RU2067148C1 - Circular air hammer - Google Patents

Abstract

FIELD: mining, particular, devices for hole drilling applicable in mining, hydrogeology and geological prospecting. SUBSTANCE: circular air hammer includes percussive mechanism with exhaust channel towards hole bottom, drilling cuttings transportation pipe, and drilling tool with central channel for receiving drilling cuttings and having receiving and mixing chambers separated by partition with central hole. Diameter of partition central hole, inner diameter of drilling cuttings transportation pipe and parameters of mixing chamber are taken from the relations d_n≅ d_t = (0.4-0.5)D, L= (1.2-1.5)D, where d_n is diameter of partition central hole; d_t is inner diameter of drilling cuttings transportation pipe; D and L are diameter and length of mixing chamber. Besides, mixing chamber is communicated with exhaust passage by means of channels, and partition has radial recesses also communicated with exhaust passage by means of channels. EFFECT: extended technological capabilities due to drilling, practically, any type of rocks under normal technogenic conditions. 3 cl, 3 dwg

Description

 The invention relates to a device for drilling wells and may find application in the mining industry, hydrogeology and exploration.

 Known annular hammer (ed. St. N 1370218), designed for drilling wells mainly in permafrost, including a housing, step hammer with a through axial channel, an annular rock cutting tool and a slam-transfer pipe that make up the sludge receiving channel.

 The technological ability of this hammer is limited by the permafrost drilling. During drilling of easily destructible plastic rocks, sludge receiving channel is sludged.

 Closest to the technical nature of the present invention is an annular hammer (ed. St. N 1671836), comprising a housing, a step drummer with a through axial channel, an annular rock cutting tool and a central slurry transfer pipe constituting a sludge receiving channel.

 The well-known annular hammer is designed for drilling permafrost, that technological ability is limited and when drilling soft, moist plastic rocks, sludge receiving channel is sludged. A large mass of the destroyed rock does not have time to pass through the sludge receiving channel and further to the surface. The hammer exhaust sharply shuts off and its operation stops. In many cases (humidified clay rock), the effect of cleaning the sludge receiving channel is not achieved even with the so-called "flow rate", that is, when the hammer is separated from the face in order to purge its channels with main compressed air.

 The technical task of the invention is the expansion of the technological capabilities of the hammer by ensuring the drilling of almost any rock.

The problem is solved by the fact that the annular hammer includes a percussion mechanism with an exhaust path to the bottom, a slurry conveyor pipe and a drilling tool with a central slurry receiving channel, which is made with an intake and mixing chambers separated by a partition with a central hole, the diameter of the central opening of the partition and the inner diameter of the slurry transport pipes and parameters of the mixing chamber are selected from the ratios:
d _p ≅ d _t (0.4 0.5) D;
L (1.2 1.5) D,
where d _{n the} diameter of the Central hole of the septum;
d _t inner diameter of the sludge transport pipe;
D and L are the diameter and length of the mixing chamber.

 In addition, the mixing chamber is connected by channels to the exhaust tract, and the partition is provided with radial grooves, also connected by channels to the exhaust tract.

 In order to expand the technological capabilities of annular hammers, which could drill not only hard rocks, but also wells in soft and plastic rocks, it is necessary to ensure good cleaning of the annular face and effective removal of the destroyed rock to the surface. In this regard, the sludge receiving channel in the drilling tool is made of two chambers: intake and mixing, separated by a partition with a central hole, which calibrates the sludge into fractions and ensures its free passage into the sludge transport pipe. Cleaning of the bottom and removal of sludge to the surface provides pressure exhaled compressed air. Therefore, channels are made in the body of the drilling tool, directing compressed air to the face and into the mixing chamber.

To ensure effective removal of sludge to the surface, the parameters of the sludge receiving channel and sludge transport pipe must satisfy the ratios indicated above. In particular, the diameter of the central opening of the partition d _p must be less than or equal to the inner diameter of the sludge transport pipe d _t . This ratio is determined by the fact that the hole d _p in the partition acts as a calibrator and sludge enters the mixing chamber, the particle sizes of which do not exceed the dimensions of the inner diameter of the sludge transport pipe d _t . In addition, the diameter of the mixing chamber should be two or more times greater than the inner diameter of the sludge conveyor pipe d _t , and the length of the mixing chamber should be 1.2 to 1.5 times its diameter. These ratios are determined by the fact that when drilling soft plastic rocks, sludge particles that are longer than the diameter d _{t of the} sludge transport pipe can pass through the hole d _{p of the} partition into the mixing chamber.

 Considering that the drilling tool rotates together with a pneumatic impact tool and the exhaled compressed air is constantly fed into the mixing chamber, this chamber additionally destroys the sludge to a size that allows it to freely pass through the slurry transport pipe and further to the surface.

 New design solutions, together with the well-known ones, made it possible to develop an annular hammer, designed for drilling in any technogenic conditions, that is, for drilling hard rocks and various soils.

 In FIG. 1 shows a longitudinal section through the bottom of an annular hammer with a solid drilling tool; in FIG. 2 a similar section with a compound drilling tool; in FIG. 3 view of the hammer from the downhole side.

An annular hammer consists of a housing 1, an adapter 2, an annular hammer 3 with a through axial channel, inside of which there is a sludge conveyor pipe 4 with an inner diameter d _t that enters the lower end into the central channel 5 of the shank 6, which is connected to the housing 1 by splines 7 through a nut 8 A drilling tool 9 is attached to the lower end of the shank 6 by a thread, which in FIG. 1 is shown as one piece, and in FIG. 2 compound.

The composite drilling tool comprises a housing 10 and a removable crown 11. Such a tool is used in hammers designed for drilling large diameter wells of the order of 300 mm. In the drilling tool 9 is placed a Central sludge receiving channel, which consists of a intake 12 and a mixing chamber 13, separated by a partition 14 with a Central hole with a diameter of d _n . The parameters of the mixing chamber include a diameter D and a length L. In the body of the drilling tool 9, channels 15 of the exhaust duct are made, which is connected by channels 16 to the mixing chamber 13. The partition 14 is provided with radial grooves 17 connected by channels 18 to the channels of the exhaust tract (Fig. 3) . The bottomhole and spherical parts of the intake 12 of the chamber are equipped with carbide inserts 19. A packer 20 is installed on the housing 1.

 Ring hammer works as follows.

Compressed air is supplied to the hammer adapter 2 through the drill string, under the influence of which the hammer 3 reciprocates and strikes the shank 6 of the drilling tool 9. Carbide inserts 19 are introduced into the rock. The destroyed rock, accumulating in the intake chamber 12, under the pressure of the expelled air through the holes d _{n of the} partition 14 and the radial grooves 17 enters the mixing chamber 15. The size of the particles of rock entering the mixing chamber 15 is limited by the size of the hole d _{n of the} partition 14 and the dimensions of the radial grooves 17. Otherwise, these particles are additionally crushed in the intake chamber 12. When drilling viscous, plastic rocks, not only particles, but also core-shaped columns, the sizes of which Line larger than the diameter d _t shlamotransportnoy pipe. In this case, the columns during the rotation of the hammer and the impact of the flow of exhaled air entering through the channels 15, 16 and 18 will be destroyed in the mixing chamber 13 and sent further to the sludge transport pipe 4. The packer 20 seals the space between the housing 1 and the well and all the destroyed rock, collected in the intake chamber 12, sent to the mixing chamber and brought to the surface, thereby providing 100-th output of the rock and improves the quality of testing during exploration.

 The proposed annular hammer is a universal drilling machine designed for drilling wells in sandy and clayey rocks, silty sediments, zones of cementless sands and other rocks prone to collapse and can be widely used in hydrogeology and exploration when it is necessary to drill wells from a zero mark. YYY2

Claims (3)

1. An annular hammer, including a percussion mechanism with an exhaust path to the bottom, a slurry transfer pipe and a drilling tool with a central sludge receiving channel, characterized in that the sludge receiving channel is made with an intake and mixing chambers separated by a partition with a central hole, the diameter of the central opening of the partition, the inner the diameter of the sludge conveyor pipe and the parameters of the mixing chamber are selected from the relations
d _p ≅d _t = (0.4-0.5) D;
L = (1.2-0.4) D,
where d _{p the} diameter of the Central hole of the septum;
d _t inner diameter of the sludge transport pipe;
D and L are the diameter and length of the mixing chamber.  2. The hammer according to claim 1, characterized in that the mixing chamber is connected by channels to the exhaust tract.  3. The hammer according to claim 1, characterized in that the partition is provided with radial grooves connected by channels to the exhaust tract.

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