CN111594104A - Method for filtering and descending turbidity in narrow space in well - Google Patents

Abstract

The invention discloses a method for filtering and reducing turbidity in a narrow space in a well, which comprises the following steps of firstly, filling a filter material between two pipes to increase a filter channel in order to enhance the filtering performance of a system, thirdly, after gravel filling is finished, putting a submersible pump into the pipe to pump and shake the well, fourthly, sealing a well mouth by adopting cement, fifthly, after the implementation of a new multilayer filtering process in the well is finished, testing the new process effect by adopting pumping tests with different flow rates to verify the effect, the invention effectively filters and reduces turbidity of drill holes with large water outlet quantity but high muddy quality, the outlet water of the drill holes with muddy water is high, the outlet water quality of the drill holes with muddy water meets the water quality requirement, and the phenomenon that a water well with large flow rate cannot be used or discarded is avoided, saving the water resource developed under the condition of emergency water exploration.

Description

Method for filtering and descending turbidity in narrow space in well

Technical Field

The invention relates to the technical field of emergency drought-resistant water taking, in particular to a method for filtering and turbidity-reducing in a narrow space in a well.

Background

Underground water resources are the root of human survival and the basic guarantee of social production, and the key to reasonably and effectively develop and utilize underground water is how to find underground water and effectively exploit and utilize the underground water.

At present, in emergency drought-resistant water exploration projects all over the country, the phenomena that the water quality requirement of a large number of large-flow wells cannot be used or abandoned due to the fact that the conventional well forming technology cannot meet the water quality requirement often occur, and water resources developed under the emergency water exploration condition are greatly wasted.

The main reasons of water well effluent turbidity are as follows: firstly, the selected filter pipe has too large pores, so that the filtering function is poor, and the silt in the stratum is filtered out from the pores of the filter pipe; secondly, the emergency well generally adopts a down-the-hole hammer and pipe drilling process, and no filter layer is arranged outside the pipe; thirdly, the selected water outlet layer section is not reasonable.

Disclosure of Invention

The invention aims to solve the problems in the prior art and provide a method for filtering and descending turbidity in a narrow space in a well.

A method for filtering and descending turbidity in a narrow space in a well comprises the following steps:

the integral pipe string mainly comprises a settling pipe, a multi-layer filter and a well wall pipe, wherein the bottom of the settling pipe is blocked, the lowest part of the pipe string is used for gathering fine sand grains and rock debris which flow into a filter pipe through a filter layer in the well washing and water pumping processes to prevent the filter pipe from being blocked by sediment, the multi-layer filter is arranged at a water-containing layer position, and the well wall pipe is arranged at a water-free position and a well mouth in a stratum;

the lower pipe is connected by a lifting method, the connection mode of the well pipes is welding, the circumference of the well pipes is ensured to be upright during welding, centralizers are reasonably arranged according to a drilling structure and the position of a water-bearing layer, the arrangement intervals of the centralizers are about 30 meters generally, and the diameters of the centralizers are 40-50 mm smaller than the diameters of the drilled holes generally, so that the well pipes are kept centered in the process of pipe connection, a certain interval between the inner pipe and the outer pipe is ensured, and the subsequent gravel filling is convenient to be uniform;

step two, in order to enhance the filtering performance of the system, a filtering channel is added by filling a filtering material between two pipes, the framework filtering material is hard and clean quartz sand, in addition, activated carbon particles are doped into the quartz sand, the diameter of the activated carbon particles is 0.5-5mm, the median value of the particle diameter is 3mm, the volume ratio of the activated carbon to the quartz sand is 1:10, the particle diameter is determined according to the stratum condition, after a period of time, the particles of the filtering material are rearranged under the action of water flow, a graded filtering layer from thin to thick is formed along the water flow direction, the graded filtering layer is also called as a reverse filtering layer, and the effect of filtering in advance is achieved for the multilayer filter;

step three, after gravel filling is finished, a submersible pump is put in to pump water and shake and wash the well, when pumping water, the submersible pump is continuously stopped, shaking is formed in the well, silt in the well is pumped out, particles of the filter material and the water-containing layer section are rearranged, the purposes of filtering water and retaining sand are achieved, and meanwhile, the cleanness degree of the water sample is observed until the water is cleaned and sand is cleaned, and the pump is stopped;

step four, sealing the well mouth by adopting cement, preparing cement slurry with a water-cement ratio of 0.5, fully stirring for 15 minutes after the preparation is finished, slowly and uniformly pouring the cement slurry into the annular space until the surface of the ground, and sealing the well mouth;

when the conventional cement is solidified, the volume can shrink, and cracks are formed in annular gaps, so that the sealing effect is influenced, therefore, when cement slurry is prepared, sodium bentonite with the volume being 3% of that of the cement is added, and when the cement slurry is solidified, the volume cannot shrink, and the volume slightly expands, so that the sealing effect is fully ensured;

specifically, the purpose of well head sealing is to isolate the sediment of a well section with higher sediment content from entering a pumping well section, so as to influence the turbidity of outlet water, prevent surface water with poorer water quality from entering the pumping well section, fill fine sand in an annular space, and prevent cement slurry from permeating a filter material layer so as to avoid influencing the water yield;

step five, after the implementation of the new multilayer filtering process in the well is finished, adopting water pumping tests with different flow rates to test the effect of the new process and verify the effect;

specifically, the activated carbon particles are prepared by taking high-quality coconut shells as raw materials and carrying out fine processing through a series of production processes, are black and granular in appearance, have the advantages of developed gaps, good adsorption performance, high strength, economy, durability and the like, and have good purification and adsorption effects on impurities and muddy components in water;

specifically, when filling gravel, a bucket or other containers with known volume are used for containing filter materials, then the filter materials are slowly delivered into the holes along the periphery of the pipe, in the process of filling the filter materials, the height of the filled gravel is measured by a measuring rope at any time and is compared with the volume of the filter materials filled in the enclosing manner, if a filter material bridge plug is found, the enclosing of the filter materials is immediately stopped, the reason is analyzed, treatment measures are taken, and the gravel can be continuously filled until the bridge plug is completely treated, so that the filter materials are uniformly and compactly filled into annular gaps;

a multi-layer filter used in a method for filtering and descending turbidity in a narrow space in a well comprises a bridge type water filtering pipe, an annular baffle, a first bamboo curtain and a high-performance nylon net, the bamboo curtain comprises a second bamboo curtain, a plurality of first fixing bands, a plurality of second fixing bands and a plurality of third fixing bands, wherein the annular baffle is welded at the bottom of the bridge type water filter pipe, the first bamboo curtain is wrapped outside the bridge type water filter pipe and is fixed through the first fixing bands, the first fixing bands are uniformly arranged outside the first bamboo curtain, a plurality of layers of high-performance nylon nets are spirally wound outside the first bamboo curtain, the first bamboo curtain is completely wrapped through the high-performance nylon nets, the high-performance nylon nets are fixed through the second fixing bands, the second fixing bands are uniformly arranged outside the high-performance nylon nets, the second bamboo curtain is wrapped outside the high-performance nylon nets, the second bamboo curtain is fixed through the third fixing bands, and the third fixing bands are uniformly arranged outside the second bamboo curtain;

specifically, the annular baffle is used for protecting the nylon net and the bamboo curtain when the pipe is put down so as to prevent the nylon net and the bamboo curtain from being scratched and damaged;

the high-performance nylon net is a pp nylon net which has high toughness, good elasticity, corrosion resistance and no water pollution;

specifically, the rationale that three-layer filtration plays the purification performance is that the second bamboo curtain plays support and guard action to can filter the great sand of aquatic particle diameter, impurity etc. middle high performance nylon net mainly purifies the effect of the less granule in aquatic and silt matter composition, is the main filter layer of purification, and first bamboo curtain plays the middle filter screen of protection, prevents to be damaged by the bellied bridge of bridge type strainer and has great porosity effect.

The invention has the beneficial effects that:

the invention effectively filters and reduces turbidity of the drill hole with large water yield, high muddy water and turbid outlet water, so that the muddy water is high, the outlet water quality of the drill hole with turbid outlet water meets the water quality requirement, the phenomenon that a large-flow water well cannot be used or is abandoned is avoided, water resources developed under the emergency water finding condition are saved, the waste of the water resources is avoided, the basis of social production is ensured, and underground water resources are reasonably and effectively developed and utilized.

Drawings

FIG. 1 is a schematic perspective view of the present invention;

FIG. 2 is a perspective view of a filter used in the present invention;

FIG. 3 is a front view of a filter used in the present invention;

FIG. 4 is a cross-sectional view taken along line A-A of FIG. 4 in accordance with the present invention;

fig. 5 is a detailed view of the invention at B in fig. 5.

Detailed Description

Referring to fig. 1 to 5, a method for filtering and descending turbidity in a narrow space in a well includes the following steps:

the integral pipe string mainly comprises a settling pipe, a multi-layer filter and a well wall pipe, wherein the bottom of the settling pipe is blocked, the lowest part of the pipe string is used for gathering fine sand grains and rock debris which flow into a filter pipe through a filter layer in the well washing and water pumping processes to prevent the filter pipe from being blocked by sediment, the multi-layer filter is arranged at a water-containing layer position, and the well wall pipe is arranged at a water-free position and a well mouth in a stratum;

the lower pipe is connected by a lifting method, the connection mode of the well pipes is welding, the circumference of the well pipes is ensured to be upright during welding, centralizers are reasonably arranged according to a drilling structure and the position of a water-bearing layer, the arrangement intervals of the centralizers are about 30 meters generally, and the diameters of the centralizers are 40-50 mm smaller than the diameters of the drilled holes generally, so that the well pipes are kept centered in the process of pipe connection, a certain interval between the inner pipe and the outer pipe is ensured, and the subsequent gravel filling is convenient to be uniform;

step two, in order to enhance the filtering performance of the system, a filtering channel is added by filling a filtering material between two pipes, the framework filtering material is hard and clean quartz sand, in addition, activated carbon particles are doped into the quartz sand, the diameter of the activated carbon particles is 0.5-5mm, the median value of the particle diameter is 3mm, the volume ratio of the activated carbon to the quartz sand is 1:10, the particle diameter is determined according to the stratum condition, after a period of time, the particles of the filtering material are rearranged under the action of water flow, a graded filtering layer from thin to thick is formed along the water flow direction, the graded filtering layer is also called as a reverse filtering layer, and the effect of filtering in advance is achieved for the multilayer filter;

step three, after gravel filling is finished, a submersible pump is put in to pump water and shake and wash the well, when pumping water, the submersible pump is continuously stopped, shaking is formed in the well, silt in the well is pumped out, particles of the filter material and the water-containing layer section are rearranged, the purposes of filtering water and retaining sand are achieved, and meanwhile, the cleanness degree of the water sample is observed until the water is cleaned and sand is cleaned, and the pump is stopped;

step four, sealing the well mouth by adopting cement, preparing cement slurry with a water-cement ratio of 0.5, fully stirring for 15 minutes after the preparation is finished, slowly and uniformly pouring the cement slurry into the annular space until the surface of the ground, and sealing the well mouth;

when the conventional cement is solidified, the volume can shrink, and cracks are formed in annular gaps, so that the sealing effect is influenced, therefore, when cement slurry is prepared, sodium bentonite with the volume being 3% of that of the cement is added, and when the cement slurry is solidified, the volume cannot shrink, and the volume slightly expands, so that the sealing effect is fully ensured;

specifically, the purpose of well head sealing is to isolate the sediment of a well section with higher sediment content from entering a pumping well section, so as to influence the turbidity of outlet water, prevent surface water with poorer water quality from entering the pumping well section, fill fine sand in an annular space, and prevent cement slurry from permeating a filter material layer so as to avoid influencing the water yield;

step five, after the implementation of the new multilayer filtering process in the well is finished, adopting water pumping tests with different flow rates to test the effect of the new process and verify the effect;

specifically, the activated carbon particles are prepared by taking high-quality coconut shells as raw materials and carrying out fine processing through a series of production processes, are black and granular in appearance, have the advantages of developed gaps, good adsorption performance, high strength, economy, durability and the like, and have good purification and adsorption effects on impurities and muddy components in water;

specifically, when filling gravel, a bucket or other containers with known volume are used for containing filter materials, then the filter materials are slowly delivered into the holes along the periphery of the pipe, in the process of filling the filter materials, the height of the filled gravel is measured by a measuring rope at any time and is compared with the volume of the filter materials filled in the enclosing manner, if a filter material bridge plug is found, the enclosing of the filter materials is immediately stopped, the reason is analyzed, treatment measures are taken, and the gravel can be continuously filled until the bridge plug is completely treated, so that the filter materials are uniformly and compactly filled into annular gaps;

a multilayer filter used for a method for filtering and reducing turbidity in a narrow space in a well comprises a bridge type water filter pipe 11, an annular baffle plate 12, a first bamboo curtain 13, a high-performance nylon net 14, a second bamboo curtain 15, a plurality of first fixing belts 16, a plurality of second fixing belts 17 and a plurality of third fixing belts 18, wherein the annular baffle plate 12 is welded at the bottom of the bridge type water filter pipe 11, the first bamboo curtain 13 is wrapped on the outer side of the bridge type water filter pipe 11, the first bamboo curtain 13 is fixed through the first fixing belts 16, the first fixing belts 16 are uniformly arranged on the outer side of the first bamboo curtain 13, a plurality of layers of high-performance nylon nets 14 are spirally wound on the outer side of the first bamboo curtain 13, the high-performance nylon nets 14 wrap all the first bamboo curtains 13, the high-performance nylon nets 14 are fixed through the second fixing belts 17, the second fixing belts 17 are uniformly arranged on the outer side of the high-performance nylon nets 14, the second bamboo curtain 15 is, the second bamboo curtain 15 is fixed by a third fixing belt 18, and the third fixing belt 18 is uniformly arranged on the outer side of the second bamboo curtain 15;

specifically, the annular baffle 12 is used for protecting the nylon net and the bamboo curtain when the pipe is put down so as to prevent the nylon net and the bamboo curtain from being scratched and damaged;

the high-performance nylon net 14 is a pp nylon net which has high toughness, good elasticity, corrosion resistance and no water pollution;

specifically, the basic principle that the three-layer filtering structure plays a role in purification is that the second bamboo curtain 15 plays a role in supporting and protecting, sand, impurities and the like with large particle sizes in water can be filtered, the middle high-performance nylon net 14 mainly purifies small particles and sludge components in water and is a main filtering layer for purification, and the first bamboo curtain 13 plays a role in protecting a middle filtering net, preventing the bridge of the bridge type water filtering pipe 11 from being damaged and playing a role in large porosity.

Claims (1)

1. A method for filtering and descending turbidity in a narrow space in a well is characterized in that: the method comprises the following steps:

the integral pipe string mainly comprises a settling pipe, a multi-layer filter and a well wall pipe, wherein the bottom of the settling pipe is blocked, the lowest part of the pipe string is used for gathering fine sand grains and rock debris which flow into a filter pipe through a filter layer in the well washing and water pumping processes to prevent the filter pipe from being blocked by sediment, the multi-layer filter is arranged at a water-containing layer position, and the well wall pipe is arranged at a water-free position and a well mouth in a stratum;

the lower pipe is connected by a lifting method, the connection mode of the well pipes is welding, the circumference of the well pipes is ensured to be upright during welding, centralizers are reasonably arranged according to a drilling structure and the position of a water-bearing layer, the arrangement intervals of the centralizers are about 30 meters generally, and the diameters of the centralizers are 40-50 mm smaller than the diameters of the drilled holes generally, so that the well pipes are kept centered in the process of pipe connection, a certain interval between the inner pipe and the outer pipe is ensured, and the subsequent gravel filling is convenient to be uniform;

the multilayer filter comprises a bridge type water filter pipe (11), an annular baffle plate (12), a first bamboo curtain (13), a high-performance nylon net (14), a second bamboo curtain (15), a plurality of first fixing belts (16), a plurality of second fixing belts (17) and a plurality of third fixing belts (18), wherein the annular baffle plate (12) is welded at the bottom of the bridge type water filter pipe (11), the first bamboo curtain (13) is wrapped outside the bridge type water filter pipe (11), the first bamboo curtain (13) is fixed through the first fixing belts (16), the first fixing belts (16) are uniformly arranged outside the first bamboo curtain (13), the outer side of the first bamboo curtain (13) is spirally wound with a plurality of layers of high-performance nylon nets (14), the high-performance nylon nets (14) wrap the first bamboo curtain (13) completely, the high-performance nylon nets (14) are fixed through the second fixing belts (17), and the second fixing belts (17) are uniformly arranged outside the high-performance nylon nets (14), the second bamboo curtain (15) is wrapped outside the high-performance nylon net (14), the second bamboo curtain (15) is fixed through a third fixing belt (18), and the third fixing belt (18) is uniformly arranged outside the second bamboo curtain (15);

the high-performance nylon net (14) is a pp nylon net which has high toughness, good elasticity, corrosion resistance and no water pollution;

step two, in order to enhance the filtering performance of the system, a filtering channel is added by filling a filtering material between two pipes, the framework filtering material is hard and clean quartz sand, in addition, activated carbon particles are doped into the quartz sand, the diameter of the activated carbon particles is 0.5-5mm, the median value of the particle diameter is 3mm, the volume ratio of the activated carbon to the quartz sand is 1:10, the particle diameter is determined according to the stratum condition, after a period of time, the particles of the filtering material are rearranged under the action of water flow, a graded filtering layer from thin to thick is formed along the water flow direction, the graded filtering layer is also called as a reverse filtering layer, and the effect of filtering in advance is achieved for the multilayer filter;

step three, after gravel filling is finished, a submersible pump is put in to pump water and shake and wash the well, when pumping water, the submersible pump is continuously stopped, shaking is formed in the well, silt in the well is pumped out, particles of the filter material and the water-containing layer section are rearranged, the purposes of filtering water and retaining sand are achieved, and meanwhile, the cleanness degree of the water sample is observed until the water is cleaned and sand is cleaned, and the pump is stopped;

step four, sealing the well mouth by adopting cement, preparing cement slurry with a water-cement ratio of 0.5, fully stirring for 15 minutes after the preparation is finished, slowly and uniformly pouring the cement slurry into the annular space until the surface of the ground, and sealing the well mouth;

when the conventional cement is solidified, the volume can shrink, and cracks are formed in annular gaps, so that the sealing effect is influenced, therefore, when cement slurry is prepared, sodium bentonite with the volume being 3% of that of the cement is added, and when the cement slurry is solidified, the volume cannot shrink, and the volume slightly expands, so that the sealing effect is fully ensured;

and step five, after the implementation of the new multilayer filtering process in the well is finished, adopting water pumping tests with different flow rates to test the effect of the new process and verifying the effect.

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