Method of isolating zone underground workings from groundwater and the method of installation of water intake equipment for technological well


E02D19/14 - by freezing the soil (in connection with sinking shafts E21D0001120000)

 

The invention relates to the field of underground construction, in particular for the construction and reconstruction of industrial wells in the area of sinking works. A method of isolating areas of work areas of underground production from groundwater in the area of technological wells, including the creation below Foundation level underground mine sealing ice jumpers and ledogorov fencing using the method of nitrogen freezing. The process of nitrogen freezing includes a step of gradually cooling to freeze the field of gaseous nitrogen and the subsequent stage of freezing with liquid nitrogen. Also, a method for implementation of works on installation and replacement of the equipment well protected posed above ice jumpers and ledogorov fence. The technical result of the invention is to provide a safe and economical method of isolating zone underground workings from groundwater in the area of technological wells, as well as the development of safe and cost-effective technology works on construction and reconstruction of production wells under the protection ledogorov peretse to the field of underground construction, in particular for the construction and reconstruction of industrial wells in the area of sinking works with the use of artificial freezing.

In the construction of various underground structures, such as underground or transport tunnels are widely used drilling technology well for various purposes (electricity, compressed air, concrete and so on).

During the drilling of production wells with surface casing (also referred to as casing strings) wells intersect the unstable water-saturated layers of soil (Quaternary deposits). In some cases, particularly when drilling artesian production wells used for groundwater exploration, opened Gdov horizon. An important feature of such wells is that the casing of wells not only pass through water-saturated soil layers, and are connected at the base with an unlimited array of pressure water Gdov aquifer. The pressure of the groundwater in the shallow underground workings is measured in tens of meters of the water column and within a casing of wells located in the immediate vicinity of said underground exp is arabolic or facilities set multimeter water column. The opening of Gdov aquifer can also occur during the drilling of other production wells, not originally designed for the extraction of groundwater.

Under these conditions, the attempted sinking works or opening of the casing bore for mounting the intake equipment without the use of special methods to ensure safety of doing such work, will inevitably lead to a breakthrough high-pressure groundwater in underground structures.

When constructing artesian production wells they set the cap, provided with equipment to remove water in the main water system (water facilities). During long-term operation of the casing and the intake equipment such wells are exposed to intense corrosion, resulting over time under the influence of current corrosion processes and high water pressure, a risk of violation of their integrity. If in the immediate vicinity of the artesian well is a zone of underground tunnels or underground structures (for example, main line tunnel or the lobby of the Metropolitan Museum of art), such leaks obsd who I am.

Therefore, to ensure protection of underground facilities from the ingress groundwater, as well as to allow the diversion of water directly in the area of the underground mine head, provided with equipment to remove water in the main water system, installed on the casing of technological wells in the area of underground workings, and not on the earth's surface (called surface). In this zone being constructed underground water intake chamber.

For the implementation of works on arrangement of underground water intake chamber and the installation of the tip, and to perform subsequent operations on their repair and reconstruction must work to lower the water level in the well or to cut off (isolate) coming on well under pressure from ground water area of sinking or repair work.

The most common methods used for such purposes, use a technique referred to as dewatering, including heavy pumping of groundwater through the well. Such technologies are described, in particular, Standards for design and production work on artificial lowering of the groundwater level in the od to the required level needed an extremely powerful and reliable pumps as well as electricity, ensuring their smooth operation, because any failure in the operation of the pump leads to an immediate rise in water level and inundation zone underground workings. Finally, this technology is not always acceptable for reasons of environmental safety.

As practice shows, in some cases, the most convenient to isolate the zone underground workings from groundwater are methods involving the use of freezing techniques aquifer (saturated) soils. However, widespread technology brine freezing of the soil was not sufficiently effective for pressure wells with high background temperatures and velocities of groundwater (www. georec. narod. EN/maq/1999n1/3.htm).

In the 70-ies of XX century was the technology of freezing of saturated soils using as refrigerant liquid and gaseous nitrogen (U.S. Pat. USA 3,943,722 [2] and 3,726,095 [3]).

Later freezing of Quaternary deposits (saturated soils) when carrying out the digging work was proposed method with the use of technology zonal nitrogen freezing of wells in which water-saturated soil in he Saint Petersburg Metro (Underground Railway) // Progress in Tunnelling After 2000. Vol. III, Patron Editore, Bologna 2001, p.p. 13-20 [4]).

To prevent flooding of underground facilities at the opening of artesian wells has been proposed a method including creating a sealing ice jumpers and ledogorov fence artesian wells using freezing with liquid nitrogen (Y. A. Filonov and other Zonal nitrogen freezing artesian wells - Underground space of peace, 5-6, 2000, S. 39-40, [5]).

In accordance with this known method below Foundation level of generation in the internal cavity of the casing between the area of operations (underground workings) and unlimited water array of Gdov aquifer create sealing ice jumper blocking the access of water to the area of newly constructed or existing underground workings through the internal cavity of the casing and into the annulus around the casing in the area of ice jumpers create logrotate the guard, preventing the ingress of water into the underground workings in the annular space. Thus between the production area and unlimited water array of Gdov aquifer is formed by sealing septum.

However, in accordance with nei cavity of the casing artesian wells, and in the peripheral wells drilled near frozen artesian well. In the first case, at the initial stage of freezing inside the casing is formed an ice dam, sealing the well, and the next step around casing is formed logrotate the fence. In the second case, on the contrary, first formed logrotate the fence, and then in the propagation of the freezing front from peripheral freezing device to freeze the well inside the casing is formed an ice dam.

The known method has a number of significant drawbacks that prevent its practical use. The most important of these disadvantages is the fact that freezing water and water-saturated soils with liquid nitrogen having a boiling point at atmospheric pressure of 196oWith, there is mushrooming of ice, the volume of which substantially exceeds the volume of water from which it is formed. This can lead to either rupture the casing due to a sharp increase in the pressure of the formed ice on the inside of the casing (when freezing device is located in its inner cavity), or to savlian lorazepama water-saturated soil (in the case when freezing devices are placed in the peripheral wells). Avalanche volumetric expansion of ice in a closed water-filled cavity under the top of the well can also lead to disruption of the tip of the well. In any of these cases, the result will be a breakthrough groundwater and flooding zone underground workings.

To enable safe conduct of works on repair and technological development wells under the protection of the ice partitions thickness of this partition must be large enough to ensure that she was able to keep the groundwater is under pressure, therefore the area of freezing should be of a sufficient height (up to several meters, depending on water pressure). In addition, it is necessary to provide conditions under which a sealing wall would isolate zone underground workings from groundwater in a period of time sufficient to carry out such work with a minimum expenditure of refrigerant.

Therefore, the present invention was the creation of a safe and economical method of isolating zone underground workings from groundwater in the area of technological wells, and RA the wells under the protection ledogorov partitions, created in this way.

The authors of the present invention, it was found that logrotate enclosure formed by the isolation zone underground mine in accordance with the known method [5] and designed to prevent the ingress of water into the underground workings in the annular space, when reaching a certain minimum volume capable of playing the role of insulating cryogenic battery to maintain a low temperature in the field of ice jumpers and prevent it defrost for a long period of time, sufficient to undertake the necessary work on the process well. However, achieving lenograstim fence required volume cannot be achieved with the implementation freezing in accordance with the known method in practice because of the above limitations of use of this method.

In addition, the authors present invention it was found that the introduction of nitrogen freezing stage cooling to freeze the area with gaseous nitrogen provides a gradual cooling of the frozen region and prevents the explosive spread of ice froh the th column. The authors also identified the optimal conditions for undertaking this process, allowing you to obtain the amount of frozen array (including ice jumper and logrotate the fence), sufficient for the safe conduct of work required, with a minimum flow rate of the refrigerant.

Therefore the task of the present invention is solved in that in the method of isolating zone underground workings from groundwater in the area of technological wells, including the installation of this zone zonal freezing device (zonal freezing devices) and create using the specified device (s) below Foundation level underground workings ice jumpers and ledogorov fence by nitrogen freezing, the process of nitrogen freezing includes at least two stages. The first of these stages (conventionally referred to within this application stage (a)) is filing with the freezing device evaporated nitrogen gas and thus the gradual cooling of the frozen area from ambient temperature to a temperature not lower than the temperature of boiling/condensation of nitrogen (specialist pornom pressure specified temperature is -196oC). Preferably the temperature to which it is cooled to freeze the area at this stage should be between the freezing temperature of water (0o(C) to boiling point/condensation of nitrogen. It is clear that in the area adjacent to the freezing device, the temperature of the frozen region is close to the temperature of the refrigerant supplied vaporized nitrogen gas), and as the distance from freezing this device, the temperature will rise.

At the next stage (stage (b)) is filing with the freezing device of liquid nitrogen, the displacement of him in freezing nitrogen gas, and is freezing with liquid nitrogen at a temperature not higher than the temperature of its boiling point. In the zone around that area of the freezing device, in which at this stage of the method is liquid nitrogen, water-saturated soil is frozen most intensively, and therefore in this zone are formed frozen ground (which is essentially part ledogorov fence) is significantly larger than around the site of the freezing device, where is getoperator ice jumpers and thereby prevents it from thawing during the time, sufficient to carry out the necessary works in the area of underground workings. The specified area is frozen, water-saturated soil in the framework of this application is called "cryogenic accumulator".

To create ice bridges and ledogorov fencing in accordance with the proposed method should be used at least one zonal freezing device, for example, such as described in the patent of the Russian Federation 2149240, [6], or the article Y. A. Filonov and other Way of zonal nitrogen freezing soils. Station, 1-2, S. 22, [7], or in [4].

In a preferred embodiment, the above stage (a), in which the cooling of the frozen region includes at least two stages. The first of these stages provide pre-cooling of the frozen region. In freezing device serves nitrogen gas, the temperature of which at the beginning of the cooling process should not be below -120oC. In the process of implementation of this step the temperature of the gaseous nitrogen is reduced to a value no lower than -180oWith, and its pressure freezing device increases from an initial pressure equal to atmospheric, the amount of not less than 1 hour At the next stage, further cooling of the frozen area by a further gradual lowering of the temperature of the injected gaseous nitrogen to the temperature of its boiling/condensation for at least 0.5 hour.

To create ice jumpers sufficient thickness, as well as to create volume ledogorov fence sufficient to prevent melting of this dam during the time necessary for carrying out of works on arrangement of the technological hole or reconstruction (replacement of worn water equipment), with a minimum consumption of liquid nitrogen, in a preferred embodiment of the proposed method stage (b) freezing with liquid nitrogen includes more than one stage. At the first stage of the discharge end of the supply pipe zonal freezing devices have a maximum depth, and freezing leads to the formation of the ice bridge and ledogorov fencing design capacity at lower design levels. Then the outlet end of the supply pipe zonal freezing device raise to a higher level and are freezing at this level until education ledogorov Ogre is necessary, the discharge end of the supply pipe raised above the next design level and repeat the process of freezing at this and subsequent levels to create the necessary volume of the frozen region. The person skilled in the art it is clear that the design depth, which is freezing, the total volume of the frozen region, and the thickness of the ice jumpers depend on a number of factors, including the temperature of the groundwater composition and saturation of soils, the depth of the aquifer, the water pressure in the borehole, the estimated duration of the work carried out under the protection of the created ice jumpers and ledogorov fence. When implementing a freeze on the second and higher design levels the flow of liquid nitrogen to levels below the appropriate project level, significantly restricted by the use of a labyrinth seal located at the discharge end of the supply pipe zonal freezing device below the outlet.

As was found by the authors of the present invention, the minimum time of freezing with liquid nitrogen at the stage (b) necessary to create a frozen array (i.e., ice jumpers and ledogorov fencing), about the PM

In the proposed method zonal freezing device may be placed either in the inner cavity of the casing freeze technological hole, either in the peripheral wells drilled near freeze well. However, depending on the task and technical capabilities can buritica one or more peripheral wells, preferably two or three wells. Peripheral wells may buritica both from the surface and from the zone of doing underground work (underground workings), in particular from the intake chamber. The distance from frozen technological hole to the peripheral wells may vary depending on the state of soil and groundwater temperature, the size of the diversion chamber (if drilling is carried out from the zone underground workings), the number of peripheral wells and other factors. In General, for economic reasons, it is advisable to position the peripheral wells at a distance of not more than 1.5 m from frozen technological hole.

When using two or more peripheral freezing device (i.e., freezing devices that are located in the peripheral the IU downhole liquid freezing device (ZHSU) (so that is, devices in which you are freezing with liquid nitrogen) is only one of the freezing devices, and other (other) works in the mode of gas downhole freezing unit (GSU) (i.e., devices in which you are freezing gaseous nitrogen). To implement this variant of the proposed method of freezing devices connected in such a way that one of the devices connected directly to the supply pipeline (i.e., the inlet of this device is connected to the supply pipe) and the other is connected in series so that the outlet of each freezing device through a pipeline connected to the inlet hole followed by a freezing device. When implementing the proposed method in accordance with this embodiment, after completion of the cooling phase freeze pane in freezing device is connected directly to the supply pipe (which can be called "first" freezing device) serving liquid nitrogen, while maintaining the feed rate and pressure, providing boiling of liquid nitrogen in the specified freezing device. Visby to provide liquid nitrogen freezing on the appropriate project level and prevent overflow of liquid nitrogen in the following freezing device. To ensure the specified height of the column of liquid nitrogen feed rate of liquid nitrogen and the pressure in the system to regulate the enrollment process on the basis of readings of temperature sensors located inside of the freezing device in the zone of freezing. Nitrogen, evaporating in the freezing device connected directly to the supply pipeline, expanding and is in a gaseous state flows through the pipeline in the following freezing device (which can be called "second"), providing the operation of the DSU, and then either sent to the system gazebos (if freezing system includes only two of the freezing device), or acts for the following freezing device (if the system is freezing includes more than two freezing devices). Thus the process of freezing with liquid nitrogen in freezing device connected directly to the supply pipe, is carried out simultaneously with the process of cooling gaseous nitrogen occurring in subsequent freezing devices. In this case, although the temperature of the gaseous nitrogen in each subsequent freezing device due to heat transfer increases by nescoe this mode of supply of liquid nitrogen in the field, located around the second and subsequent freezing devices operating in the gas mode, will be not only cooling, but also the freezing of water and water-saturated soil, although not as intense and not to such a low temperature as in the region adjacent to the first freezing device. In addition, it is known that even at the same temperature (at boiling point/condensation) freezing gaseous nitrogen by approximately 55% less effective than freezing with liquid nitrogen (see [7]). Therefore, it is also clear that the amount of frozen array formed around the second and subsequent freezing devices operating in the gas mode, will be significantly less than the volume of frozen array formed around the "first" freezing devices operating in liquid mode.

Therefore, to create a frozen array of the required amount in the region of each freezing device may be required to provide each of the freezing device in liquid mode. To do this, after the formation of ice bridges and ledogorov fencing project form in the field "first" freezing device (i.e., freezers and refrigerators with the specified freezing device to another ("second") freezing the device. Then carry out the supply of liquid nitrogen in the second freezing device in the mode described above for freezing device connected directly to the supply pipeline. Thus again provide one of the freezing device (in this case "second") mode ZHSU, and the other in the mode of the DSU.

Such switching of a feed line and connecting pipelines can be performed several times, in order alternately to provide each of the freezing device as freezing device connected directly to the pipeline, in this case, in the mode of ZHSU.

As mentioned above, the isolation zone underground workings from groundwater is to provide the installation and reconstruction of water intake equipment in the specified zone. Therefore, in another aspect, the present invention provides a method of installation of water intake equipment for technological well in the area of underground workings, including the step of isolating the zone underground workings from groundwater and installation stage intake equipment. This izolirovannye the method of installation of water intake equipment includes two main embodiment. One of these examples of implementation of this method provides for the arrangement of the tip of technological wells (i.e. the installation of water-supply equipment) in the area of conducting an underground tunnel works in the case when the barrel (casing) technological wells initially passes from the surface to the arch of Gdov aquifer. In this case, for installation on technological borehole in the zone underground mine water intake equipment is necessary in this area in the so-called intake chamber to open the casing dividing it into two parts. On the bottom of these parts, going from the base generation (intake chamber) to a level below the groundwater level, establish water intake equipment, which usually includes a cap having a valve, a pipe for draining water in the main water system, and control instruments for measuring water pressure. The upper part of the split casing extending from the surface to the top of the arch of the diversion camera, can be used, in particular, for ventilation or supply of electricity in the intake chamber.

In accordance with this example, the first paragraph is under the protection of the thus created ice jumpers and ledogorov fence exercise opening of the casing in the area of underground workings above the level of Foundation excavations, then on the lower part of the opened casing install the necessary water intake equipment.

From an economic point of view in most cases the preferred option of isolating the production zone, in accordance with which the freezing device is injected into the internal cavity of the casing technological hole.

Another example of the method of installation of the water intake equipment refers to the reconstruction of the technological hole when the tip in the water the camera is already equipped, and trunk technological wells (i.e., its casing) already described above is divided into upper and lower parts. In this case, most often you need to replace the existing worn-out water equipment and therefore the installation phase of the intake equipment in this embodiment of the proposed method is preceded by an additional step dismantling of worn-out equipment.

This example implementation of the proposed method, in turn, also includes several options.

One of these options apply to the case when the replacement needs only the tip of the well, thus requiring replacement of the head of the well, the Los Angeles water access. In accordance with this embodiment of the invention the upper part of the casing connected to the specified lower part of the casing, provided with an opening valve, by means of a connecting insert installed within the intake chamber, thus restoring the trunk of technological wells up to the surface. The restoration of the wellbore is carried out at closed valve. In this way the resulting restored trunk technological hole open valve blocking the access of water, resulting in the trunk of a set of so-called piezometric water level (pressure level, installed in the borehole). Then in the inner cavity of the casing restored trunk mount freezing device and carry out the isolation zone underground workings from groundwater in accordance with the above-described respective variant of the method of isolation (installation freezing device into the internal cavity of the casing). After completion of the process of nitrogen freezing and ice jumpers and ledogorov fencing design capacity under the protection of the formed Germany is following what is set on the lower part of the casing a new water intake equipment.

One of the special cases described above variant of the proposed method can be used when reconstruction requires not only equipment tip well, but casing. In this case, the method should include the number of additional stages associated with the reconstruction of the casing. So, after the restoration of the barrel technological hole and setting it piezometric water level in the inner cavity restored trunk mount a new pipe casing (referred to as "repair"), which is usually made of corrosion-resistant material (e.g. stainless steel). Then inside the set (mounted) freezing the device. After plugging (usually by cementing) the annular space between the worn pipe bottom of the casing and the new pipe casing. Then perform the isolation zone underground workings from groundwater, as described in the previous paragraph. In this embodiment of the proposed method together with the dismantling of the casing and worn-out water intake equipment, under the protection formed by freezing of the ice bridge, new lower part of the casing are mounted a new water intake equipment.

Another variant implementation of the proposed method can be used in the case when the valve on the bottom of the casing may not be opened, or when the lower end of the casing is mounted so that installation connecting the insertion and recovery of the wellbore to the surface without prior disassembly of the tip is impossible. In accordance with this embodiment of the method in the first stage of the work near the trunk of technological wells are drilled peripheral wells. Peripheral wells may buritica as from the zone underground mine (from the intake chamber, and the surface, depending on the technical possibilities. After peripheral wells are drilled, they are mounted freezing device and carry out the isolation zone underground workings from groundwater in accordance with the above-described respective variant of the method of isolation (option, which includes the drilling of peripheral wells). After completion of the process of nitrogen freezing and education sealing ice jumpers and ledogorov fencing design capacity under their protection with the lower part of the e equipment. After unfreezing (melting) ice jumpers hole can be operated in normal mode.

This variant of the proposed method can be used if necessary reconstruction of the casing. When this freezing should be carried out at a depth sufficient to repair casing required length could be installed above formed by the freezing of the ice bridge. In this case, the installation phase of the intake equipment includes the installation of a new (repair) pipe casing and plugging the annulus between the bottom of the deteriorated pipe casing and the new pipe casing, and equipment installation tip repaired thus casing.

However, in practice not always have the technical ability of the peripheral drilling wells to a depth sufficient to install and repair pipe casing in such a way. This is because, while repairing the casing it is necessary that the bottom edge of the repair pipe casing was located at a sufficiently great depth (usually no less than Hume) relative uravneniem freezing using peripheral freezing devices similar to the one described above, but includes a number of additional stages associated with the reconstruction of the casing. In accordance with this option after surgery dismantling of worn-out water intake equipment in the area of underground workings (intake chamber) connect the upper part of the casing with the lower part of the casing by installing the connecting insert, thus restoring the trunk technological hole. Then after thaw (thaw) ice bridge, under the protection of which was carried out the dismantling and restoration of the barrel, restored trunk is set piezometric water level. After establishing the level specified in the internal cavity restored trunk mount new (repair) pipe casing. Inside the new pipe casing set freezing device. After plugging annulus between the worn pipe bottom of the casing and the new pipe casing, and then perform the isolation zone underground workings from groundwater in accordance with the appropriate version of the method of isolation described above (the variant with the location of the freezing ustroennogo array (ice jumpers and ledogorov fencing) disassemble the connecting box and carry out the opening of the new pipe casing above the Foundation level of output. To facilitate subsequent installation of equipment autopsy should be carried out so that the bottom of the new pipe casing were above the specified level. Then set on the lower part of the repaired casing new head comprising a latch, and a new water intake equipment. After unfreezing the ice jumpers freezing device can be removed from the well, and the well can be operated in normal mode.

When performing dismantling and installation of equipment, under the protection of the ice jumpers, you must remove the water from the cavity of the casing above the bridge. Removal of water from this area could theoretically be performed after the process of freezing as by pumping, or by displacing the compressed gas. However, as we know, during freezing of water volume of ice substantially exceeds the volume of water from which it is formed. Therefore, when the freezing of water in a limited volume inside the cavity of the casing between the top hole and formed ice bridge experience significant stress, which can lead to the destruction of the casing before the implementation process of nitrogen freezing to lower the water level in the well casing string, on which work is being carried out by feeding into the internal cavity of the specified casing compressed gas. When the water level in the casing is reduced to a level corresponding to the top design level of the formed ice jumpers. In practice, it is advisable to maintain the water level in the well is slightly above the top design level of the ice bridge, so that the possible error of pressure measurement is not influenced in a negative way on the thickness of the formed ice jumpers. As the compressed gas may be air or nitrogen gas.

The above methods are most appropriate to carry out the work on the artesian technological wells, originally designed for the extraction of groundwater, however, can be used to carry out the work on technological wells for other purposes, while drilling which opened the horizon of groundwater.

In Fig.1 shows a diagram of the construction of the freezing equipment in the isolation zone underground mine with the peripheral drilling wells in accordance with Example 1, and the form of frozen array formed after freezing on the bottom design level.

Example 1.

In Fig. 3 shows a scheme of reconstruction of the casing technological wells and construction of the freezing device located in a restored trunk technological wells in accordance with Example 2.

In Fig. 4 shows a diagram of freezing using a freezing device located in a restored trunk technological hole, and the shape of the formed frozen array in accordance with Example 2.

On these figures the soil indicated a cross-hatch pattern with dots, water - horizontal strokes, ice - triangles, frozen, water saturated soil triangles on the background of the sloping hatch.

Example 1 Reconstruction of technological equipment of the well using the method of isolating the production zone. it includes drilling the peripheral wells Of the internal cavity of the intake chamber 1 at a distance of 1 m from the bottom 2A of the casing barrel technological hole 2, requiring replacement of water intake equipment and the repair of casing, drilling two working peripheral wells 3 and 4 (see Fig.1). In this example, cryogenic vessels (tanks) 5 containing liquid nitrogen, placed on the surface (Dosta (supply pipe) and pipe 7 for removal of the spent nitrogen (piping system gazebos) mounted in the cavity of the upper part 2B of the casing and fixed on the surface above the mouth of technological wells. In the peripheral wells 3 and 4 are mounted downhole freezing device 3A and 4A, respectively, with the discharge end of the supply pipe of each freezing device on the bottom design level of freezing. In this example, using freezing device, the discharge end of the supply pipe which is provided with a labyrinth seal, substantially limiting the flow of liquid nitrogen to levels below the specified compaction, such as the device described in [4]. The supply pipe 6 is connected with a cryogenic tank 5 and freezing device 3A flexible hoses 6A and 6b, respectively. Freezing device 3A and 4A are connected with a flexible hose 6b. Freezing device 4A is connected with the pipe 7 system gazebos through conduit 7a.

After installation and verification system freeze leak into the internal cavity of the casing (in the area between the bottom walls of the casing 2A and the tip 8) serves compressed air, lowering the water level in the well (water surface) to the top design level of the formed ice jumpers UPV (see Fig. 2). Expert it is clear that the control urbalacone design pressure of water at a specified level (OLA1).

After lowering the water levels begin to flow into the system freezing gaseous nitrogen having a temperature of not lower than -120oWith gradually increasing pressure in the system to 0.18 MPa while lowering the temperature of the nitrogen to a value no lower than -180oC. the gaseous nitrogen in this mode is carried out for 2 h, then for 0.5 h gradually lower the temperature of the nitrogen to -196oC.

Then start the supply of liquid nitrogen temperature of -196oWith freezing device 3A, ensuring its operation downhole liquid freezing device (ZHSU). Feed rate adjust during the freezing process, based on the readings of temperature sensors located inside of the freezing device, thus to ensure that the design height of the column of liquid nitrogen in the case of the freezing device and boiling nitrogen in freezing device 3A. Nitrogen, wikipedi in freezing device 3A, flexible metal hose 6b is supplied in a gaseous state in a freezing device 4A, ensuring freezing device 4A in the mode of the DSU, and then through the hose 7a enters the pipeline 42 h to education at the lower level of freezing ice jumpers 9a and ledogorov fence 9b, includes the area of cryogenic battery 9V.

After this time the supply of liquid nitrogen to stop and raise the discharge end of the supply pipe freezing device 3A on the next (second) design level, then repeat the process described in the previous paragraph.

After freezing with liquid nitrogen on the second project level, the supply of liquid nitrogen again stop and perform switching of the flexible conduit 6b with the supply pipe freezing device 3A on the supply pipe freezing device 4A, the switching flexible metal hoses 7a with the exhaust pipe freezing device 4A to discharge pipe freezing device 3A, and switching one end of the flexible conduit 6b with the exhaust pipe freezing device 3A on the supply pipe freezing device 3A, and the other end of the flexible metal hoses with 6V supply pipe freezing device 4A to discharge pipe freezing device 4A.

Then the process described in the three previous paragraphs, I repeat, enabling a freezing device 4A in the mode of ZHSU, and freezing devices 3A - mode is uncove fence 9b, including the area of cryogenic battery 9V), having the form shown in Fig.2. The total volume of the frozen area, including ice jumper and logrotate fence, about 25 m3. The consumption of liquid nitrogen to freeze - 20 t, time of thawing ice jumpers - not less than 96 hours

When reconstruction needs only equipment tip well, all the necessary dismantling and installation of equipment can be carried out after the formation of the sealing frozen array 9 under his protection, and after unfreezing jumpers well may be put into operation.

If necessary reconstruction not only end well, but the casing transactions described below in Example 2.

Example 2 1. Reconstruction of the casing After the formation of the sealing frozen array 9 formed as described in Example 1, the supply pipe 6 and the pipe system gazebos 7 will be dismantled and removed from the upper part 2B of the casing. At the same time under the protection of the sealing frozen array 9 with the lower part 2A of the casing technological hole disassemble worn-out water Obrador hermetically connected to the bottom part 2A by means of the coupling insert 2B, restoring the barrel 2 technological hole to the surface of PD (Fig.3). The connection is carried out by welding.

After the melting of the ice jumpers 9a restored in the barrel 2 is set piezometric water level OLA2.

Then restored inside of the barrel with the surface of DP for each section mount and put a new (repair) the pipe 10 of the casing of stainless steel. After its installation into the internal cavity of the new pipe 10 of the casing with the surface mounted downhole freezing device 11, with the discharge end of the supply pipe freezing device 11 on the bottom design level of freezing. As in Example 1, in this case, the use of zonal freezing device, the discharge end of the supply pipe which is provided with a labyrinth seal, substantially limiting the flow of liquid nitrogen to levels below the specified compaction. Cryogenic tank 5 is connected to the supply pipe freezing device 11, by connecting the specified container with the inlet pipe freezing device 11 through a flexible conduit 12 and the outlet pipe freezing Ostroumova space between the bottom of the casing 2A and the lower part 10A of the new pipe casing. For plugging the annulus using a special waterproof cement, which is served by pipes (not shown) located in the cavity between the wellbore 2 and the new pipe 10 of the casing. Cementing is carried out in the area between the wall of the old, worn-out pipe casing and the wall of the bottom part 10A of the new pipe from the bottom of the new pipe to the level of the upper edge of the lower portion 2A of the casing. The area of the casing 14 shown in Fig.3 and 4. Hit cement in the region of the well below the bottom of the new pipe casing is substantially restricted by the use of o-ring seals 10B mounted on the lower edge of the new pipe 10 of the casing, prior to installation of this new pipe.

As a result, after the reconstruction of the renovated lower part of the casing includes two tubes: the lower part of the old (worn out) pipe casing 2A and the lower part 10A of the new pipes made of corrosion-resistant material, between which is a layer of waterproof cement 14.

2. The isolation zone underground mine using a freezing device located in the trunk of technological wells is, the area between the walls of the new pipe 10 of the casing and the housing of the freezing device 11, by means of the compressor 15 serves compressed air, lowering the water level in the well to the top design level of the formed ice jumpers Opus (Fig.4). The water level in the well is controlled by the magnitude of the pressure of the compressed gas in the cavity of the casing, as described in Example 1.

After lowering the water levels begin to flow into the system freezing gaseous nitrogen having a temperature of not lower than -120oWith gradually increasing pressure in the system to 0.15 MPa while lowering the temperature to a value no lower than -180oC. the gaseous nitrogen in this mode is carried out for at least 1 h, and then for 0.5 h gradually lower the temperature of the nitrogen to -196oC.

Then start the supply of liquid nitrogen temperature of -196oWith freezing device 11, ensuring its operation downhole liquid freezing device (ZHSU). Feed rate adjust during the freezing process, based on the readings of temperature sensors located inside of the freezing device, thus to ensure that the design height of stavast enters the pipe gazebos 13 in the gaseous state. The supply of liquid nitrogen in freezing device 11 is carried out for 20 h before the formation of the lower level of freezing ice jumpers 16A and ledogorov fence 16B.

After this time the supply of liquid nitrogen to stop and raise the discharge end of the supply pipe freezing device 11 to the next design level, then repeat the process described in the previous paragraph.

Upon completion of the above process receive sealing frozen array 16 (ice jumper 16A and logrotate fence 16B, which includes the area of cryogenic battery 16B) design volume having the shape shown in Fig.4.

The total volume of frozen array, including ice jumper and logrotate the fence, about 10 m3. The consumption of liquid nitrogen to freeze - 10 t, time of thawing ice jumpers - not less than 48 hours

3. Installation of a new water intake equipment Under the protection of the formed sealing frozen array 16 disassemble the connecting box 2B and cut out a section of new pipe casing, and a section of the hull of the freezing device 11 above the upper edge of the lower part 2A of the old pipe casing kaloleni set flange 17 and install the new tip 18 of stainless steel. Then mount the outlet pipe connecting the well to the main water supply system, and the measuring instrument (pressure gauge) (not shown).

To enable extraction of the freezing device from the well, after mounting the head once again restore the body freezing device 11 and the new pipe casing to the surface, and then after thawing ice jumpers 16A and the establishment of the new pipe casing 10 piezometric level UPV of wells on the surface extract freezing device 11. Using compressed air to lower the water level in the well to a level below the new cap 18, close the valve on the cap 18 and dismantle part of the new tubes 10 of the casing above the well head 18. After this process, the well can be put into operation.

All works on installation of equipment, as well as the process of nitrogen freezing is accompanied by control and test for leaks.

The present invention is not limited to the above examples only to illustrate specific variants of its implementation. It is assumed that the invention includes is included within the scope of the following formula, reflecting the essence of the present invention.

Claims

1. Method of isolating zone underground workings from groundwater in the area of technological wells, including installation in a specified area of at least one zone of freezing devices and creation below Foundation level underground workings ice jumpers and ledogorov fence by nitrogen freezing, characterized in that the process of nitrogen freezing process involves the following stages: (a) filing with the freezing device evaporated gaseous nitrogen and gradual cooling to freeze the area from ambient temperature to a temperature not lower than the boiling point of nitrogen; (b) filing with the freezing device of liquid nitrogen, preemption in the field of the freezing gaseous nitrogen and implementation freezing with liquid nitrogen at a temperature not higher than the temperature of its boiling point, and stage (a) includes the following stages: pre-cooling of the frozen area by feeding in a freezing device of nitrogen gas while gradually lowering the temperature of the injected gaseous nitrogen from a value no lower than -12 is that from atmospheric up to at least 0.15 MPa for at least 1 h, and further cooling of the frozen area by gradually lowering the temperature of the injected gaseous nitrogen to the temperature of its boiling/condensation for at least 0.5 hours

2. The method according to p. 1, wherein stage (b) freezing with liquid nitrogen includes more than one stage, and at the first stage, the discharge end of the supply pipe zonal freezing devices have a maximum depth, and freezing leads to the formation of the ice bridge and ledogorov fencing design capacity at lower design levels; at each subsequent stage of the discharge end of the supply pipe zonal freezing devices have consistently higher design levels of freezing, and freezing leads to the formation of ledogorov fencing design capacity at the appropriate project level, and the flow of liquid nitrogen to the levels below the appropriate project level, significantly limit using a labyrinth seal located at the discharge end of the supply pipe freezing device below the outlet.

3. The method according to any of paragraphs. 1 and 2, characterized in that samoregulyatsiya fact, that freezing device is injected into the internal cavity of the casing technological hole.

5. The method according to any of paragraphs. 1-3, characterized in that one or more of freezing devices have respectively one or more peripheral(peripheral) well(wells) drilled near the technological hole.

6. The method according to any of paragraphs. 1-3 or 5, characterized in that use two or more freezing device connected in series so that one of these freezing devices are connected directly to the supply pipe, and a supply of liquid nitrogen in freezing device is connected directly to the supply pipeline, implementing, maintaining the feed rate and pressure, providing boiling of liquid nitrogen in the specified freezing device and the flow of nitrogen in the following freezing device in a gaseous state.

7. The method according to p. 6, characterized in that after the formation of ice bridges and ledogorov fence design forms in the field of the freezing device connected directly to the supply pipe, switch the supply pipe with the specified samarajiva another freezing device, maintaining the feed rate and pressure, providing boiling of liquid nitrogen in the specified another freezing device and the flow of nitrogen in the following freezing device in a gaseous state.

8. The method according to p. 7, characterized in that the supply pipe is connected alternately to each freezing device, ensuring that each freezing device as freezing device connected directly to the supply pipe.

9. The method according to any of paragraphs. 1-8, characterized in that the technology well is an artesian well.

10. The method of installation of water intake equipment for technological well in the area of underground workings, including the step of isolating the zone underground workings from groundwater and installation stage intake equipment, characterized in that the isolation zone underground workings from groundwater is carried out in accordance with the method according to any of paragraphs. 1-9.

11. The method according to p. 10, characterized in that the casing technological hole extends from the surface to a level below the groundwater level.

12. The method according to p. 11, characterized in that after the th generation above the level of Foundation excavations, then on the lower part of the opened casing install the intake equipment.

13. The method according to any of paragraphs. 10-12, characterized in that the isolation zone underground workings from groundwater is carried out in accordance with the method according to p. 4.

14. The method according to p. 10, characterized in that the casing technological hole is from the top, passing from the surface to the top of the arch underground workings, and the lower part that are continuous from the Foundation of the specified underground production to a level below the groundwater level.

15. The method according to p. 14, characterized in that it further includes the step dismantling of worn-out water equipment prior to the installation phase of a new water intake equipment.

16. The method according to p. 15, characterized in that the upper part of the casing connected to the lower part of the casing, provided with an opening valve blocking the access of water, connecting the insert to be installed in the area of underground workings; in this way the resulting restored trunk technological hole open valve blocking the access of water, resulting in the trunk is set piezometric URS underground production from groundwater in accordance with the method according to p. 4; under the protection of the formed ice jumpers disassemble the connecting box and worn-out water intake equipment, set on the lower part of the casing a new water intake equipment.

17. The method according to p. 16, characterized in that after the establishment in a restored trunk technological hole piezometric water level in the inner cavity restored trunk mount a new pipe casing, and a freezing device mounted inside a casing, mounting it in the inner cavity of the new pipe casing; after installation of the freezing device plugging annular space between the lower part of the casing and the new pipe casing; at the stage of dismantling the casing and worn-out water equipment additionally carry out the opening of the new pipe casing above the Foundation level of output.

18. The method according to p. 15, characterized in that near the trunk of the technological hole from the zone underground workings or with the surface of the Buryat peripheral wells; in the peripheral wells set freezing device and carry out the isolation zone underground workings from pony of the casing remove the worn-out water equipment; mounted on the lower part of the casing a new water intake equipment.

19. The method according to p. 18, characterized in that between the operation and dismantling of worn-out water intake equipment and the installation of a new water intake equipment perform the following additional operations: the upper part of the casing connected to the lower part of the casing connecting the insert to be installed in the zone underground workings, thus restoring the trunk technological hole; after thawing ice jumpers and establishment in a restored trunk technological hole piezometric water level in the inner cavity restored trunk mount a new pipe casing; inside the new pipe casing set freezing device and plugging the annular space between the bottom of the casing and the new pipe casing; carry out the isolation zone underground workings from groundwater in accordance with the method according to p. 4; under the protection of the formed ice jumpers disassemble the connecting box and carry out the opening of the new pipe casing in the area of underground workings above tochnogo freezing the water level in the well casing string is reduced to the level corresponding to the top design level of the ice bridge, by filing in the internal cavity of the casing compressed gas.

21. The method according to any of paragraphs. 10-20, characterized in that the technology well is an artesian well.

 

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Heated pile // 2250302

FIELD: heat engineering constructions.

SUBSTANCE: invention can be used as supports of different construction on permafrost. Proposed heated pile has reinforced concrete or metal shaft with inner or outer heated pipe in form of ribbed evaporator and condensers provided with metal strip ribbing arranged over ground surface with inclination to vertical part of shaft. Novelty is that heated pile is made T-shaped, and heated pipe in form of ribbed evaporator is made symmetrically double relative to axis of shaft with connection of some ends or its evaporators, other ends being connected with condensers. Evaporator ribbing is made in form of upward convex ring surfaces with central passes secured on inner surfaces of walls of heated pipe evaporators and uniformly distributed in height, and metal strip ribbing of condensers is element of horizontal part of T-shaped heated pile.

EFFECT: improved efficiency of heated pile, facilitated replacement of pile in case of failure.

2 cl, 4 dwg

FIELD: building heat-engineering structures, particularly for forming supports of different structures in permafrost areas.

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EFFECT: increased efficiency of ground cooling around the pile.

4 cl, 1 dwg

FIELD: hydraulic building, particularly to create water-tight frozen shields having height up to 100 m or more.

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EFFECT: increased operational efficiency due to increased capacity of liquid coolant unit to carry away heat from ground related to tall freezing column as a whole and to separate parts thereof along with uniform distribution of heat removed from freezing column parts.

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1 dwg

FIELD: improving or preserving soil or rock by thermal, electrical or electro-chemical means, particularly by freezing.

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EFFECT: improved economical efficiency and performance, increased manufacturability and extended functional capabilities.

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