Reasons for the appearance of sand in the well. Methods for removing bulk mass from a mine. How do I flush, purge, and prime the source? Sand cleaning from a well is the process of removing accumulated bulk mass from a mine to restore the functioning of the source. The procedure is complex and requires special devices and mechanisms. This article will show you what to do if sand is coming out of the well.
The main reasons for the appearance of sand in the well
A large amount of free-flowing mass most often appears in the wells on the sand. The problem is related to the peculiarities of this aquifer, consisting of oversaturated sand, surrounded on all sides by a clay shell.
Dirt will penetrate into the trunk anyway, but the rate of its accumulation depends on several factors:
- If the soil particles in the aquifer are very small, the filter will not be able to capture them. Protective devices usually have holes with a diameter of 3-5 mm, which only stop large elements.
- Soil can enter the wellbore from the surface due to the lack of waterproofing of the casing head.
- Once the protective device is destroyed, nothing can hold the soil at the entrance to the well. If the problems are related to the filter, it will not be possible to solve the problem by replacing it, you will have to drill a new shaft.
- The appearance of gaps between the casing elbows through which dirt enters. This is due to a violation of the technology for building a well. Slots are formed if during installation the elements are not turned over or the joints are not sealed.
- When the soil moves, the trunk is also clogged with sand.
- Deviation from the process of installing the filter can cause contamination of the source. If the device is lowered into the casing after it has been installed, the bottom of the casing will be smaller in diameter and will be left without circulation. The constantly arriving sand will not be removed with water and will soon fill the intake cavity of the trunk.
- The source is polluted in case of intermittent water intake. Often, summer residents encounter such a phenomenon when they return to the site in the spring. During the winter months, the water veins are able to deposit enough soil into the well to reduce the flow rate of the well.
The source can be easily cleaned at the initial stage of contamination without the involvement of specialists. It is necessary to think about removing dirt from the well, if you find that the pressure in the water supply system has noticeably decreased, sediment remains in the bucket, and the faucet gives out water in portions, along with air.
Methods for cleaning a well from sand
If sand comes out of the well, one of the methods of getting rid of dirt is used - pumping, flushing or blowing (with air). Each option applies in specific cases. In order not to be mistaken with the choice of method, study the information given in the table:
|Cleaning method||Necessary accessories||Application|
|Blowing||Air compressor||Immediately after drilling|
|Single pump flushing||Vibrating pump||Cleaning of shallow (up to 10 m) wells|
|Flushing with two pumps||Centrifugal pump and external water pump||Deep well cleaning|
|Impact rope method||Bailer, tripod and lifting mechanism||Coarse cleaning of heavily contaminated sources|
|Bubbling||Air compressor and motor pump||Well cleaning if there is a risk of damage to the screen and casing|
|Pumping||Fire engine||If you need a quick resuscitation of the source|
Sand contamination of a well can be prevented by adhering to the following rules:
- Thoroughly flush the shaft with high pressure water from the surface after drilling.
- To prevent sand from entering the source through the neck, install or build a caisson or a house above it.
- Install the water raising device according to the manufacturer's recommendations.
- Do not use a vibratory pump to continuously pump out water. This type of device facilitates the penetration of large quantities of sand into the wellbore.
- Pump several buckets of water out of the source every day to prevent dirt from accumulating at the bottom. If it is rarely used, pump out at least 100 liters of water every 1-2 months.
How to clean sand from a well?
Finding out why sand is coming out of the well is not easy. Contamination of the source is usually complex, therefore, it is often necessary to alternately apply different methods of cleaning it to achieve the desired result. Consider a few of the most commonly used technologies for removing bulk material from a mine, which can be used without the involvement of professional drillers.
Using a bailer for cleaning a well
The most effective way to clean sand from a well is to use a bailer. It is a hollow cylinder with a valve through which dirt enters and is removed with the tool outside.
For the procedure, you will need a device, the outer diameter of which is less than the inner diameter of the casing by several millimeters, and about 1 m long. Do not use too short because of the danger of skewing and jamming. Long products are very heavy and are designed for drilling. For lifting, an eye is welded to the device, to which the rope is tied. A cylinder filled with mud is heavy and difficult to lift to the surface. For this purpose, a tripod is used - a structure made of logs or pipes that can withstand a lot of weight. It is made from beams with a diameter of 15-20 cm.
The whole sand removal process goes like this:
- Assemble the tripod in the form of a pyramid and secure the beams at the top with nails or staples.
- To prevent the legs from moving apart, connect them together with slats.
- Secure the lifting hook to the top of the unit.
- If you have a house or a canopy over the well, disassemble it.
- Place the tripod over the neck, visually positioning the top over the center of the shaft.
- Hang the winch to it, and attach the thief to the chain. Lower the tool down with the mechanism and make sure it moves exactly in the center of the barrel.
- If necessary, move the device so that the thief is exactly in the center of the well.
- Dig in your feet to 0.7-0.8 m and secure the tripod from moving.
- Place the thief in the shaft and release the winch. After hitting the bottom, it will enter the ground to a certain depth. The sand will open the valve and go inside the thief.
- Raise the tool 50-70 cm. The valve will lower under the weight of the dirt and close the inlet.
- Throw the thief to the bottom until the cylinder is full of dirt.
- Pull the fixture to the surface with a winch, remove the sand from it and throw it back into the mine. The procedure lasts until all the sand is scooped up from the source.
Using a sand removal pump
Before cleaning the well of sand, buy household vibration pump type "Kid" or "Spring". The product has less power than a circular apparatus, but it costs much less. This fact is crucial when choosing a device for pumping water, because solid particles can damage it.
Not all products are suitable for work. The pump must take water from the bottom, work with thick slurry and raise even small pebbles to the surface, which are full at the bottom.
First, lower the device to the bottom several times and lift it up to shake up the dirt. Fix it at a height of 2-3 cm from the bottom, in the middle of the opening, and then turn it on.
The vibration pump can work continuously for half an hour, then it must be turned off to cool down and raised to the surface to get rid of dirt. It is easy to remove the pebbles under the valve: put the product in a container with clean water and turn it on, it will clean itself.
Small particles will quickly destroy the rubber valve, so be prepared to replace it. The part is inexpensive and can be purchased without any problems. The water in the well can be shaken with metal pin with welded nuttied to a long rope. It must be thrown down and then raised sharply. The raised sand will be pumped out by the pump to the surface together with water. If the product cannot be placed close to the bottom, for example, due to the presence of an internal filter with a diameter smaller than the casing pipe, use a long rubber tube. Secure it to the inlet flange with a hose clamp and insert the metal pipe inside. Fix the pump so that the tube almost touches the bottom and turn it on.
The cleaning procedure can be delayed due to the low power of the device. For the same reason, it will not be possible to clear a deep (more than 10 m) mine. But this method is very popular due to the simplicity of the technology and the lack of physical work.
Not everyone knows what to do if there is a large amount of sand in the well. The task is solved with the help of a single, but very powerful high capacity pump … Fire engines are equipped with similar pumps. Lower the pipe through which water will be supplied into the trunk, securing it at a distance of several centimeters from the bottom. Connect the hose of the fire truck to it. After turning on the pump, the flow will wash out the sand and bring it to the surface. This option can be used if the casing has thick walls and the filter is very durable.
Sand removal with two pumps
A deep well is cleaned simultaneously with two pumps - centrifugal and water pumpthat is on the surface. The vibrating pump is not able to raise water to a great height, and the pump is necessary to erode the sand layer. It is allowed to use a product that has already been installed in the well. It will take several hours to remove all the sand. The work is done in the following sequence:
- Lower the supply hose from the pump next to the unit located in the well and place it on the bottom.
- Pull the suction to a large container of clean water.
- Lead the hose from the centrifugal pump into the same tank.
- Turn on both products. A strong stream of water will wash away the dirt and mix with water, and a centrifugal pump will lift the slurry to the surface and direct it to the sump.
In the tank, the mud will sink to the bottom, and the purified liquid is pumped back into the well. During the procedure, periodically remove the loose mass accumulated at the bottom of the tank. Wiggle the hoses constantly to avoid clogging.
Removing sand from a well with an air blower
In all of the above options, a large pressure is created in the area of the filter from the flow of water or the bailer, which can lead to damage to the protective element or bursting of the column. Sand cleaning from wells using gas-air mixture absolutely safe for the source and its elements.
For work, you need to rent an air compressor and a surface pump. Lower the hose from the motor pump to the bottom. In the layer of sand at the bottom of the source, stick a special sprayer with a hose, which is connected to the blower. Cover the column head with a nozzle to drain water into the sump. Switch on both units. Air bubbles will capture grains of sand and lift to the surface, and then into the sump. The water in the tank will be cleared, and the pump will again direct it into the barrel. This method removes all the sand from the bottom, but the process can take several days or even weeks.
To remove the bulk mass, the well can be blown compressed air … The procedure is carried out immediately after the end of drilling to remove soil that the working tool could not remove from the mine.
For the operation, you will need a compressor capable of creating a pressure of 12-15 atmospheres. Before the procedure, connect the hose to the unit and lower it to the bottom of the barrel. After turning on the blower, the air will start blowing water together with sand from the well. When the water runs out, take a break to accumulate liquid and turn on the blower again. Work stops when clean water flows from the neck. The duration of the operation cannot be determined in advance; it can take many days.
How to clean a well from sand - watch the video:
The article describes in detail how to clean a well from sand with your own hands if you have the appropriate devices and mechanisms. The result will depend on how correctly you chose the method of removing the bulk mass from the bottom of the source, so be sure to study the features of each method before starting work.