RU167571U1 - THERMAL ISOLATING DIRECTION OF A DRILL WELL - Google Patents

Abstract

A thermally insulating direction of a borehole is provided, comprising at least a pair of series-connected sections. Each of them has coaxially located inner and outer pipes with a space between them filled with thermal insulation. In the junction zone of the sections, the inner pipes protrude from the outer pipes and are connected to each other by an appropriate connection, and the cavity in the junction of the upper and lower sections between the outer pipes and the pipes of the upper and lower sections connected by a corresponding connection, are filled with thermal insulation and are covered by a shell from the outside tightened by clamps located along a helical line. In this case, the butt ligaments of the inner pipes between the adjacent ends of the sections are formed by joints that ensure their self-centering and self-fixation of the position relative to each other. Thus, the technical result of the claimed utility model is achieved, namely: ensuring accurate centering of the connection of the inner pipes to each other and centering in the borehole thermally insulating direction lowered into it.

Description

This utility model relates to devices for arranging wells in permafrost conditions (MMP) and is intended to prevent thawing of soils and to ensure a stable position of wellheads.

Currently, there are several technical solutions that prevent the thawing of permafrost. One of them is a thermally insulating casing (thermal case) or, for example, a thermally insulating direction of the “Jol” type (VF Buslaev, PS Bakhmetyev, SA Kane, VM Yudin. Well construction in the North: Monograph .-- Ukhta: Ural State Technical University, 2000 .-- pp. 169-170, Fig. 6.7). It is designed to prevent thawing of the surrounding frozen rocks and freezing of equipment during drilling. This well-known thermo-insulating direction is formed of two orders of 9 meter sections that are welded together. Each section contains internal and external coaxially installed pipes and thermal insulation placed between them.

This known thermally insulating direction has a significant drawback, namely, a large length, which makes it difficult to install such a device in the well. This is due to the fact that when lowering into the well a heat-insulating direction of such a length, it is difficult to center it along the depth of the well.

Known utility model "Thermal insulation direction" (Patent No. 74415, IPC ЕВВ 36/00, publ. 06/27/2008). It is intended for drilling wells in ice rocks. This known direction contains the upper and lower sections, each of which has an inner and outer coaxially arranged pipes and thermal insulation located between them. In the joint zone of the upper and lower sections, the inner pipes protrude from the outer pipes and are provided with flanges that form a collapsible connection. On the outside, the joint zone is covered by a shell, and the cavity between the shell and the inner pipe is filled with thermal insulation. The shell on the outside at its ends is clasped by clamps. Fasteners for temporarily fixing the ribs are made on the outer pipe of the lower part of the direction, which are used to support the lower section on the borehole walls during the installation of the thermally insulating direction. The ribs are installed before the lower section is lowered into the well. After assembling the thermally insulating direction, the ribs are removed.

This known thermal insulating direction has a significant drawback. It consists in the difficulty of centering the connection of the inner pipes to each other, which is due to the use of a flange connection, in which the flange at the lower end of the upper inner pipe can be made free. This provides him with an easy docking of his bolt holes with bolt holes of the flange of the upper end of the lower pipe, but does not guarantee accurate centering of the position of the connected pipes relative to each other and the exclusion of play between them. In addition, when concrete fills the space between the heat-insulating direction and the wells, the clamps on the shells create obstacles for the uniform distribution of concrete around the surface in the connection zone of the section inner pipes. As a result, tricky things may form in such places, which can reduce the reliability of the operation of the thermally insulating direction in the borehole.

Known utility model "Thermally insulating direction of the borehole" (Patent No. 158353, IPC ЕВВ 36/00, publ. 09/28/2015). It is made collapsible and consists of upper and lower sections, each of which contains an inner and outer pipe with heat insulation placed between them. In the joint zone of the sections, the inner pipes protrude from the outer pipes and are provided with interconnected flanges. Moreover, the number of sections can be two, three or more. Each section in the joint zone has the ends of the inner pipe protruding from the outer pipe, in which the lower end of the inner pipe of the upper section is connected to the upper end of the inner pipe of the lower section with a flange connection, and the cavity in the joint zone of the upper and lower sections between the outer pipes and connected between each other, by means of a flange connection, by the inner pipes of the upper and lower sections, is blocked by at least two heat-insulating shells or heat insulation. They are externally covered by a shell, which is externally clasped at its ends by clamps. On it, they form rims perpendicular to its surface. On the outer pipes of each of the lower sections, fasteners (not shown) for temporarily fixing the ribs to support the thermally insulating direction on the borehole walls during installation are installed.

This well-known technical solution is selected for the prototype, as it has the largest number of essential features that match the essential features of the claimed utility model. In addition, it belongs to the latest development of the insulating direction and is widely used in the construction of wells in permafrost conditions.

However, the prototype has a significant drawback, namely: it is difficult to center the connections of the inner pipes to each other, due to the use of a flange connection, in which one flange at the lower end of the upper inner pipe can be made free. This makes it difficult to align the bolt holes of one flange at one end of the inner pipe with the bolt holes of the other flange located at the other end of the other inner pipe. As a result, a backlash is possible in such a connection, which reduces the reliability of the operation of this direction in the borehole. In addition, when lowering such a thermally insulating direction into the borehole, it is difficult to center it relative to the borehole. Moreover, while filling concrete with the space between the heat-insulating direction and the borehole, the clamps, clutching shells create an obstacle for the even distribution of concrete and tricks can form under these clamps, which may decrease the reliability of the thermal-insulating direction over time.

The objective of this utility model is to improve the heat-insulating direction of the borehole by achieving the following technical result, namely, ensuring accurate centering of the connection of the inner pipes to each other and centering in the borehole of the thermally insulating direction that is lowered into it.

The problem is solved as follows. In the well-known heat-insulating direction of the borehole, containing at least a pair of series-connected sections, each of which has coaxially located inner and outer pipes with a space between them filled with thermal insulation, and in the joint zone of the sections, the inner pipes protrude from the outer pipes and are connected between themselves using the appropriate connection, while the cavity in the junction of the upper and lower sections between the outer pipes and connected by means of a corresponding pipe connection the upper and lower sections are filled with thermal insulation and covered with a shell covered by clamps on the outside, and fasteners for temporarily fixing ribs are installed on the outer pipes of each of the lower sections to support the thermally insulating direction on the borehole walls during installation, according to this utility model, butt joints of internal pipes between the adjacent ends of the sections are formed by compounds that ensure their self-centering and self-fixation of the position relative to each other, and the shell is pulled over the clamps extending beyond the diameter of the section, but not exceeding the gap between the section and the wall of the well, are laid on the shell along a helical line with the ability to perform the functions of a centralizer, connected sections when immersed in the well, and guides the distribution of concrete when pouring it into the space between the outer section wall and borehole wall.

Such a new technical solution, with its whole set of essential features, allows us to achieve the following technical result, namely, to center the position of the connected sections of the insulating direction and lower them into the borehole. This is achieved due to the fact that the butt ligaments of the inner pipes between the adjacent ends of the sections are formed by joints that ensure their self-centering and self-fixing position relative to each other. Moreover, such a butt joint of internal pipes can be achieved, for example, by using corresponding conical holes in the flange connection, corresponding gaskets that can be fixed on the flanges and uniformly seal this connection when pulling the flanges together. Corresponding catchers of the position of the flanges relative to each other can be used, and also a sleeve threaded connection or the like of another device can be used. In addition, the shell is tightened with clamps, forming rims on the surface of the shell that extend beyond the diameter of the outer section, but do not go beyond the gap between the section and the borehole wall. At the same time, the rims are laid on the shell along a helical line with the ability to perform the functions of a centralizer, connected sections when immersed in the well and serving as guides for the distribution of concrete when pouring it into the space between the outer wall of the section and the wall of the well. As a result, a spiral helix made of clamps evenly distributes the immersed heat-insulating direction along the borehole and, when pouring concrete between it and the borehole wall, evenly centers and distributes it around sections of the mentioned direction.

The applicant conducted a patent search, which showed that the proposed set of essential features for the claimed utility model was not found. Therefore, the claimed utility model can be considered new.

The practical application and technical essence of the claimed utility model is illustrated by the drawing (see. Fig.) And the following description.

The thermally insulating direction of the borehole contains at least a pair of series-connected sections 1 and 2. In principle, there may be more of these sections. Each section 1 and 2 has a coaxially located inner and outer pipes 3 and 4. The space between the pipes is filled with thermal insulation 5, for example, made of polyurethane foam (PUF). In the joint zone of sections 1 and 2, the inner pipes 3 protrude from the outer pipes 4 and are interconnected using the corresponding connection 6, which ensures self-centering and self-fixing of their position relative to each other. In essence, such a connection 6 can be achieved, for example, by using corresponding conical gaskets (not shown) in the flange connection, which can be connected to the flanges. Then these gaskets when compressing the flanges with each other will provide sealing of this connection of the inner pipes to each other. Corresponding catchers (not shown in the drawing) of the position of the flanges relative to each other can be used, and also a sleeve threaded connection or the like of another device (not shown) can be used. The joint zone between the outer pipes 4 is covered by a shell 7. The cavity between the shell 7 and the inner pipe 3 is filled with thermal insulation 8, for example, made of polyurethane foam or mineral wool or other similar material. The shell 7 itself is tightened with clamps 9 that extend beyond the diameter of the section 1 or 2, but do not go beyond the gap between the section and the borehole wall. These clamps 9 are laid on the shell 7 along a helix with the possibility of performing the functions of a centralizer of the connected sections 1 and 2 when they are immersed in the well. In fact, the clamps 9 form a helical line on the surface of the shell 7. To fix their position along the helix, spot welding is permissible in separate places with the outer wall of the section and shell 7. This increases the rigidity of the position of the clamps on the shell and they can also serve as a guide for the distribution of concrete (not shown) when pouring it into space between the outer wall of the section and the wall of the well. On the outer pipe of the lower part 3, fasteners (not shown in the drawing) are made, intended for temporary fixation of the ribs (not shown in the drawing).

The upper and lower sections 1 and 2 are prepared in the factory according to known technologies.

Before lowering the lower section 2 into the well, fasteners, which may be studs fixed in the wall of the outer pipe 3, install ribs (not shown in the drawing). When lowering into the well, the lower direction section rests on the walls of the well with the ribs. Then make installation (assembly) of the direction. The upper section is installed on the lower section, their internal pipes are connected, the joint zone is filled with a heat insulator and covered with a shell 7. After that, the ribs are removed from the fasteners and the direction is lowered to a predetermined depth. In this case, the clamps 9 on the shells 7 located along the helical line provide centering of the sections along the well, and then they allow evenly distributed concrete between the wall of the well and the sections to be distributed between them.

Through the proposed direction produce further drilling of wells.

Claims (1)

The thermally insulating direction of the borehole, containing at least a pair of series-connected sections, each of which has coaxially located inner and outer pipes with a space between them filled with thermal insulation, and in the joint zone of the sections, the inner pipes protrude from the outer pipes and are interconnected with using the appropriate connection, while the cavity in the junction of the upper and lower sections between the outer pipes and interconnected by a corresponding connection with the pipes of the upper and the lower sections are filled with thermal insulation and outside is covered by a shell covered by clamps, and on the outer pipes of each of the lower sections mounted fasteners for temporary fixation of ribs to support the insulating direction on the well walls during installation, characterized in that the joint pipes of the inner pipes between adjacent ends of the sections formed by compounds that ensure their self-centering and self-fixation of the position relative to each other, and the shell is drawn by clamps that extend beyond the diameter of the section, but not exceeding the gap between the section and the wall of the well, laid on the shell along the helix with the possibility of performing the functions of a centralizer of the connected sections when they are immersed in the well and directing the distribution of concrete when pouring it into the space between the outer wall of the section and the wall of the well.

Images