylindrical hole 11 of the upper part 2.

The drilling mud is pressed through the drill pipe 1 and its direction is shown in Fig. 1 by arrows illustrated by a solid line. Drilling sludge usually flows through the valve openings 10 and the piston rod 8, which is hollow, as well as the hydraulic motor 12. At the same time, the drilling slurry compresses the 20 pistons 7 downwards because the slurry pressure is lower in the cylindrical tube 3 below the piston 7, which space communicates with the borehole outside the cylindrical tube.

The hydraulic motor 12 has an inlet 13 and an outlet 14 for drilling mud. In addition, it has an output shaft 25 15 which rotates as the drilling mud flows through the motor.

The motor is already known per se, so it will not be described in more detail here. Any engine that is not damaged in a short time can be used with the drilling slurry.

The output shaft 15 of the hydraulic motor is connected to the input shaft 17 of the hydraulic pump 16. As the drilling slurry enters the hydraulic motor, this and the hydraulic pump start to rotate, which means that the hydraulic pump transfers high pressure hydraulic oil (15-20 MPa) to the damping accumulator 19. The hydraulic oil is further transferred to the sliding mechanism 20 of the hammer drill 7 76365, due to the structure of which the percussion piston 21 makes a rapid reciprocating movement. The lower end of the percussion piston 21 applies impacts to the connector 2 to which the drill bit 23 is threadedly attached. The impact from the impact piston is thus transferred to the blade of the drill 5, which crushes the earth and stone material at the bottom of the borehole. The hydraulic oil returns from the slide mechanism 20 to the oil tank 24 and from there on to the pressure fluid pump 16. The trajectory of the hydraulic oil is shown by the dotted arrows in Figure 1.

From the hydraulic motor 16, the drilling slurry passes through the channels 10 26 past the oil tank 24 and the hammer drill 18 to the connector 22 and then out through the flushing hole 25 in the drill bit 23. In this way, the bottom of the borehole is flushed with crushed material (drilling waste) which moves up with the drilling slurry on the ul-15 side of the device between the device and the borehole wall 27 and enters the ground where the drilling slurry is collected in separate basins. In them, most of the drilling waste is separated from the drilling slurry, which is then re-pumped down through the drill shank.

The torque of the ground-mounted drive (not shown in the figures) is transmitted through the drill shank 1 and the control unit (B) along the square channel 6 and likewise along the square piston rod 8 to other closely connected units C-F. From the hammer rock drill bit (F), the torque is transferred to the connector and the drill bit 23 because the connector has longitudinal grooves 28.

The operation of the device according to the invention is as follows.

At the start of drilling, the device is connected by threaded connections to a drive machine placed on the ground, after which the device is lowered so far into the borehole that the drill bit touches the bottom of the borehole. When the drill arm 1 is continuously lowered, the upper part 2 moves in the direction of the valve mechanism 9. The cylindrical part outside this mechanism protrudes with a suitable clearance into the upper cylindrical holes 1 of the upper unit 35 and is operatively connected to them. In this way, the inner channel of the drill shank, i.e. the cylindrical hole 11, is sealed so that the drilling mud cannot pass further through the piston rod 8. Thereafter, the drill arm 1 is slightly raised so that the cylindrical hole 11 of the upper unit appears at the upper edge of the valve mechanism 9, whereby the drilling slurry 5 can move freely. At the same time, the drive machine on the ground starts to rotate the drill arm and with it also the device according to the invention and starts the pump of the drilling mud placed on the ground. The hydraulic motor and pump then start the percussion piston and the hammer-10 rock drill moves downwards, thereby crushing the soil or rock material. The drill shank 1, the upper unit 2 and the cylindrical tube 3 rotate without moving vertically. The supply pressure to the drill bit 23 consists only of the weight of the units C-G, the piston 7 and the piston rod 8, and the hydraulic control pressure applied to the upper part of the piston 7.

When the drill bit and with it also the piston 7 have descended so deep into the borehole that the piston has passed the openings 5 on the side of the cylindrical tube 3, the drilling mud 20 flows out through these openings and further to the ground outside the device. The hydraulic motor 12 and with it the impact piston 21 stop, whereby the back pressure of the drilling slurry decreases due to the lower flow resistance, because the slurry does not have to pass through the hydraulic motor 12. This can be determined, for example, by a pressure gauge of the pump on the ground. The drill shank is then lowered again into the borehole by means of an above-ground drive machine. When the drill bit is at the bottom of the borehole, the piston 7 again covers the openings on the side of the cylindrical tube 3 so that the drilling mud 30 can pass through the piston rod 8 to the hydraulic motor 12 and the percussion piston begins to align again with the percussion and connector and the drill bit. When the drill shank has lowered so low that the valve mechanism 9 seals the cylindrical hole 11 in the upper unit 2, the fluid pressure 35 of the drilling slurry rises momentarily. In this case, the drill shank 1 rises slightly so that the drilling slurry channel becomes free, leaving the drill shank stationary vertically and rotating only when the drill bit and with it the piston 7 come below the openings 5 again and the working cycle is repeated.

5 Gradually lowering the drill shank 1 into the borehole by a distance corresponding to the stroke of the piston can take place automatically, e.g. by means of a ground-based drive mechanism which performs vertical movements of the drill shank (feed unit). This mechanism can be used to lower the drill bit 10 when the fluid pressure in the drilling slurry drops momentarily and to stop the drill bit when the pressure momentarily increases relative to the preset values. The drill arm can also be fed downwards at a constant, pre-set speed, which can be changed by the detection signals of the above-mentioned device.

In this way, the device according to the invention provides a relatively constant and limited pressure on the drill bit when drilling, which is desirable e.g. to reduce the wear of the drill bit and to reduce the required torque-20. In addition, this prevents the percussion piston from impinging impacts on the drill bit when this is not at the bottom of the borehole, which is important to prevent damage to the drill bit.

In addition, the control device allows the drill shank to move vertically a certain distance during drilling if the drilling slurry pump is equipped with an overflow valve, whereby the slurry flows over the pump on the ground if the slurry pressure exceeds a preset value. This makes it possible, for example, for drilling to be carried out with a drilling machine mounted on a drilling rig which moves vertically in a wave.

A structure according to the invention has been described above. Within the scope of the invention, various changes can, of course, be made to the device described above and various structural modifications can also be made. For example, the pressure fluid pump can be of any of the already known pump types, e.g. diaphragm pump. Alternatively, the hydraulic motor and pump can be replaced by two mechanically connected pressurized fluid cylinders, one of which acts as a motor and is powered by the drilling slurry and the other by a pressurized fluid pump. When the ratio of the cross-sectional areas of the pressure fluid cylinders is chosen in a suitable manner, e.g. 1: 3, the desired pressure is obtained for the hydraulic oil. The sliding and valve mechanisms of the pressure fluid pistons can be connected to each other so that they move together.

The device according to the invention is intended for drilling very deep holes, e.g. for oil drilling. The daily operating costs of the oil drilling carried out by the method are very high. Therefore, the device according to the invention only needs to be designed in such a way that it can reliably drill one complete borehole, after which it can be scrapped. However, if the device stops or gets stuck while drilling the hole is only halfway, the cost of lifting the device and making an oblique hole to drill next to the jammed device becomes very high. Since the drilling speed of the device according to the invention is approximately twice the speed of already known oil drills, considerable savings are obtained when drilling deep holes, in particular in oil drilling at sea.

The invention described above thus relates to a method and apparatus for drilling holes in the ground or rock, the drilling device then comprising a dual function of feeding a pressurized hammer drill-30 to the bottom of the borehole and rinsing the crushed earth or rock material out of the borehole. According to the invention, it is now possible to drill holes to a depth of several hundred meters with a hammer drill, the percussion piston of which impacts impacts on the rotating drill bit 35. This in turn means that the drilling capacity (drilling speed) can be doubled compared to the currently known methods and in some cases even increased tenfold, e.g. depending on the hardness of the rock type to be drilled.

Claims (10)

12,768 65 A method for drilling deep holes in rock or similar soil, the hole being drilled with a drill bit attached to one end of the drill bit and drilling debris leaving the borehole by drilling slurry fed down the drill bit and rinsed out of the drill bit and extruded using the energy of the drilling slurry in part 10 as a driving force for a hydraulic motor (12) placed in a borehole near the drill bit (23), characterized in that the output shaft (15) of the hydraulic motor (12) is driven by a pressurized impact device applying numerous impacts to the drill bit. hammer drilling-15 sessa. A method according to claim 1, characterized in that the output shaft (15) of the hydraulic motor (12) drives a pressure fluid pump (16) which pumps the pressure fluid to the pressure fluid-operated percussion piston (21) of the impactor. A method according to claim 2, characterized in that the pressure fluid pump (16) pumps high-pressure hydraulic oil to the pressure accumulator (19) to equalize the pressure, and that the drill bit is rotated by a ground motor, the rotational movement of which is transmitted to the drill bit. or alternatively, part of the energy of the hydraulic motor is used to rotate the drill bit in the borehole relative to the drill arm, which in this case is not rotated. Method according to one of the preceding claims, characterized in that the feed rate of the drill bit to the borehole is controlled by the drilling speed of the drill bit, the drill bit being mainly subjected to the weight of the hydraulic motor (12) and the impactor and possibly the pressure fluid pump and associated accumulator. 13 7 6 3 6 5 and that the impactor will not be able to strike the drill bit if the blade is not against the bottom of the borehole. A device for drilling deep holes in rock or similar soil, having a drill bit (23) attached to the end of the drill bit (1) as drilling slurry passes drilling debris generated during drilling through the drill bit and a hydraulic motor (12) driven by is part of the energy of the drilling device and is located close to the drill bit (23), characterized in that the impact device (21) is driven by the output shaft (15) of the hydraulic motor (12) and impacts impacts on the drill bit (23). Device according to Claim 5, characterized in that the hydraulic motor (12) is intended to drive a pressure fluid pump (16) which pumps high-pressure fluid 15 into an impact device (21) which is a pressure fluid-powered hammer drill. Device according to Claim 6, characterized in that the pressure accumulator (19) is connected to the discharge shaft (15) of the pressure fluid pump (16) for equalizing the hydraulic oil pressure 20, and that a ground-mounted device for rotating the drill arm and then the drill blade or alternatively the output shaft of a hydraulic motor, is arranged to rotate a rotating device belonging to the device according to the invention for rotating the drill bit to the non-rotating drill arm. Device according to one of Claims 5, 6 or 7, characterized in that it has a control unit (B) which, when drilling, loads the drill bit only by the weight of the hydraulic motor (12) and the impactor and possibly a pressure pump comprising 30 accumulators and prevents the impactor from striking the drill bit. , if this is not against the bottom of the borehole. Device according to Claim 3, characterized in that the control unit (B) makes it possible for the drill shank to move vertically during drilling without this having a significant effect on the load on the drill bit. 14 76365 Device according to Claim 8 or 9, characterized in that the control unit (B) is arranged to feed the drill arm (1) downwards at a speed which depends on the speed at which the drill bit 5 protrudes downwards during this downward feeding movement periodically and / or continuously. . is 7 6 8 6 5