RU2645539C1 - Device for sampling water from subglacial water bodies - Google Patents

Abstract

FIELD: ecology.

SUBSTANCE: invention relates to devices for sampling water from subglacial water bodies to study the microbiological and geochemical composition of water. Device comprises an outer casing, located with a gap inside it, internal vessel for sampling a sample of the water being examined, a piston with electromagnet is installed inside the vessel for sampling a water sample. On the lateral surface in the upper part of the inner vessel opening is made for the entry of the analyzed sample of water into the vessel, another hole is made in the bottom of the inner vessel for draining water into the outer shell. Inner vessel is provided with a lid with a shoulder sealingly surrounding outer part of inner vessel, the lid with a collar is mounted on the inner vessel with a gap formed at the top. In the gap between the outer body and the inner vessel is a tube that is sampling, one end of which is withdrawn to the outside through a hole in the bottom of the outer casing. Upper part of lid of inner vessel has two through holes with plugs, through the entire length of the lid of the lid, a through vertical opening is made, into which the second end of the sampling tube seals. Sideways from this opening in the collar towards the inner vessel are made two holes, the first of which is aligned with the opening on the wall in the upper part of the inner vessel for receiving the analyzed water sample, and the second hole in the collar is aligned with the upper gap between the lid and the edge of the inner vessel to provide communication with the gap between the inner vessel and the outer casing. Heating elements are installed on the outer part of the sampling tube and in the gap between the outer body and the inner vessel, the electromagnet of the piston has a cable that is projected onto the ice surface of the reservoir.

EFFECT: improving the quality of the sampled sample.

3 cl, 3 dwg

Description

The invention relates to a device for sampling from subglacial reservoirs to study the microbiological and geochemical composition of water.

Devices of this purpose work in special conditions, especially with regard to the work carried out in Antarctica when taking samples from lakes covered with ice:

- the well has a small diameter (<150 mm) and a depth of several kilometers;

- the well is filled with drilling fluid with a temperature several tens of degrees below the freezing temperature of water;

- the pressure in the lake reaches several hundred atmospheres;

- lowering the device into the well is carried out using a load-bearing electric cable.

The design requirements are as follows:

- the process of water withdrawal must be sterile;

- ingress of drilling fluid into the lake and into the water sample should be excluded;

- when raising a water sample, it should not turn into ice;

- the volume of the water sample should be more than 1 liter.

A device is known according to copyright certificate No. 1488717 "Device for sampling liquid samples from ice massifs". The device is designed to obtain samples from ice for subsequent microbiological analysis and other types of studies that require sterility of the sampling process. The device consists of nodes: sampling, erosion, heaters, sealing, control unit.

The disadvantage of this device is the design complexity and the likelihood of contamination of the under-ice reservoirs by extraneous microflora, as well as the fact that the water for analysis is obtained in the form of samples from ice.

A device is known according to the patent of the Russian Federation No. 2182225 "Thermoborer sampler" for sampling ice and water when drilling wells in ice sheets, as well as aseptically opening glacial reservoirs with subsequent reliable isolation from an upstream wellbore filled with drilling fluid. [2]

The body of the sampler is a thick-walled pipe and is connected to the ground control panel of the load-carrying cable. The working and control cores of the load-carrying cable are connected to the electronic control unit. The sensor system and the electronic unit provide the necessary mode and technology for sampling, constant monitoring of the progress of the sampling process in the well, and the possibility of prompt intervention by the operator from the ground console in the sampling process. After a well is drilled in the ice, to drill the remaining part until it contacts the surface of a subglacial lake, a thermal drill sampler on a load-carrying cable is lowered to the bottom of the well. During drilling, the lower surface of the thermal needle and the conical surface of the heat core are in constant contact with the ice face. When the thermal needle reaches the surface of the lake, the contact sensor will react. Then the signal goes to the control panel and from there a command is given to turn off the power of the crown and stop the drilling process. At the same time, using the readings of special sensors, the pressure difference between the column of drilling fluid in the well and the water in the lake is estimated. If the pressure of the filling fluid is less than or equal to the pressure of the water in the lake, the rise of water into the wellbore to a predetermined height occurs when the sampler is raised. If the pressure of the liquid in the well is higher than the pressure in the lake, a series of measures are taken to bring the existing conditions to the required ones, while the adjustment process is controlled by the operator using the sensors provided for this. After creating conditions for the excess of pressure in the lake over the pressure in the well, the sampler is raised to a certain height, and at the same time, lake water rises into the well. After that, work in the well is stopped for the period of freezing of lake water rising into the well. Then, a sample of ice formed from lake water is taken with an electromechanical drill. The remaining ice is not drilled, which ensures complete isolation of the wellbore from the surface of the lake and thereby eliminates the risk of contamination.

The disadvantages of the device are as follows:

1) the complexity of the design of the sampler, insufficiently developed sampling technology, which subsequently requires the use of a drill to extract frozen water as a sample, which pollutes the sample;

2) the impossibility of taking a liquid water sample, while for microbiological studies, water samples that have not been frozen are of particular interest.

As a prototype, the device according to the patent of the Russian Federation No. 2244913 "Device for sampling from under-ice reservoirs" [3] is considered.

The device comprises: a cylindrical housing in which the lower and upper heaters are mounted, a load-carrying cable for carrying out tripping operations, a cable lock for mounting the device on a load-carrying cable, an electrical connector block, a unit containing a set of parallel-connected cassettes, each of which has a microbiological filter (for example: a 0.23 micron polycarbonate filter), two solenoid valves for isolating the test sample from the environment and a pump for pumping the test water through the unit, the pipe Bani filtered water into the lake.

The device operates as follows. After a well has been drilled through the ice stratum and a borehole has opened a sub-ice reservoir, a drill is removed from the well. At the same time, a certain part of the water rises into the well until the pressure in the reservoir is equal to the column of liquid being poured into the well. Then, a sampling device with a pre-sterilized filter block to a predetermined depth is lowered through a well into the reservoir under investigation by means of a load-carrying cable. Since during the round-trip operations, the water that has risen into the well may freeze on the walls of the well, the device is lowered with the bottom heater turned on. At a given depth, the electromagnetic valves open, turn on the pump, which provides subglacial water to the inner vessel, which pumps the test water through a block containing a set of parallel-connected cassettes with microbiological filters - (unit for receiving a sample of the studied water). At the same time, water is pumped through all the cassettes of this filter unit in parallel, due to which the total area of the filters with a relatively small diameter of the sampler can significantly increase the volume of the test sample. Filtered water through a pipe flows back into the lake. At the end of the sampling process, both electromagnetic valves close, turn off the pump, and the device is removed from the well. When lifting the device include an upper heater, which calibrates the well in case of freezing of the water that has risen from the subglacial reservoir to the lower part of the well. After removing the device from the well, a block with cassettes is removed from it together with electromagnetic valves in the closed position and transferred to specialists for examination.

The disadvantages of the device.

1) The device does not provide high-quality sampling. This is due to the presence of an open cavity in front of the inlet valve, which, when lowering the device through the well, will be filled with the drilling fluid contained in the well. When the valve is opened and the pump is turned on, a portion of the drilling fluid from the cavity will enter sterile filters and contaminate them.

2) A portion of the drilling fluid contained in the cavity in front of the inlet valve passes through the device and enters the lake through the pump and the outlet valve, which will lead to pollution of the under-ice reservoir.

3) It is not intended to clean the outer casing of the device from traces of drilling fluid after the device has passed a well filled with drilling fluid. Drilling fluid from the outer walls of the body will enter the lake, which will lead to pollution of the ice reservoir.

4) The presence of active mechanical devices: a pump and valves, reduces the reliability of the device under high pressure in subglacial water bodies.

The technical effect of the claimed invention is to provide better and environmentally friendly sampling of water from an ice body of water and to deliver a sample to the surface in a liquid state in the absence of electromechanical devices and pressure drops on the walls of the device.

The technical effect is achieved due to the fact that in the device for sampling water from under-ice reservoirs, including an outer casing, an inner vessel for sampling the test water located inside it, heaters, holes in the outer casing and the inner vessel, the top of the outer casing having means for fixing the lifting mechanism, and the hole in the bottom of the outer casing is designed to take the analyzed water, the new is that the outer casing and the inner vessel are installed with some clearance, and inside a piston with an electromagnet is installed for sampling water, and a hole is made on the side surface in the upper part of the inner vessel for the analyzed water to enter the vessel; another hole is made in the bottom of the inner vessel for draining water into the outer case, the inner vessel having a lid with a collar hermetically covering the outer part of the inner vessel, and a lid with the collar mounted on the inner vessel with the formation of a gap at the top, and in the gap between the outer case and the inside the tube contains a sampling tube, one end of which is brought out to ensure tightness through the hole in the bottom of the outer case, the upper part of the lid of the inner vessel has two through holes with plugs, and a through vertical hole is made inside the flange of the cover along its entire height, into which the second end of the sampling tube is sealed, and two holes are made laterally from this hole in the collar towards the inner vessel, the first of which is aligned with the hole a wall on the wall in the upper part of the inner vessel for the arrival of the analyzed water sample, and the second hole in the shoulder is aligned with the upper gap between the lid and the edge of the inner vessel to ensure communication with the gap between the inner vessel and the outer case, and heating elements are installed on the outer part of the sampling tube and in the gap between the outer casing and the inner vessel, the piston electromagnet has a cable brought to the ice surface of the reservoir.

Thermal insulation is provided in the device for sampling water from under-ice reservoirs between the outer casing and the inner vessel.

In the device for sampling water from under-ice reservoirs, one of the openings in the upper part of the lid of the inner vessel provides ultra-pure gas, for example, argon, to the inside of the vessel, and the other hole in the upper part of the lid of the internal vessel provides sterile removal of the selected test water sample from the internal vessel to the outside.

In FIG. 1 is a view of the device before sampling water from a lake (piston at the top).

In FIG. 2 is a view of the device after taking a water sample from the lake (piston below).

In FIG. 3 is a view of the device at the time of removal of the sampled sample from the inner vessel (piston below).

The device contains: 1 - an internal vessel for sampling water; 2 - the lid on the inner vessel, 2-a - the flange on the lid (the lid with the shoulder tightly covers the outer part of the inner vessel and is installed on the inner vessel with a clearance above); 3 - a hole with a cap on the lid to remove samples of the investigated water from the inner vessel (1); 4 - a hole with a plug on the lid (2) for supplying gas to the inner vessel; 5 - a magnet in the inner vessel; 6 - a piston mounted inside the inner vessel; 7 - hole in the bottom of the inner vessel; 8 - hole in the upper lateral part of the inner vessel; 9 - the outer casing, the outer casing and the inner vessel are installed with some clearance; 10 - hole in the bottom of the outer casing; 11 - a sampling tube located in the gap between the outer casing (9) and the inner vessel (1); 12 - the second side hole in the flange between the lid (2) and the edge of the inner vessel (1) to provide communication with the gap between the inner vessel and the outer case; 13 - the first side hole in the shoulder (2, a), coinciding with the side hole (8) on the wall of the inner vessel; 14 - temperature sensor; 15 - heating element; 16 - an external heating element at the end of a sampling tube (11) passing through an opening (10) in the bottom of the outer casing (9); 17 - thermal insulation.

The state of the device before diving into the well is shown in FIG. 1. Previously, the entire device (outer case 9 and inner vessel 1) undergoes sterile preparation. The piston 6 is held by the permanent magnet 5 in the upper position. The inner vessel 1 and the outer casing 9 are filled with ultrapure water. Water through the hole 4 enters the side hole 12 in the shoulder (2, a) between the lid (2) and the edge of the inner vessel (1), which is necessary to ensure communication with the gap between the inner vessel and the outer casing, from where it goes through the holes 13 (in the shoulder) and 8 (the inner vessel) is poured into the inner vessel 1 and through the hole 7 (at the bottom of the inner vessel) it fills the outer case 9. At the same time, the outer end of the sampling tube 11 is closed during filling with water. After filling with water at the end of the tube 11 at the location of the heater 16 freezing Xia ice plug to the end of the sampling tube during the immersion was closed and remained clean the wellbore with the drilling fluid. The location of the ice plug on the heater 16 ensures its reliable retention. The hole 4 in the lid is closed with a stopper. The outer casing 9 is screwed to a drill pipe with a carrier cable. The conductive wires of the carrier cable are connected to the wires of the electric heaters 15, 16 of the temperature sensor 14 and the wires of the magnet 5. After that, the device is ready for immersion in the well.

The device is intended for sampling ice water, which comes from the lake to the lower part of the drilled well. The device does not descend into the ice lake for sampling water, which ensures the preservation of the ecological purity of the reservoir.

To prevent freezing of water in the device during immersion in the well when it passes cold drilling fluid with a temperature well below the solidification temperature of the water inside the outer vessel 9, thermal insulation 17 is located. The water temperature in the device during lowering is controlled by the temperature sensor 14, and its signal is turned on and turn off the heater 15.

After the device is delivered to the bottom of the well, which is filled with water from the lake, the heater 16 is turned on and the plug is melted at the end of the sampling tube 11. After the plug is melted, the magnet 5 is briefly energized, and the piston 6 with its own weight begins to sink inside the vessel 1, pushing it out of it ultrapure water through the hole 7 in the bottom of the vessel 1 into the outer casing 9 and sucking lake water through the sampling tube 11 through the holes 8, 13 and 12 into the inner vessel 1. Upon reaching the bottom of the inner vessel 1 Porsche 6 closes the hole 7 at the bottom of the inner vessel, and the process of water intake is completed. The sampler is ready to rise. The state of the sampler after taking a water sample into the inner vessel is shown in FIG. 2. When the device is in the well on the structural elements there are no pressure drops, which reduces the weight of the structure and allows you to lower the device on the carrier cable to great depths - several kilometers.

The temperature of the water in the device during the ascent is controlled by the temperature sensor 14, and by its signal the heater 15 is turned on and off, i.e. water does not freeze. Heaters 15 and 16 are turned on continuously until the sampler is removed from the well. After removing the sampler from the well, the electrical wires of the sampler are disconnected from the veins of the carrier cable, and the outer casing 9 is disconnected from the drill pipe with the carrier cable. The sampler is transferred to a clean room to extract lake water samples.

The operation of the device when removing water samples from it is shown in FIG. 3.

The sampling tube 11 is closed by a plug 20. A plug is removed from the hole 3 and the overflow tube 18 is immersed in it up to the piston 6. The tube 18 is connected with a flexible hose to a sterile container for the sampled water. A plug is removed from the hole 4 and a gas supply tube 19 is inserted into it. Ultrapure gas argon is supplied from the cylinder through the reducer to the tube 19 and squeezes water from the inner vessel 1 through the overflow tube 18 into a sterile water tank. After completion of the removal of lake water from the inner vessel 1, the tubes 18 and 19 are removed, and the holes 3 and 4 are closed with plugs.

Thus, the inventive device provides better water sampling since at the time of sampling excluded the ingress of drilling fluid from the outer walls of the device into the sampling vessel. The device does not descend into the ice-covered lake for sampling water, but is taken from the bottom of the well, which is filled with water from the lake, which ensures the preservation of the ecological purity of the reservoir.

Literature

1. Copyright certificate No. 1488717 "Device for sampling liquid samples from ice massifs". IPC G01N 1/10, publ. BI No. 23, 1989.

2. RF patent No. 2182225 "Thermoborer sampler". IPC G01N 1/02, publ. 05/10/2002.

3. RF patent No. 2244913. "A device for sampling from under-ice reservoirs." IPC G01N 1/10, G01N 1/02, publ. 01/20/2005. - prototype.

Claims (4)

1. A device for sampling water from under-ice reservoirs, including an outer casing located inside it to ensure tightness of the inner vessel for sampling the test water, heaters, holes in the outer casing and the inner vessel, the top of the outer casing having means for securing the lifting mechanism, and the hole in the bottom of the outer casing is intended for sampling the analyzed water, characterized in that the outer casing and the inner vessel for sampling water are installed with some clearance, and inside a piston with an electromagnet is mounted on the vessel for sampling water, and a hole is made on the side surface in the upper part of the inner vessel for the analyzed water to enter the vessel, another hole is made in the bottom of the inner vessel for draining the water into the outer case, the inner vessel having a lid with a collar hermetically covering the outer part of the inner vessel, and a lid with a collar mounted on the inner casing with an upper gap, and in the gap between the outer casing and the inner a tube is located at the oud, which is a sampling tube, one end of which is brought out to ensure tightness through a hole in the bottom of the outer case, the upper part of the lid of the inner vessel has two through holes with plugs, and a through vertical hole is made inside the flange of the cover along its entire height, which tightly enters the second end of the sampling tube, and two holes are made laterally from this hole in the collar towards the inner vessel, the first of which is aligned with the hole in the upper part of the inner vessel for entering the analyzed water sample, and the second hole in the shoulder is aligned with the upper gap between the lid and the edge of the inner vessel to provide communication with the gap between the inner vessel and the outer casing, and the heating elements are mounted on the outer part of the sampling tube and in the gap between the outer case and the inner vessel, the piston electromagnet and heating elements have wires brought to the ice surface of the reservoir. 2. A device for sampling water from under-ice reservoirs according to claim 1, characterized in that heat insulation is provided between the outer casing and the inner vessel. 3. A device for sampling water from under-ice reservoirs according to claim 1, characterized in that one of the holes in the upper part of the lid of the inner vessel provides ultra-pure gas, such as argon, to the inside of the vessel, and the other hole in the upper part of the lid of the inner vessel provides sterile removal of the selected test water sample from the inner vessel to the outside.

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