When the column that holds the wellbore wall in an unaltered state, ceases to perform its functions, the question inevitably arises as to pull the pipe out of the hole with the least amount of effort and finances. In this case, use a number of ways. All of them involve the use of specialized equipment.
In the article presented by us are described in detail proven methods for extracting the casing from the water intake generation. Presents problems that may be encountered when pulling a pipe string from the bore. Taking into account the recommendations of our problem will be solved with the least effort and time.
The content of the article:
- What is the casing?
- When you need to extract the casing?
- What factors should be taken into account?
- List of related problems
- Preparations for dismantling the well bore
Methods for removing the pipe from the well
- Method for tensioning extraction column
- Extraction washing method
- Application of the method of unwinding
- Commercial and home equipment
- Conclusions and useful videos on the topic
What is the casing?
Well - the same well, but very deep and small diameter. To strengthen the wall and provide tightness well design used casing. If there are several layers of water unfit for human consumption, the casing does not allow mixing them with clean drinking water in the soil.
The use as casing pipe of metal, plastic, and asbestos. The first of them strong, well withstand mechanical loads. Release them with a diameter of 114 to 508 mm. They are equipped with thread, which facilitates their assembly and disassembly.
The main disadvantage - the tendency to corrosion and high cost. They are used mainly for deep mines with more water resources.
Borehole with steel casing in case of need can be restored. If the column is made of another material, with recovery tool for drilling impossible
Devoid of the disadvantages of steel pipes, plastic products. Inner diameter PVC pipe of 80 to 200 mm. Products also have threads, chemically stable, easy. Bury plastic pipes are not more than 60 m.
Strength properties and the cost of plastic siege towers have optimal ratio. The disadvantage - low resistance to mechanical stress. Ideal for decorating the well in the backyard
Asbestos-cement pipes having a diameter of 10 - 50 cm and a length of 500 cm. Use them less and less. They are fragile and unsafe for health.
When you need to extract the casing?
Reasons for removing the casing from the borehole essentially only three:
- An barrel decompression that occurs due to faulty connections or links of casing pipes rust corrosion.
- hopelessly jammed tools or equipment in the trunk, which is why it is impossible to remove the old pump and install a new one.
- Requires changing the tubular well construction: the deepening of the transformation well screen etc.
The remaining cases are not a reason for the structure extraction. Sometimes it is possible to save the situation by setting a suitable polymeric liner diameter. If there was a break at a great depth, dismantling is simply impossible. Then easier to drill a new source, you spend a lot of money to restore the old.
The easiest way to remove the casing from the borehole, during the development of the water source. This is what happens if the barrel falls nevyburivaemy tool or twisted. Extraction is carried out in the reverse order of installation
The hardest thing to get out of the land of the old casing, issyakshey well. Typically, the trunk in such situations simply tamponiruyut - covered with soil without removing the pipes
Sense disassemble two upper casing unit is, if, for example, submersible pump stuck at the top of the barrel. In this case, the pipe clamp is fixed and pulling it through the hydraulic
If the disposal of the owners of the well no equipment with hydraulic systems, it is necessary to take advantage of the block structure that is connected to a mechanical winch
Removing the casing in the process of development
Dismantling of an old water well
Disassembly of the two upper links
Using blocks in the pulling pipes
What factors should be taken into account?
Usually well drilled on site to a great depth, so removing it from the casing - case from easy.
Before deciding on such action is necessary to clearly know the answers to the following 6 questions:
- which is made from a casing;
- weight of the product;
- how deep is its foundation;
- how much time has passed since its inception;
- the conditions under which exploited;
- if there is enough compelling reason why it should be removed.
Perhaps the demolition work will be so complicated, time-consuming and costly in financial terms, that rationality is not solved the question of how to easier and faster to get the pipe out of the well, and to abandon the idea in favor of a decision on a new source device water.
List of related problems
In the process of extracting the casing from the ground may be encountered with a number of unpleasant surprises. We must be prepared in advance to ensure that prepared the block and winch with the task can not cope due to insufficient traction. Then it is necessary to order the crane, and it will add more problems: we need a check from what the landscape will suffer inevitable.
It is necessary to take into account the time that the tube may be so "tightened" soils that have reduce the friction coefficient by drilling boreholes around the tip and filling them in a large of water. pipe will more easily from moist earth. A side effect of such actions - the probability of collapse of the mine walls.
When removing the casing constructions do without special equipment. By constructing it durable flooring rails or bars of rolled metal
Insufficient rigidity recoverable tube. If it is made of asbestos, the recess of it without damage can be no question.
She will simply fall apart and come to the surface in the form of separate fragments and fragments will be at the bottom of the well. It is better not to use such a mine again, if it is removed from the pipe of asbestos, given that this stuff is not safe.
Preparations for dismantling the well bore
Aware of possible difficulties, it is necessary to prepare for the process thoroughly.
The first step - determining the weight of the product, for which:
- measured well depth, pipe diameter, wall thickness;
- open guide and, guided by the diameter and wall thickness, are by weight 1 running. m;
- multiplied by the value found in the mine depth and receive the desired mass of the tube.
This value will base the choice of the winch on the traction force. If the figure has turned solid and winch with a pulling force does not exist, the only way - to order the crane. When the deviation of the calculated values of insignificant suitable conventional winch.
Methods for removing the pipe from the well
Professionals have their own methods of pulling the casing: the stretch followed by a cliff, with reciprocating washing, wringing.
Method for tensioning extraction column
To use this method you need a traveling system or jack. The force which arises during stretching, above the critical plasticity limit of the material casing. Therefore, the structure can not sustain and burst.
process algorithm is as follows:
- Around the mouth of the pipe dig a trench depth of about 1 m.
- They put on the pipe clamp, and the cables attached thereto, whereupon the design slightly tensioned.
- Clamp, which is attached to the cable, move the lower and repeat the same steps. It provides a smooth draw.
- The upper edge of the casing structure is stretched until breakage. Fragment recovered from the mine, and the remainder of capture special fishing tool and the process is continued or after replacing the damaged portion of the barrel casing is set on a former a place.
Variant are useful for the dismantling of pipes having a large diameter and thick wall.
Extract this method the entire line is almost impossible. Most often, the tube will not be suitable for further use
If the borehole axis has a vertical deflection extraction method can not be used. For such a complex work better to hire a drilling crew.
It looks like a mechanical grip - a collar, whereby the fixed pipe. The extraction process may complicate the failure and jam riser, so you need to take into account the plasticity of the material
Hoist used for lifting should be a large load capacity. The best option - the use of jacks. You should know that to count on the continued application of the recovered pipe is not necessary.
Extraction washing method
If the casing is not coming out of the ground due to the formation of sand plug to release and remove it using a relatively simple way - washing and stretching. For this you need a pump with a special device for washing. The pressure of the pump is connected to the top tube.
The pressure should be minimal, but sufficient for the water circulation. The column was washed, and after going sand, the pressure is increased. walk around the pipe body by scrolling it with the rotor and shaking. All this is done in parallel with the washing. Thus, reduce friction, and column will be released from the well easier.
Ideally, the diameter of the pipe can not only fix the pump at the top, but also omit the second column to the bottom. The reverse flow of water is started as soon as the hose edge for washing drops below the shoe-coupling sedimentary column at 300 cm. The process is continued until complete elimination of sand around the pipe mash.
Sometimes when lifting tube to 10 m becomes impossible its extraction because of the strong seal plug. In this case, one way out - to remove the fragments. Separately should stay on the process of extraction pipes.
First on her body is welded fittings segment diameter of about 18mm. This element is necessary in order to secure the winch straps and begin lifting the riser casing oscillator.
For lifting must be applied vertically directed tractive force. For this purpose, at the highest point of the pipe retrievable operate mounting block, and the cable being moved therethrough. When the winch drum rotation torque conversion occurs in towing force.
Tube light weight, you can use the lever. Its end is fed under the weld reinforcement and applying pressure, slowly pull the riser from the ground.
Application of the method of unwinding
Using this method allows to unscrew casing elements and to remove them from the wellbore.
For application of the method requires the supply of tools:
- Fishing crown;
- komulyativnye torpedoes.
A fishing crown special left-hand thread and a steel drill pipe is lowered into the shaft. the rotor is rotated through the pipe counterclockwise.
Having made approximately 20 revolutions operate reciprocating casing, increasing the load to a maximum. If you catch a tube is not cut off, and the unwinding of reciprocation is repeated. The result of these efforts must be unscrewed incomplete connections.
Devices for catching tubes equipped or helical collet grippers. The diameter of the pipe should be harvested smaller diameter casing Trubolovki
If the thread failed to weaken even after a number of cycles, in turn allowed special tool which rotating force to oscillate pipe due to friction and the torque transmitting the extracted standpipe.
Result: after rotation of the tool 1 for compound chasa shaken. In the next stage the upper rim capture column and unscrewed fragment thereof. To extract otkruchennuyu of the tube outwardly, the tensile force is applied. Action is repeated until the whole column will not be dismantled and all its elements will be at the top.
untwisting process based on a combination of load torque and tensile force. Untwist first casing riser, and after taken out. What would the column was cut short, torque and tension force necessary to constantly monitor
When all the efforts are not successful, use a radical method - a violation of integrity of the structure through the use of cumulative torpedoes. As a result of an explosion at a predetermined depth in the body of the pipes appear circular cuts. It remains to cut individual elements by means of the punch or other cutting tool.
All of these works under the force of the specialized organizations. The cost of their considerable, so the self-extracting pipe owners of country houses are looking for other ways.
Commercial and home equipment
To remove the casing from a deep well apply professionals prefabrication equipment.
Characterized by its nominal parameters such as the pressure in MPa, stroke effort - forward and reverse in the mc, maximum torque kN / m, the greatest clamping force or a recovery are, angle clamps, weight in kg, dimensions in mm diameters range extractable pipes.
The installation consists of a baseplate mounted thereon stationary gripper and two hydraulic power cylinders, the upper plate, the movable grip by which the tube is clamped
Rods of cylinders with hydraulic return combined support equipped crosspiece, which supports the upper plate. To clamp the supporting column on this plate there is a special movable grip. As the fixed and movable jaws are wedge-3 cams having an internal cuts and placed in the holder.
Hydraulic cylinders connected to a pumping station. In case of abnormality, when the extraction tube is not enough force is used wedging clamp device. Tension may be insufficient in the case where due to unforeseen circumstances, there are additional frictional forces between the tube body and the borehole wall.
The equipment is mounted on the casing and clamp the rack, with the aid of mobile capture, and then rousing. The rise is equal to the piston stroke. The next step - fixing tube fixed grip and a top plate return to its initial position. The tube is removed by repeating these steps. In the process of drawing the riser support it by crane.
With such equipment is pulled out of the ground casing, the top of which is almost invisible, ie. K. A low pickup setting. Another advantage of the mechanism - the ability to raise steel pipes, which are various in wide ranges.
To disassemble the tube small-diameter portion at its suitable equipment can be made independently. Required for this two channel bars for uprights, cable drum, the bearing inside diameter 40 mm, rope handle.
Make two supports height of about 1 m and a width of about 0.6 m. They have the shape of the letter T in the inverted form. At the top of the posts to secure the bearing, and the axis passes through it. On the axis of the drum and the fixed handle.
Cable cover tube and begin to rotate the drum. Pipe gradually emerge from the soil. If dismantling is subject to the plastic article, use the special clip.
As the extraction pipe is lowered below the rope. When the structure is of considerable length, use a special device - Chalco, to keep the column by moving the cable to the new position.
Conclusions and useful videos on the topic
Video # 1. Video author withdrew the process of removing the casing PVC pipe:
Video # 2. Tools and equipment for the extraction of the casing:
Depending on the financial capacity and availability technique can use any means to retrieve the pipe. It is important to be careful not to neglect safety. Perhaps after all the calculations you decide that it is better to lay a new well.
If you had to drag the casing of the wellbore, tell us how it was possible to remove it. Share information that can use site visitors in similar situations. Please write comments, ask questions, leave the posts with his own views on the proposed contact material and pictures.