JPH06322795A - Pumping-up method for underground water to be pressurized from group well attended with water injection - Google Patents

Abstract

PURPOSE:To increase water injection ability and pumping-up ability with a time by a method wherein refuse and a contaminating material needing monitoring, contained in injection water, are removed, and during water injection, water injection ability is increased by means of a vacuum deaerating device, all of a well group forms a well used for both water injection and pumping-up, and water injection and pumping-up are repeated in a given order. CONSTITUTION:A floating material contained in precipitation (a) and surface water (b), collected in a water collection passage 1, is removed by a screen 2 and mixed soil is removed by a filtering device 3, and water passing therethrough is stored in a first tank 4. It is decided by a water quality measuring device 5 whether each of water qualities, needing monitoring, of stored water exceeds allowable concentration. When concentration of any water is below an allowable concentration the water is caused to pass through a vacuum deaerating device 7 to remove gas dissolved in water. A water injection well is determined, in an order, decided on a basis of the magnitude of a quantity of water injected for a time in which an injection wall level (e) in each well 17 at a current point of time is increased to an upper limit water level (d). When a water level in a water injection well is increased to the upper limit water level (d) through injection of water, injection of water is stopped and water injection is transferred to a well 17 in a next order.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for pumping pressurized groundwater from a group of wells accompanied by water injection.

[0002]

2. Description of the Related Art The development of a submersible pump has made it possible to use a large amount of low-temperature, pressure-controlled groundwater with good water quality, which could not be used because the groundwater level was deep, at a low cost at any time. However, that would lead to the extraction of large amounts of stagnant groundwater,
Depletion of groundwater resources, occurrence of land subsidence, and invasion of seawater into aquifers in coastal areas resulted in pumping failures.

As one of the countermeasures, a method of injecting precipitation or surface water into a confined groundwater layer from a well has been attempted, but generally, the maximum amount of water injection is 60 to 80% of the immediately preceding amount of pumped water, and The amount decreased sharply as the aquifer clogged. In some cases, wells in contact with fault crush zones and underground water systems, which are exceptions, have been injected satisfactorily, but in this case as well, the wells were clogged with water and frequent backwashing operations were required. In addition, these water injections do not monitor water quality or remove contaminants.

[0004] When pumping groundwater under pressure in the target area with a group of wells, a pumping method of automatic switching that takes into account the pumping capacity and water quality at the time of trial drilling in each well, and the temperature of the two wells used as a pumping / irrigation well There are methods for underground storage of different types of surface water for use, but it is necessary to repeat water injection and pumping for all group wells in the target area, and to adjust the water injection capacity during water injection and the change over time in the water pumping capacity during pumping. In addition, automatic switching water injection and pumping methods based on the comparison results of all wells are not provided.

[0005]

[Problems to be Solved by the Invention] In order to make it possible to easily inject a large amount of precipitation and surface water in a target area into a general confined groundwater well group, dust, sediment, and monitoring pollution required for water injection are included. The substances are removed, and when water is injected, a vacuum degassing device is installed to increase the water injection capacity, and all of the wells are used as wells for water injection and pumping. By repeating the method of water injection or pumping in the order of the wells in the best condition, the water injection and pumping capacity of each well will be increased over time.

In the area targeted by this operation, it is possible to inject water in an amount of 60 to 80% or more of the pumping amount immediately before in any well. In addition to the annual rainfall of about 1.6 million m ³ per ha in the target area, the total amount of surface water that can be acquired is used as groundwater resources, and they can be used in any amount at any time, and It aims to significantly suppress pumping failures such as depletion of groundwater due to pumping, ground subsidence, and seawater intrusion into aquifers in coastal areas.

[0007]

According to the present invention, precipitation in a target area is collected in a water collection channel, surface water that can be acquired in the area is also guided to the water collection channel, and the surface water is suspended in these water at the end of the water collection channel. The substance is removed by a screen, the soil particles mixed in next are removed by a filtration device, the passing water is stored in the first tank, and a part of the water in the first tank is contaminated with the predicted pollutants requiring monitoring. When the concentration of any of the substances exceeds the set concentration specified for each water quality, the water quality of the water in the first tank is treated with a removal device, and it is confirmed that it is below the set concentration. The confirmed water was transferred to the second tank, and the water in the first tank that was below the set concentration or the second that was set below the set concentration
The water in the tank goes through the vacuum deaerator as quickly as possible, and then is poured into the water injection well through a pipe that has an outlet at a position lower than the lower limit water level specified for each well. It is a dual-use well for water injection, and the upper and lower water levels are set for each well.The order of the water injection wells is based on the large amount of water that can be injected until the well water level at the time of injection into each well reaches the upper water level. , When the water level of the water injection well reaches the upper limit water level, water injection is stopped, the water injection is moved to the next well, and the order of pumping is that the well water level at the time of pumping is the lower water level. Based on the large amount of water that can be pumped up to, the pumping will be stopped when the well level reaches the lower limit, and pumping will be moved to the next well.

The aquifer used by each well may be the same or different, but water injection and pumping are performed in different wells.

A method for pumping groundwater under pressure from a group of wells with water injection, which comprises the above method.

[0010]

[Operation] Precipitation collected in the water collection channel and suspended matter contained in the surface water are removed by the screen, and mixed sand, clay, colloids, etc. are removed by the filtration device, and the water passing through these is stored in the first tank.

Whether or not the stored water is above the set concentration for each monitored water quality is clarified by the measuring device. The set concentration shall be an arbitrary concentration below the allowable concentration specified by law for each water quality. When all the concentrations are below the set concentration, the water dissolved in the water is removed through a vacuum deaerator, and the amount of water that can be injected until the well water level at each point reaches the upper limit water level. The water injection wells will be determined in the order based on. The amount of water that can be injected is calculated from the correlation between the amount of water injected at the time of the last injection and the well water level, as shown in Figure 2.

[0012] The above operation is to inject precipitation and surface water having no problem in water quality from a well where a larger amount of water can be injected under the condition that clogging is least likely to occur. In addition, by targeting the well water level immediately before water injection, it is possible to make judgments in consideration of changes in the water injection capacity of the well caused by water injection and pumping in the surrounding wells.

When the water level of the water injection well reaches the upper limit water level, the water injection is stopped and the water injection is moved to the well in the next order.

When any one of the monitored water qualities of the water in the first tank exceeds a set concentration, the water is stored in the second tank through a removing device according to the water quality.

A part of the water in the second tank is sampled and the concentration of the water quality to be monitored is measured. When any concentration falls below the set concentration, the water is sent to a vacuum deaerator, and thereafter the same as above. Water by the method.

When the water in the second tank exceeds the set concentration for any of the monitored water qualities and it is likely to be suitable for water injection in the water quality removal again, the water in the second tank is returned to the first tank. After that, it is stored in the second tank through the removing device, and thereafter, the above operation is performed. When you don't have the chance,
Dispose of in the surface drainage.

When a demand for pumping water arises, pumping wells are determined in order based on the amount of pumpable water until the well water level of each well reaches the lower limit water level.

As shown in FIG. 2, the pumpable water volume is obtained from the correlation between the well water level and the pumped water volume shown at the time of the last water injection for each well. By targeting the well water level immediately before pumping, it is possible to make judgments in consideration of changes in the pumping capacity of the well caused by water injection and pumping in the surrounding wells.

When the well water level reaches the lower limit water level by pumping water from the pumping well, the pumping is stopped and the pumped water is transferred to the well in the next order.

By the above operation, the pumping can be carried out within the range where the pumping efficiency is the best and the pumping failure is less likely to occur.

In each well, the pourable amount until the well water level reaches the upper limit water level and the pumpable water amount up to the lower limit water level at any given point change with time during repeated operations of water injection and pumping. Therefore, when injecting or pumping water, measure the well water level and the amount of water injected or pumped during that time, and set them as the well water level necessary to set the possible amount of water injection or pumping for the subsequent well water level. , It has a function to automatically incorporate a new correlation to the water injection amount or pumped water amount.

By repeatedly using the above-mentioned water injection / pumping methods, the void structure of the stratum around the well is subject to repeated backflow operations, which not only makes it difficult to cause clogging,
We will expand and develop water channels around the wells and increase the water injection capacity and pumping capacity of the wells over time.

[0023]

[Examples] The necessary equipment and facilities are first provided in the target area with a water collection channel 1 for collecting precipitation a therein and introducing surface water b which can be acquired. A screen 2 and a filter device 3 are provided at the end of this water collection channel, and the water that has passed through is stored in a first tank 4.

From the first tank 4, a pipe 6 connecting between the measuring devices 5 for water quality to be monitored, a pipe 8 connecting to a vacuum degassing device 7,
Pipes 9 from the first tank 4 Each monitoring device 1 for water quality to be monitored
It reaches 0 and reaches the second tank 11 from this removing device through the pipe 12.

From the second tank 11, a pipe 13 connecting the measuring device 5 for water quality to be monitored and a pipe 1 connecting the vacuum degassing device 7 are connected.
4. Provide a pipe 16 to the drainage channel 15.

Each well 17 has a water level gauge 18 and a pump 1
9. A water injection pipe 20 is provided, and the water injection pipe 20 has a depth equal to or lower than the lower limit water level c set for each well, and 21 connected to the vacuum degassing device 7 at the upper end is a pumping pipe.

In each well 17, the upper limit water level d and the lower limit water level are set to c based on the correlation as shown in FIG. 2 in which the water level due to pumping or water injection and the change over time in the amount of water pumped or water injected are shown in the results of the past pumping test. To do.

The upper limit water level d is an arbitrary regulated water level that is lower than the well water level at which the rate of increase of the well water level e due to the injection of a unit amount of water increases rapidly, and the lower limit water level c is the pumping of a unit water amount. The water level is arbitrarily defined as a water level higher than the well water level at which the rate of decrease of the well water level e rapidly increases.

Since the above-mentioned correlation between the unit water injection amount or unit pumped water amount and the rate of change of the well water level e is changed due to the change of the groundwater flow structure of the aquifer f due to water injection or pumping,
A new correlation is sought each time pumping or water injection is performed.

Control of surface water flow into the water collection channel 1, measurement of water in the water collection channel and water quality of the first tank 4 and second tank 11, removal of contaminated water quality of water in the first tank 4 and the second tank 11. An automatic management device for automatically managing the control of the water injection operation, the selection of the pumping well and the injection well according to the water level of each well 17, and the time setting of the pumping and the water injection are provided.

[0031]

By carrying out the method of the present invention,
In order to make it possible to easily inject a large amount of precipitation and surface water in the target area into a general confined groundwater well group, remove the dust, sediment, and pollutants required for monitoring, etc. By providing a vacuum degassing device, the water injection capacity can be improved, and all of the wells can be used as both water injection and water pumping wells. By repeating the method of injecting or pumping water in order, it is possible to increase the water injection capacity and the water intake capacity of each well over time.

Further, in the target area of this operation, the water injection amount of 60 to 80% or more of the pumping amount immediately before can be applied to any of the wells. Therefore, in the target area, the annual precipitation per ha is obtained. in addition to the approximately 1.6 million m ^3, the total amount of surface water that can be acquired with groundwater resources, they will be available in any amount at any time, and groundwater based on the pumping depleted reduction and subsidence , It is possible to significantly suppress pumping obstacles such as seawater intrusion into aquifers in coastal areas.

[Brief description of drawings]

FIG. 1 is a flowchart of the method of the present invention.

[Fig. 2] Correlation diagram between water injection volume or pumped water volume and well water level

[Fig. 3] Schematic diagram of work process

[Explanation of symbols]

 1 Water Collection Channel 2 Screen 3 Filtration Device 4 First Tank 5 Water Quality Measuring Device 7 Vacuum Degassing Device 10 Removal Device 11 Second Tank 15 Drainage Channel 17 Well 18 Water Level Meter 20 Water Injection Pipe 21 Pumping Pipe

Claims (1)

[Claims] 1. Collecting precipitation in a target area into a water collection channel,
Surface water that can be obtained in the area will also be led to the water collection channel. At the end of the water collection channel, these substances floating in water are removed by a screen, soil particles and the like mixed in next are removed by a filtration device, and the passed water is stored in the first tank. Concentration of some of the water in the first tank is measured for predicted pollutants, and if the concentration of any of the substances exceeds the set concentration specified for each water quality, the water in the first tank has it. The water quality is treated with a removing device, and the water which is confirmed to be below the set concentration is transferred to the second tank. The water in the first tank below the set concentration or the water in the second tank below the set concentration goes through the vacuum deaerator as quickly as possible, and has a pipe with an outlet at a position lower than the lower limit water level set for each well. Through the water injection well defined by the following method. Each well will be a well equipped with a water gauge for pumping and water injection, and the upper and lower water levels will be set for each well. The order of water injection wells is determined based on the large amount of water that can be injected until the well water level at the time of injection into each well reaches the upper limit water level. When the water level of the water injection well reaches the upper limit water level, water injection is stopped and water injection is moved to the next well. The order of pumping is determined based on the large amount of pumpable water until the well level at the time of pumping reaches the lower limit. When the well water level reaches the minimum water level during pumping, pumping will be stopped and pumped to the next well. A method of pumping pressurized groundwater from a group of wells with water injection consisting of the above methods.