RU28180U1 - Pneumatic Impactor - Google Patents

Description

IPC: E21B49 / 02 GOlNl / 08

Pneumatic Impactor

The utility model relates to devices designed for drilling shallow (up to 30 m) wells mainly in shallow and transitional (transit) zones of the continental shelf for the purpose of engineering and geological surveys of sites for the construction of oil and gas complexes and port facilities, exploration of marine growing minerals, hydrogeological surveys . The difficulty in drilling in the zone of extreme shallow water (sea depth 0.5 - 1.5 m) lies in the fact that the work is carried out from small shallow-sitting pontoons, the load-carrying capacity of which often does not allow the use of well-developed technology for shallow offshore drilling, for example, shock-rope drilling with leading casing plugging . Under these conditions, the use of alternative drilling methods is promising, in particular, using the energy of compressed air.

core pipe, a hammer with a striker making reciprocating movements, and a damping device that prevents the hammer from being thrown up when the striker moves down. Compressed air of relatively low pressure (6 atm.), But with a high flow rate (5), is used to drive pneumodump. Exhaust air is emitted into the well, and from it into the atmosphere. In this case, the wall of the well was compacted and maintained stability for a long time (see Alexandrov G.S. et al. Results of drilling wells with the integrated use of compressed air. - Express information. VIEMS. Technical and technological geological exploration; org. production, 1976, p. 28-34).

A disadvantage of the known soil carrier is the low reliability of its pneumatic impact mechanism in waterlogged wells due to backpressure, which creates water filling the well.

Designs using high pressure air (50-100 atm.) To drive the shock mechanism are deprived of this drawback. The back pressure of the medium where the exhaust air is discharged significantly less affects their performance.

The closest in technical essence to the proposed one is a pneumatic shock soil carrier (adopted as a prototype), containing a core pipe and a shock mechanism in the form of a pneumatic chamber with a piston installed in it for periodic air inlet from the pneumatic chamber exhaust port into a nozzle made in the form of an expanding cone (ed. St. USSR No. 608920, publ. 30.05.78). The introduction of the soil carrier occurs due to pulses of reactive force (shock) that occur when opening the pneumatic chamber. The magnitude of the reactive force is proportional to the density of the mixture ejected from the nozzle and the square of the velocity of this ejection. When working in conditions when the nozzle is under water, the effectiveness of the known soil-carrying tank is maximized due to the discharge of water filling the nozzle during a pause between air exhausts from the pneumatic chamber. The reactive force, and, consequently, the length of the selected column, decreases sharply when the nozzle is at the water level and only air is thrown out, whose density is many times less than the density of water.

The proposed utility model allows to increase the length of the selected soil column.

The technical result is achieved by the fact that in a pneumatic shock soil carrier containing a core pipe and a percussion mechanism in the form of a pneumatic chamber with a piston installed in it for periodically raising compressed air from

the pneumatic chamber exhaust hole into the nozzle, made in the form of an expanding cone, the repeating shape of its expanding cone of the strikers connected to the core pipe and installed with the possibility of longitudinal movement inside the perforated glass attached to the nozzle is installed in the nozzle.

The proposed utility model also allows to improve the penetration of soil in flooded sand and gravel deposits. This is achieved by the fact that a piston rigidly connected to the perforated glass is installed in the core pipe, equipped with a check valve that allows water to pass from the under-root cavity of the core pipe to the over-piston.

The drawing shows a diagram of pneumatic shock soil carrier in a straight-through version (Fig. 1) and in a vacuum version (Fig. 2).

The pneumatic shock soil carrier comprises a core pipe 1 and a percussion mechanism in the form of a pneumatic chamber 2 with a piston 3 installed therein for periodically releasing compressed air from the exhaust opening 4 into the nozzle 5, made in the form of a expanding cone. The nozzle has a repeating shape of its expanding cone of the hammer 6, connected to the core pipe 1. The hammer 6 is mounted with the possibility of longitudinal movement inside the perforated glass 7, attached to the nozzle 5.

In the direct-flow execution of the soil carrier (Fig. 1), the core pipe 1 is equipped with a check valve 8, which passes water from the core-receiving cavity through openings 9 into the well. In the vacuum version of the soil pump (Fig. 2), a piston 10 is installed in the core pipe 1, which is rigidly connected to the perforated glass 7 with studs 11. The piston 10 is equipped with a check valve 12, which passes water from the undergrowth cavity of the core tube into the over-piston.

The piston 3 is made three-stage with different diameters of the stages: the middle stage 13 is larger than the brake stage 14, and that, in turn, is larger than the upper stage 15. Compressed air is supplied through the hose 16 to the channel 17, which has an exit to the cavity of the pneumatic chamber 2, limited by the middle 13 and brake 14 steps of the piston 3. To increase the inert mass of the pneumatic chamber 2, a load 18 is attached to it, connected to the cable 19 of the pontoon winch.

Works pneumatic impact as follows. For the selection of soft sludge OB and clay use pneumatic shock soil carrier in direct-flow execution (Fig. 1). Gruntonos on the cable 19 is lowered into the well and compressed air is supplied through the hose 16 and channel 17 into the cavity of the pneumatic chamber 2, limited by the middle 13 and brake 14 steps of the piston 3. Due to the small difference in the diameters of these steps, the piston 3

moves downward, closing the hole 4 with the exhaust stage 15. Compressed air fills the working chamber of the pneumatic chamber 2, increasing the pressure in it to the value of self-suspension, which is determined by the difference between the diameters of the brake 14 and the exhaust 15 stages of the piston 3. Moving to the side of the larger stage, the piston 3 opens the exhaust hole 4. The pressure of the compressed air acting on the outer torp of the exhaust stage 15, sharply throws the piston 3 to its highest position (shown in the diagram), completely opening the exhaust hole 4. Expanding, compressed air pushes the striker 6 from the nozzle 5, the crushing core barrel 1 into the soil and simultaneously tossing pneumatic chamber 2 up. The amount of movement of the pneumatic chamber is limited by its own mass, as well as the mass of the cargo 18 attached to it. Exhaust air leaves through the holes in the walls of the perforated cup 7 into the well, and then into the atmosphere. The pneumatic chamber 2, under its own weight and load 18, goes down, again covering the nozzle 5 of the strikers with the cone 6. The piston 3, under the action of the pressure difference on its middle 13 and brake stage 14, goes down, closing the exhaust hole 4. The cycle repeats. A column of soil entering the pipe pushes water through openings 9 into the well. When the soil column is torn from the formation and raised to the surface, the valve 8 closes the holes 9, helping to hold the soil in the core pipe 1.

For the selection of dense sand and gravel deposits using pneumatic shock soil-carrier in a vacuum version (Fig. 2). When exhausts of compressed air from the pneumatic chamber 2, the piston 10 moves up, and the core pipe 1 - down. As a result of these mutually opposite movements, a vacuum is generated under the piston 10. Water and exhaust compressed air filling the well, trying to fill the vacuum above the selected column, create an upward filtration flow of pore water, weakening the soil in the core pipe and under its tip to a quicksand. Under these conditions, the resistance to the introduction of the soil carrier decreases sharply, its penetration improves. In addition, the backwash of the well helps to clear the annular gap between the soil pump and the wall of the well from soil particles, reducing the risk of jamming of the soil pump. During a pause between air exhausts, the piston 10 lowers downward, squeezing water through the check valve 12 into the over-piston cavity, and from there, with the next exhaust, through the openings 9, the water is pushed into the well.

Due to the design differences of the proposed pneumatic shock soil carrier, the following technical and economic result is achieved:

1. The transformation of the soil carrier from a jet to a shooter allows you to increase the length of the selected column in cases when there is either no water in the well or its level is below the exhaust nozzle of the non-camera.

2.Using the mutually opposite movement of the pneumatic chamber and the core pipe to create a vacuum over the selected soil column allows to improve the penetration of the soil carrier in flooded sand and gravel deposits. Less compressed air and working time are required to select a column of a given length.

Claims (2)

1. A pneumatic shock soil carrier containing a core pipe and a percussion mechanism in the form of a pneumatic chamber with a piston installed therein for periodically releasing compressed air from the pneumatic chamber’s exhaust outlet into a nozzle made in the form of an expanding cone, characterized in that the nozzle has a repeating shape of its expanding cone of the strikers connected to the core tube and mounted with the possibility of longitudinal movement inside the perforated glass attached to the nozzle. 2. The pneumatic shock soil carrier according to claim 1, characterized in that the piston is rigidly connected to the perforated nozzle in the core pipe and is equipped with a check valve that allows water to pass from the sub-piston cavity of the core pipe to the over-piston.