RU2640605C2 - Water thermodrill for drilling wells in ice bodies - Google Patents

Abstract

FIELD: machine engineering.

SUBSTANCE: device contains a hollow body in the form of a pipe, to the upper end of which is attached a drill hose, supplying a hot water to the body, a drill bit is attached to the lower end of the body. The drill bit consists of a tip and a bush. The tip has a small parabolic sharpening about one centimetre in length from the outside and a conical bore inside. The bush with an axial hole along its entire length has a conical groove outside at the bottom and a conical groove inside, on the outside of the conical surface of the bush the rectangular grooves are cut in the form of thread. The tip is attached to the body by means of a thread. The bush is mounted coaxially in the tip. The conical surface of the bush enters the cone hole of the tip so that their ends are flush at the same level, while the grooves on the conical surface of the bush form channels for discharging water from the bit in the form of spread, swirling jets. The bush is pressed against the tip by means of a spring held in place by a nut screwed into the upper part of the tip and has a free move upward with increasing clearance between its outer conical surface and the inner conical surface of the tip.

EFFECT: sensitivity is increased to determine the position of the boundaries and the dimensions of voids in ice piles while maintaining a high drilling speed.

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Description

The invention relates to devices for thermal drilling of wells in ice and can be used to study glaciers and piles of sea ice - hummocks and ham. A known method for determining the structure of hummocks and hammers, the properties of ice and the boundary of ice and soil by thermal drilling of wells [4].

It is known that core and coreless drilling with electrothermoburas developed in the Arctic and Antarctic Research Institute [1, 2], which have been used to study glaciers and sea ice since 1970. The advantages of electrothermobuers are its relatively light weight, the ability to drill wells to the entire depth of hummocks, the ability to determine the size and location of voids in ice with high accuracy. The disadvantage is the low speed of drilling ice.

A device for water drilling of wells in ice [3] is known, which is a thermally insulated pipe through which hot water is delivered through a rubber hose to a bottomhole. Water melts the ice, and the pipe falls under the influence of its gravity. As it goes deeper into the ice, a pipe having a threaded connection builds up. The disadvantage of this device is the high water consumption and low productivity, because due to the free flow of hot water, a wide well is formed.

The closest adopted prototype is a water drill [5], in which hot water is supplied through a hose to the drill body and discharged through an opening in the nose of the drill bit, the hollow body of which is made in the form of a paraboloid. Such devices have been widely used in glacier research for drilling wells for various purposes. The figure 1 shows a diagram of a water drill. The device consists of a hollow body 1, a drill hose 2 is connected to its upper end, and a drill bit 3 is located at the lower end of the body. The advantage of this water thermal drill is its high drilling speed. The disadvantage is that when using it to study the internal structure of large ice formations, when the presence or absence of voids is determined by the speed of immersion of the drill, it is impossible to fix voids smaller than 10-15 cm, due to the large length of the parabolic crown of the thermal drill, on which the shell freezes when the drill leaves the void. Melting of the walls of the well continues with the hot parabolic part of the drill, and the movement of the drill slows down until it subsequently falls into the void or stops in the ice block located below. With small sizes of emptiness, the failure of the drill does not occur, and the presence of emptiness is not fixed. Moreover, during the hang of the drill, water flowing from the crown melts the block of ice located under the cavity, forming caverns in it.

The purpose of the invention is to increase the sensitivity when using a device for determining the position of the boundaries and sizes of voids in ice piles while maintaining a high drilling speed.

The technical result is achieved by reducing the parabolic part of the crown of the thermal drill to a length of about one centimeter, giving the optimum ratio of drilling speed and resolution of the thermal drill when fixing voids in ice, the additional release of a number of diverging swirling jets of water and the possibility of increasing the gap and, accordingly, the water flow for cleaning the channels from pollution.

Figure 2 shows a diagram of a drill bit of a thermal drill. The drill bit consists of a tip 4, an insert 5, a sleeve 6, a nut 7, a nozzle 8, rings 9 and 10 and a spring 11. The sleeve 6 contains a thread at the upper end for attachment to the drill body. At the lower end of the tip 4, a parabolic sharpening is made outside, forming a face, and a conical groove inside for installation in it and fixing the liner 5. The liner 5 has a conical shape on the outside and a conical shape on the inside with an axial hole in the upper part, the diameter of which is determined by the nozzle 8. On the outer conical surface of the liner 5, rectangular grooves are cut in the form of a thread with a large pitch. The liner 5 is installed in the tip 4 coaxially. A thread is made in the upper part of the sleeve 6 to install a nut 7, which fixes a spring 11 that presses the insert 5 against the inner conical surface of the tip 4 so that the ends of the tip 4 and the insert 5 are flush at the same level. In this case, the grooves on the conical surface of the insert 5 form channels for discharging water from the crown in the form of diverging swirling jets. Figure 3 illustrates the appearance of the threaded portion of the liner 5.

The operation of the device is as follows. The central jet of hot water and diverging swirling jets form an annular face in the ice, while the central part of the molten ice on the face in the form of a sharp protrusion falls into the conical cavity of the liner 5, where it is melted by a stream of water from the central nozzle hole 8. The diameter of the face is slightly larger than the diameter of the drill , which eliminates the hang of the drill when it leaves the dense ice in the cavity. In this case, there is no destruction by the water jets of ice located behind the cavity, and the drilling speed corresponds to the presence or absence of ice.

To quickly clean the grooves from accidental contamination, it is possible to increase the gap between the tip 4 and the insert 5. Under external force, the insert 5 is recessed inside the tip 4, the gap increases, and, accordingly, the flow rate increases through the crown, which flushes the grooves of the insert 5. After removal the force of the spring 11 returns the liner 5 into place.

Such a device was tested during hummock drilling, where its high efficiency and reliable operation were confirmed.

INFORMATION SOURCES

1. A.S. No. 350945, BI No. 27, publ. 11/13/72

2. A.S. No. 439601, BI No. 30, publ. 08/15/74

3. Astafyev V. N., Surkov G. A., Truskov P. A. Toros and the hamlets of the Sea of Okhotsk. - St. Petersburg: Press Weather, 1997. - 208 p.

4. Patent of Russia No. 2153070 dated July 20, 2000. Bulletin No. 20.

5. Taylor Ph. L. A Hot Water Drill for Temperate Ice. CRREL Special Report 84-34, 1984. p. 105-117.

Claims (2)

1. Device for drilling wells in ice, containing a hollow body in the form of a pipe, to the upper end of which is connected a drill hose that supplies hot water to the body, a drill bit is attached to the lower end of the body, characterized in that the drill bit consists of a tip and an insert: the tip has a small parabolic sharpening about one centimeter long on the outside and a conical bore inside, the liner with an axial hole along the entire length has a conical groove on the outside on the outside and a conical groove on the inside, on the outside to rectangular grooves in the form of a thread are cut into the liner surface, the tip is attached to the body with the help of the thread, the liner is aligned coaxially with the cone, the conical surface of the liner enters the cone hole of the tip so that their ends are flush at the same level, while the grooves on the conical the liner surfaces form channels for discharging water from the crown in the form of diverging swirling jets. 2. The device according to p. 1, characterized in that the liner is pressed against the tip by means of a spring held by a nut screwed into the upper part of the tip and has a free travel upward movement with an increase in the gap between its outer conical surface and the inner conical surface of the tip.

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