CN110905403B - Construction method of large-diameter groundwater environment monitoring well - Google Patents

Construction method of large-diameter groundwater environment monitoring well Download PDF

Info

Publication number
CN110905403B
CN110905403B CN201911248804.2A CN201911248804A CN110905403B CN 110905403 B CN110905403 B CN 110905403B CN 201911248804 A CN201911248804 A CN 201911248804A CN 110905403 B CN110905403 B CN 110905403B
Authority
CN
China
Prior art keywords
well
pipe
construction
drilling
water
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201911248804.2A
Other languages
Chinese (zh)
Other versions
CN110905403A (en
Inventor
刘术湘
岳进松
李东升
曹小宇
谢震
王虎
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Wuhan Surveying Geotechnical Research Institute Co Ltd of MCC
Original Assignee
Wuhan Surveying Geotechnical Research Institute Co Ltd of MCC
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Wuhan Surveying Geotechnical Research Institute Co Ltd of MCC filed Critical Wuhan Surveying Geotechnical Research Institute Co Ltd of MCC
Priority to CN201911248804.2A priority Critical patent/CN110905403B/en
Publication of CN110905403A publication Critical patent/CN110905403A/en
Application granted granted Critical
Publication of CN110905403B publication Critical patent/CN110905403B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • EFIXED CONSTRUCTIONS
    • E21EARTH DRILLING; MINING
    • E21BEARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B7/00Special methods or apparatus for drilling
    • EFIXED CONSTRUCTIONS
    • E21EARTH DRILLING; MINING
    • E21BEARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B17/00Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Cables; Casings; Tubings
    • EFIXED CONSTRUCTIONS
    • E21EARTH DRILLING; MINING
    • E21BEARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B25/00Apparatus for obtaining or removing undisturbed cores, e.g. core barrels, core extractors
    • EFIXED CONSTRUCTIONS
    • E21EARTH DRILLING; MINING
    • E21BEARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B43/00Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
    • E21B43/02Subsoil filtering
    • E21B43/04Gravelling of wells
    • EFIXED CONSTRUCTIONS
    • E21EARTH DRILLING; MINING
    • E21BEARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B43/00Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
    • E21B43/02Subsoil filtering
    • E21B43/10Setting of casings, screens, liners or the like in wells
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N1/00Sampling; Preparing specimens for investigation
    • G01N1/02Devices for withdrawing samples
    • G01N1/04Devices for withdrawing samples in the solid state, e.g. by cutting

Abstract

The invention provides a construction method of a large-caliber groundwater environment monitoring well. The construction method specifically comprises the steps of monitoring well drilling coring and multistage reaming construction, core taking and arranging, well pipe installation, well washing, water pumping test and well mouth protection device installation. The invention can finish the construction process by adopting a conventional engineering investigation drilling machine and a common core drilling machine, has simple construction, greatly saves the cost, can obtain good environmental and economic benefits, can easily generate stronger hydraulic connection between the well wall of the large-caliber monitoring well and the peripheral underground aquifer, is filled with filter materials between the well walls, can carry out water pumping test and well washing work, strengthens the hydraulic connection between the underground water and the well, and can dynamically reflect the construction method integration of the real-time condition of the underground water environment.

Description

Construction method of large-diameter groundwater environment monitoring well
Technical Field
The invention relates to the field of environment-friendly monitoring of underground water environment monitoring station construction, in particular to a construction method of a large-caliber underground water environment monitoring well.
Background
With the development of socioeconomic in China, the environmental problem of underground water is increasingly outstanding, and the underground water in partial areas is seriously polluted. Scientific and accurate investigation, evaluation and treatment of contaminated groundwater is becoming increasingly important. The main means of the current groundwater pollution investigation and water quality monitoring is to take a sample to test in a groundwater monitoring well, so the groundwater environment monitoring well is a water quality monitoring well which is set up for accurately grasping the groundwater environment quality condition and the dynamic distribution change condition of pollutants in underground water, and the groundwater environment monitoring well usually comprises a wellhead protection device, a well wall pipe, a sealing and water stopping layer, a water filter pipe, a surrounding filling filter material, a sedimentation pipe, a well bottom and other components. The method has the advantages that a scientific, reasonable and complete-function underground water monitoring well pattern is established, and accurate and comprehensive basic data can be provided for scientific management, reasonable utilization and timely protection of underground water resources.
At present, most underground water environment monitoring wells are formed by adopting a hydraulic punching method, the construction process is simple, the cost is low, but the aperture of the constructed monitoring well is only 50-108mm, and the aperture is smaller. The monitoring work of the groundwater environment monitoring well is a long-term process, the caliber of the groundwater environment monitoring well is small, frequent maintenance is needed, if the groundwater environment monitoring well is not maintained for a long time, the groundwater environment monitoring well is easy to block, fill and deposit, more automatic monitoring instruments cannot be put into the groundwater environment monitoring well, the groundwater environment monitoring well cannot be used quickly, and when a water sample is taken again, a deep well pump cannot be used for pumping water and washing the well, so that the deviation of a water quality analysis result is large. And the underground water environment monitoring well construction is different from the common water well construction and the engineering exploration drilling construction, not only the geological characteristics and the hydrogeological characteristics of a rock-soil layer need to be checked clearly, but also the characteristics of a water well need to be considered, and the underground water of the small-caliber monitoring hole is in a non-flowing state and cannot truly reflect the quality of the underground water. However, if a large-diameter monitoring well needs to be constructed by the conventional construction method, a large-size well drilling machine is generally needed, the tonnage of the well drilling machine is large, the installation is time-consuming and labor-consuming, electricity is generally used as a power source, a 380V power supply needs to be connected from a factory or an electric power department, the construction period is long, and the construction cost is high. The monitoring well is different from an industrial or civil water well, the water yield requirement is not met, and the waste is serious due to the adoption of large-scale water well mechanical construction.
In the process of monitoring the underground water environment, related monitoring equipment is generally required to be arranged at a wellhead, related sensors are arranged underground, and monitored related data are transmitted out in a manual or wireless communication mode. Most of the well mouths of the existing groundwater environment monitoring wells are not provided with protective equipment, and the well environment is easily interfered by external factors or considered factors, so that the monitoring accuracy of the groundwater parameters in the area is influenced. And some underground water monitoring equipment is directly placed in the field, and the problem of loss or damage can also occur without protective measures
In addition, in the process of monitoring the water environment, the underground hydrogeological conditions of the region need to be known, so that before normal monitoring, coring needs to be performed on the region to survey the hydrogeological conditions of the region, and reference data is provided for later-stage calculation monitoring.
Disclosure of Invention
The invention provides a construction method of a large-caliber groundwater environment monitoring well aiming at the problems in the background art, the construction method can greatly improve the caliber of the monitoring well, can obtain good environmental and economic benefits, and saves the cost.
In order to solve the technical problem, the invention provides a construction method of a large-caliber groundwater environment monitoring well, which is characterized by comprising the following specific steps of:
(1) drilling construction of the monitoring well: directly adopting a drilling machine to carry out coring and drilling at a set position to a designed depth, and then adopting reamer bits with different diameters to expand the aperture of the drilled hole to the designed aperture of the monitoring well in a plurality of times; aiming at the fourth series aquifer, the drilling machine adopts an engineering exploration drilling machine, and a drilling hole penetrates through the fourth series loose covering layer deeply and enters a position of more than 5 meters of bedrock; aiming at a bedrock fracture water layer or a bedrock confined water layer, drilling by using a core drilling machine until the drilling depth reaches the bedrock water layer or enters below an erosion datum plane; in the drilling process, when the drilling depth is less than 100m, the hole inclination is not more than 1 degree; when the drilling depth is more than or equal to 100m, the hole inclination is not more than 2 degrees;
(2) core collection and arrangement: after the core is taken out, hydrogeology is compiled; in the coring process, super-return drilling is not allowed, the cohesive soil sampling rate is more than 85 percent, sandy soil is more than 70 percent, gravel (pebble) stone is more than 40 percent, bedrock is more than 85 percent, and the total pore is more than 70 percent on average;
(3) mounting a well pipe: the well pipe is made of stainless steel pipe and is higher than the ground of the monitoring well; the well pipe sequentially comprises a wellhead pipe, a filter pipe and a settling pipe from top to bottom, the settling pipe is installed at the bottom of the monitoring well, the length of the settling pipe is not less than 3m, and the bottom of the settling pipe is welded and sealed by a steel plate; and gravel is filled between the pipe wall and the hole wall in time after the well pipe is installed;
(4) hole washing: before hole washing, water stopping is well carried out on top and bottom plates of each aquifer, and after the filter pipe is arranged, the hole is washed immediately;
(5) water pumping test: performing a maximum falling stroke steady flow water pumping test, wherein the water pumping stabilization time is at least eight hours, recovering the water level observation after the water pumping test is finished, and taking a group of water samples before and after the test;
(6) construction well head protection device: the wellhead protection device comprises a reinforced concrete base constructed around the part of the well pipe exposed out of the ground and an orifice cap arranged at the top of the concrete base, wherein the base is partially embedded into the ground, the height of the part of the base exposed out of the ground is 8-15 cm smaller than that of the part of the well pipe exposed out of the ground, the orifice cap is 15-20 cm higher than the orifice of the well pipe, and a locking device is arranged on the orifice cap.
The further technical scheme of the invention is as follows: aiming at the fourth series aquifer in the step (1), the drilling depth is generally 20m, firstly, drilling is carried out to the position below an artificial filling or plant layer, an orifice pipe is arranged, then, construction is carried out in a single pipe, low solid-phase mud or clean water is adopted for drilling, coring and drilling are carried out to a basal rock surface, then, single pipe reaming is carried out, low solid-phase mud or clean water is adopted for drilling until the aperture reaches the design requirement, and the logging work is completed; aiming at a bedrock fracture water layer or a bedrock confined water layer, the drilling depth is generally 100m, firstly, coring and drilling are carried out to a stable bedrock surface, then reaming is carried out to meet the design requirement of the aperture, a water stop pipe is put in, a rope coring drilling process is continuously adopted, low solid-phase mud or clean water is adopted to drill to the design depth, primary logging work is carried out, then, a reaming bit is adopted to ream to the design aperture, and secondary logging work is carried out.
The further technical scheme of the invention is as follows: the well diameter of the monitoring well structure reaches 168mm, and the monitoring well structure is connected by 304 type stainless steel threads.
The further technical scheme of the invention is as follows: the rock core taken out in the step (2) is timely cleaned, boxed, numbered, described and photographed, and the arrangement of the rock core cannot be reversed, disordered or lost; wherein, the rock cores which belong to block, granular and powder are folded according to the size of the diameter 2/3 of the drill bit, and the granular and clastic rock cores are properly kept near the drill hole by selecting proper positions to prevent mixing and rain erosion loss.
The invention has the following excellent technical scheme: the water stop pipe, the filter pipe and the sedimentation pipe in the step (3) are all stainless steel pipes with the thickness of 5mm, and the well pipe is 0.5-0.8 m higher than the ground of the monitoring well; when gravel is filled, filling a filter material mainly comprising siliceous sand and gravel from a position which is not less than 1m below the bottom end of the filter pipe to a position which is not less than 3m above the top end of the filter pipe, and filling an annular gap from the top end of the filter material to a well section of a well mouth with a dry clay ball with the particle size of 5-15mm for sealing and water stopping; and filling gravel at the bottom of the bedrock section aiming at the bedrock section with the bedrock burial depth smaller than the designed monitoring well hole depth.
The invention has the following excellent technical scheme: the filter pipe in the step (3) adopts a filter pipe with the porosity of 25-30%, and the diameter of the opening of the filter pipe is 18-22 mm; the lower part can be open-hole to form a well when the bedrock is relatively complete or does not drop.
The invention has the following excellent technical scheme: in the step (4), clay balls with the diameter not more than 40mm are adopted to tamp water; the hole washing is specifically that a drilling machine is adopted to change slurry with a water pump, then a submersible pump is adopted to pre-pump water and wash a well, and after gravel is thrown on a well pipe, the hole washing is repeatedly carried out in a steel brush or piston or air compressor well washing mode until the water is sand-cleaned and the water level reaction is sensitive; and (4) trial pumping is carried out for 2-3 h in the hole washing process to determine the maximum water level depth reduction.
The invention has the following excellent technical scheme: accurately measuring the coordinates of the hole position of the drilling hole, the ground elevation of the hole position and the height of the pipe orifice higher than the ground before the water pumping test in the step (5), and checking the water pumping equipment, the control equipment and the drainage system; the maximum drawdown value of the monitoring well of the diving aquifer is 5 meters, and the maximum drawdown value of the bedrock is 25 meters.
The invention has the following excellent technical scheme: and the logging work adopts electrical logging or hydrological logging, the position of the filter is determined according to the logging result, the logging result in the hole is subjected to detailed layering, a single layer larger than 10cm cannot be leaked out in the fourth series of holes, and the main geological characteristics of each stratum are analyzed and named.
The further technical scheme of the invention is as follows: the core description is used for mainly describing the structure and the granularity composition of soil grains aiming at a fourth system aquifer; bedrock requirements describe the composition, structure and architecture of the rock, integrity to joints, fractures and cores, and RQD values.
In order to solve the problem of construction of the large-caliber underground water environment monitoring well, the invention firstly adopts a core drilling process to carry out core drilling and then adopts a hole expanding drilling process, so that the caliber of the monitoring well can be greatly improved. The core taking process of the fourth series aquifer adopts a double-pipe drilling tool or a special soil sampler for core taking, and the core taking is required to have no disturbance, large diameter and continuous full core taking as much as possible; the bedrock section adopts a rope core drilling process, measures such as hard drilling, small water quantity, slow rotating speed and the like are adopted for a broken layer, so that the core taking rate reaches over 90 percent, and the technical requirement of completely identifying the hydrogeological characteristics of the stratum is met. The fourth series aquifer reaming and drilling process adopts a composite drill bit and single-pipe drilling process, and requires to perform reaming in stages and perform reaming for multiple times; the bedrock aquifer also adopts the compound sheet drill bit to carry out multi-stage reaming, and the difference is that the bedrock aquifer reaming drill bit is provided with a guide rod. And the diameter of the multi-stage drilling is not allowed to span by single reaming, and finally, the construction of a water filter pipe, a well washing, a water pumping test and a monitoring well mouth protection device is sequentially carried out, so that the final hole diameter of the monitoring well reaches 168mm, and the diameter of the monitoring well can be greatly improved.
The invention has the beneficial effects that:
(1) the method has the advantages that the core drilling of geology and exploration is considered, underground hydrogeological conditions are compiled, described and summarized, and data are provided for calculating hydrogeological parameters of the monitoring well in the next step;
(2) the invention adopts a reaming drilling process, enlarges the small-caliber drill hole to reach the aperture of the monitoring well, ensures that the small-caliber drill hole has strong hydraulic connection with the surrounding stratum, ensures the smoothness of the hole wall, and is beneficial to running water stop pipes, filter pipes and well pipes; the hole expansion is carried out by stages and steps, the requirement on equipment is reduced, and the construction method of the large-caliber monitoring well is low in cost;
(3) the method can be suitable for two conditions of a fourth system aquifer and a bedrock aquifer, including most of geological conditions encountered at present;
(4) according to the invention, the protection device is arranged on the wellhead of the monitoring well, so that the monitoring well and wellhead equipment can be protected, the monitoring accuracy of underground water parameters in the area is prevented from being influenced by the interference of external factors on the environment in the well, and the monitoring equipment can be prevented from being stolen or damaged;
(5) the water pumping test of the invention is only one maximum falling stroke, thus avoiding the problems of time and labor waste and poor economy caused by three falling strokes and even the water pumping test with observation holes according to the hydrological specification requirements.
The invention can finish the construction process by adopting a conventional engineering investigation drilling machine and a common core drilling machine, has simple construction, greatly saves the cost, can obtain good environmental and economic benefits, can easily generate stronger hydraulic connection between the well wall of the large-caliber monitoring well and the peripheral underground aquifer, is filled with filter materials between the well walls, can carry out water pumping test and well washing work, strengthens the hydraulic connection between the underground water and the well, and can dynamically reflect the construction method integration of the real-time condition of the underground water environment.
Drawings
FIG. 1 is a flow chart of a construction process according to the first embodiment;
FIG. 2 is a flow chart of a construction process according to the second embodiment;
fig. 3 is a schematic structural diagram of a wellhead protection device of the present invention.
In the figure: 1-base, 2-orifice cap, 3-locking device, 4-well pipe.
Detailed Description
The invention is further illustrated below with reference to examples and figures.
In the following examples, the well casing is preferably a stainless steel pipe with a thickness of 5mm, preferably a stainless steel seamless pipe of type 304, taking into account the corrosion resistance requirements, and should be 0.6m above the ground in the vicinity of the monitoring well. The well head protection device constructed on the well mouth, as shown in figure 3, adopts a concrete type, plays a role of protecting monitoring instruments and equipment and a well head, and specifically comprises a base 1 made of reinforced concrete and an orifice cap 2 made of a thick steel plate, wherein the height of the base 1 is 80cm, the base is constructed outside a well pipe 4, the height of a ground entering part is 30cm, the height of the exposed ground is 50cm, and the height is 10cm lower than that of the well mouth; the diameter of the base 1 is larger than that of the orifice cap 2, and can be generally 50 cm; the thickness of the orifice cap steel pipe is 10mm, the height is 30cm, and the diameter is 34 cm; the orifice cap is provided with a special locking device 3 which is matched with a special unlocking tool.
The first embodiment is as follows: for the item of monitoring the water-containing groundwater in the Dexing city of Jiangxi province, the topography of hills and hills mainly has the stratum condition of the fourth series of diving aquifers, and the bedrock surface is buried shallowly. The drilling depth is determined according to the drilling purpose so as to achieve the purposes of controlling the hydrogeological unit area and dynamically monitoring the hydrogeological unit area, and for a fourth series aquifer, the drilling hole depth penetrates through a fourth series loose covering layer and enters a bedrock by more than 5 meters, and the drilling hole depth is generally 20 meters. The inventor of the application adopts the method of the invention to construct a large-caliber underground water environment monitoring well aiming at the project, a common engineering exploration drilling machine such as an XY-1 type or XY-150 type high-speed hectometer drilling machine is used in the construction project, the drilling depth of the project is less than 100m, the hole inclination is not more than 1 degree, the specific construction process is as shown in figure 1, and the specific steps are as follows:
(1) adopting coring and reaming processes to carry out the drilling construction of the monitoring well: selecting the diameter of 0-1.0 mSingle pipe construction, solid mud is used to drill into the artificial filling soil or plant layer and the diameter is setAn orifice tube; then 1m to the fourth series of cover layers, with diameters selectedSingle tube fertilizer applicatorDrilling with low solid-phase mud or clean water to the surface of the bed rock, and selecting the diameter of the covering layer from 1m to the fourth seriesAnd diameterThe two-stage single-tube reaming is carried out by adopting low solid-phase slurry or clear water drilling, core drilling and reaming construction are completed, hydrological logging is carried out, the position of a filter is determined according to a logging result, the logging result in the hole needs to be layered in detail, a single layer larger than 10cm cannot be leaked out from a fourth series of holes, and the main geological characteristics of each stratum are analyzed and named after being matched with geological technicians;
(2) core collection and arrangement: after the core is taken out, hydrogeology is compiled; the structure and the granularity composition of soil grains are mainly described in the core description;
(3) mounting a well pipe: 3m of a settling pipe, 6m of a filter pipe and a wellhead pipe (the hole depth is minus 9m) are put into the system, the complete acceptance of the designed hole depth is achieved, and the next step is not executed;
(4) hole washing: before hole washing, water stopping is well carried out on top and bottom plates of each aquifer, and after the filter pipe is arranged, the hole is washed immediately;
(5) water pumping test: performing a maximum falling stroke steady flow water pumping test, wherein the water pumping stabilization time is at least eight hours, recovering the water level observation after the water pumping test is finished, and taking a group of water samples before and after the test;
(6) a wellhead protection device is constructed.
In the well hole construction process, when the section with small burial depth of the base rock surface is used, the diameter is set in the well pipeSingle pipe construction, low solid phase mud or clean water drilling, core drilling to designed hole depth and continuous lowering diameterSingle tube reaming, continued run-in diameter And (3) reaming by using a single pipe, so that the inner diameter of the underground water monitoring well reaches 150mm, is basically consistent with the inner diameter of the well pipe at the upper part, and does not influence the installation of a monitoring instrument.
Example two: aiming at underground water monitoring projects of a Fujia dock stope of Jiangxi Dexing copper mine, the underground water monitoring projects are positioned on stope slopes, and complete phyllite and granite spangle rock strata are mainly arranged except a small amount of blasting loose rock layers on the slopes. Aiming at a bedrock monitoring well, regional geological data and hydraulic ring data are firstly analyzed, a region with large fracture development or bedrock fracture water runoff modulus is selected for implementation, the drilling hole depth generally enters a bedrock aquifer or enters a certain depth below an erosion datum plane, and generally 100 meters can be selected. The inventor of the application adopts the method of the invention to construct a large-caliber underground water environment monitoring well aiming at the project, a general geological exploration drilling machine, such as XY-4 type, XY-42 type and XY-44T vertical shaft type drilling machines and other full hydraulic deep hole drilling machines are used in the construction project, the drilling depth of the project reaches 100m, the hole inclination is not more than 2 degrees, the specific construction process is shown in figure 2, and the specific steps are as follows:
(1) adopting coring and reaming processes to carry out the drilling construction of the monitoring well: the diameter is selected firstSingle-pipe construction coring drilling to stable base rock surface (even 0-10.0 m), using solid-phase mud, then using diameter at 0-10.0 mAnd diameterTwo-stage single-tube reaming with solid-phase slurry and feeding diameterAn orifice tube;
at 10.0-100.0 m, the first choice isDrilling by (HQ) rope core drilling process, adopting low solid-phase mud or clean water to drill, hydrographic logging after drilling, and selecting diameter Drilling with (PQ) reamer bit by once reaming, low solid mud or clean water, and selecting diameterSecondary expanding bit for expanding hole and drilling, low solid mud or clean water for drilling, and final diameterDrilling by using a reamer bit for three times of reaming, and drilling by using low solid-phase mud or clean water;
(2) core collection and arrangement: after the core is taken out, hydrogeology is compiled; wherein, the bedrock requirement describes the composition, structure and structure of the rock, and the joint, the crack and the integrity of the rock core and the RQD value are described in an important way, and the record needs to be detailed and accurate.
(3) Mounting a well pipe: running in3m of a settling pipe, 30m of a bedrock framework filter pipe and 67m of a wellhead pipe;
(4) hole washing: before hole washing, water stopping is well carried out on top and bottom plates of each aquifer, and after the filter pipe is arranged, the hole is washed immediately;
(5) water pumping test: performing a maximum falling stroke steady flow water pumping test, wherein the water pumping stabilization time is at least eight hours, recovering the water level observation after the water pumping test is finished, and taking a group of water samples before and after the test;
(6) a wellhead protection device is constructed.
In the hole expanding processes of the first and second implementation, the hole expanding speed is not too high and is adaptive to the stratum; reaming should be continuously carried out, and stopping drilling in midway should extract the drilling tool out of the hole; the reaming drill has enough strength and is additionally connected with a guide device; the hole expanding drilling tool is provided with a centralizer, and the drilling hole is kept straight and small holes at the lower part are unobstructed during hole expanding; the drill is lifted once every small shift, and problems are found and timely treated.
In the first embodiment and the second embodiment, in the drilling process, the layers for dividing the lithology of the stratum, the fracture zone, the horizon of the aquifer, the burial depth, the thickness and the like of the stratigraphic layers are observed, described and recorded in detail; the method comprises the steps of collecting various samples strictly according to the design requirements of drilling holes, bagging and sealing the collected various samples immediately according to related requirements, indicating the level and the depth of sampling, filling various labels and sample delivery lists, delivering the samples as soon as possible, and storing the data in a warehouse in time. When the drilling machine encounters the phenomena of water leakage, water burst, drill clamping, drill dropping and the like in the drilling process, the hole depth of the drilling machine is recorded in detail, and the initial drill dropping depth and the drill clamping position which encounter the drill dropping phenomenon are recorded in detail. The super-drill-in is not allowed in the processes of core sampling rate and arrangement, the clay sampling rate is more than 85 percent, the sandy soil is more than 70 percent, the gravel (pebble) is more than 40 percent, the bedrock is more than 85 percent, and the average total pore is more than 70 percent; after the core is taken out, timely cleaning, arranging the core, correcting the length, the depth and the core sampling rate of the core, boxing, numbering, filling a core card and taking a picture; when the core is boxed, the core is loaded into the core box according to the upper and lower sequence, the core cannot be placed disorderly or inverted, the core arrangement cannot be reversed, disordered and lost, and the core is numbered in time, the handwriting of the core plate needs to be neatly and clearly, the data is accurate, a recorder checks whether the core plate is matched with the class report record at any time, the problem is found and corrected in time, and the naming and the description of the core are carried out according to the standard requirement; the blocky, granular and powdery rock cores are folded according to the size of the diameter 2/3 of the drill bit; both granular and clastic cores are required to be properly kept in proper positions near the drilled hole to prevent mixing and rainwater erosion loss.
The logging in the first embodiment and the second embodiment requires simple hydrogeological observation requirements, the initial water level is noticed, the water level observation in the hole is carried out after the drill is lifted and before the drill is lowered each time, the detailed records are required to be carried out when water burst and water leakage are found in the drilling process, the drilling is stopped when the flow is extremely large, the flow is observed and recorded in detail, and the stable water level is observed after the final hole. The color change characteristics of the slurry, the specific position of slurry leakage or slurry turnover, the hole depth and the like of the drilled hole are noticed and recorded in detail.
In the first embodiment and the second embodiment, gravel filling is performed in time after the well pipe is installed, and filter materials mainly comprising siliceous sand and gravel with different particle sizes and better grading roundness are selected for filling according to the position of the underground water monitoring well and the water-bearing stratum condition. The filling filter material is filled from the position which is not less than 1m below the bottom end of the filter pipe to the position which is not less than 3m above the top end of the filter pipe. The annular gap from the top end of the filling filter material to the well head well section is sealed and sealed, and dry clay balls with the particle size of 5-15mm are preferably selected as the material for sealing and sealing.
Before the hole is washed in the first embodiment and the second embodiment, the water is stopped at the top and bottom plates of each aquifer by the water pumping hole, and the water is tamped by clay balls, wherein the diameter of the clay balls is not more than 40mm, and preferably, the clay balls with the particle size of 5-15mm are selected; after the filter pipe is arranged below the water pumping test hole, the hole is washed immediately, the hole washing method requires that the lower pipe is punched by clean water after gravel is thrown, and the hole washing is repeatedly carried out by a piston and an air compressor until the water is cleaned and sand is clean and the water level reaction is sensitive.
In the water pumping tests in the first embodiment and the second embodiment, according to relevant regulations of water supply hydrogeological survey standards (GB50027), the water pumping test requires that stable flow water pumping is mainly carried out, the water pumping is stable for 8 hours, and the water level recovery observation is carried out according to the unstable flow requirement after the water pumping is finished. Before the water pumping test, besides experimental water pumping, the hole position coordinates of the drill holes, the ground elevation at the hole positions and the height of the pipe orifices higher than the ground are accurately measured. And (4) checking whether the pumping equipment can normally operate or not, whether the control equipment for controlling the flow is reliable or not, and checking whether the drainage system has a leakage phenomenon or not and is smooth. Check if the groundwater level is stable and take care of possible effects of the surrounding environment on the observations. The maximum depth reduction value is determined according to the capacity of the pumping equipment. The maximum drawdown value of the submerged aquifer monitoring well is 5 meters, and the maximum drawdown value of the bedrock is 25 meters. In the stable duration, the relation curve of the water inflow and the dynamic water level and the time fluctuates in a certain range, and the water inflow and the dynamic water level have no continuous rising or falling tendency. When the water level is reduced to less than 10m and the water is pumped by a submersible pump, a centrifugal pump and the like, the fluctuation value of the water level is not more than 5 cm. Generally, the average water level drop value is not more than 1%, and the water inflow fluctuation value cannot exceed 3% of the average flow. And immediately observing the recovered water level after the pump is stopped, wherein the observation time interval is basically the same as the requirement of the pumping test. If the water level is not changed for 3 hours continuously or the water level is changed in a single direction, the change of the water level per hour in 4 hours continuously does not exceed 1cm, or the rising and falling of the water level are consistent with the change of the natural water level, the observation can be stopped
The construction method of the invention is characterized in that the open pore caliber of the loose rock pore water monitoring wellHole opening caliber of bedrock fracture water monitoring wellThe well pipe diameter is not less than 168 mm. Because the well casing diameter is bigger, when the siltation is blockked up in the well, can adopt the deep-well pump to draw water and wash the well, consequently, the monitoring well can be used for a long time forever.
Implement one and the second embodiment and after the monitoring well construction is accomplished, need set up at the well head and mark the tablet, its signboard main action is: and underground water monitoring sites are marked to play a role in protection and propaganda. The nameplates should be uniform and the materials should be protected from wind, rain and rain. The signboard is a signboard with the specification of 500mm in length, 300mm in width and 2mm in thickness, and the font of the ' xxx x project underground water monitoring site ' is the height of the clerical letter of 6cm (No. 200), and the font of the ' title, warning language, monitoring site number, monitoring project, setting date, belonging unit, contact call ' and the font of the ' clerical letter of 4.5cm (No. 150). The monitoring well after the construction can be used for monitoring, and the monitoring well has water sample detection indexes (22 items) of pH value, total hardness, total dissolved solids, sulfate, chloride, permanganate index, nitrate, nitrite, ammonia nitrogen, fluoride, iron, copper, zinc, molybdenum, mercury, arsenic, cadmium, hexavalent chromium, lead, nickel, total coliform group bacteria and total bacteria number.
The two examples above are detailed for two different water layers, and the description is more specific and detailed, but should not be construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims (7)

1. A construction method of a large-caliber groundwater environment monitoring well is characterized in that the construction method is used for constructing the monitoring well with the well diameter reaching 168mm, a well pipe is connected by adopting 304 type stainless steel threads, and the method comprises the following specific steps:
(1) drilling construction of the monitoring well: directly adopting a drilling machine to carry out coring and drilling at a set position to a designed depth, and then selecting reamer bits with different diameters to expand the aperture of the drilled hole to the designed aperture of the monitoring well in a plurality of times; aiming at the fourth series aquifer, the drilling machine adopts an engineering exploration drilling machine, the drilling depth is 20m, firstly, the drilling is carried out to the position below an artificial filling or plant layer, a wellhead pipe is put into the drilling position, then, the construction is carried out on a single pipe, low solid-phase mud or clean water is adopted for drilling, the core is drilled to a bedrock surface, then, the drilling is carried out through multiple chambering until the aperture reaches the design requirement, and the logging work is completed; aiming at a bedrock fracture water layer or a bedrock confined water layer, drilling a hole by using a core drilling machine, wherein the drilling depth is 100m, firstly, coring and drilling to a stable bedrock surface, then reaming to meet the design requirement of the aperture, putting into a wellhead pipe, continuously adopting a rope coring drilling process, drilling to the design depth by using low solid-phase mud or clear water, carrying out one-time logging work, and then reaming to reach the design aperture by using a reaming bit through multiple reaming; in the drilling process, when the drilling depth is less than 100m, the hole inclination is not more than 1 degree; when the drilling depth is more than or equal to 100m, the hole inclination is not more than 2 degrees;
(2) core collection and arrangement: after the core is taken out, hydrogeology is compiled; in the coring process, super-return drilling is not allowed, the cohesive soil sampling rate is more than 85 percent, sandy soil is more than 70 percent, gravel or pebble is more than 40 percent, bedrock is more than 85 percent, and the total hole average is more than 70 percent; the taken out rock cores are cleaned, boxed, numbered, described and photographed in time, and the arrangement of the rock cores cannot be reversed, disordered and lost; wherein, the rock cores which belong to block, granular and powder are folded according to the size of the diameter 2/3 of the drill bit, and the granular and clastic rock cores are properly kept at the proper positions near the drill hole to prevent mixing and rain erosion loss;
(3) mounting a well pipe: the well pipe is made of stainless steel pipes, and the height of the well pipe is 0.5-0.8 m higher than the ground of the monitoring well; the well pipe sequentially comprises a wellhead pipe, a filter pipe and a settling pipe from top to bottom, the settling pipe is installed at the bottom of the monitoring well, the length of the settling pipe is not less than 3m, and the bottom of the settling pipe is welded and sealed by a steel plate; and gravel is filled between the pipe wall and the hole wall in time after the well pipe is installed;
(4) hole washing: before hole washing, water stopping is well carried out on top and bottom plates of each aquifer, and after the filter pipe is arranged, the hole is washed immediately;
(5) water pumping test: performing a maximum falling stroke steady flow water pumping test, wherein the water pumping stabilization time is at least eight hours, recovering the water level observation after the water pumping test is finished, and taking a group of water samples before and after the test;
(6) construction well head protection device: the wellhead protection device comprises a reinforced concrete base constructed around the part of the well pipe exposed out of the ground and an orifice cap arranged at the top of the concrete base, wherein the base is partially embedded into the ground, the height of the part of the base exposed out of the ground is 8-15 cm smaller than that of the part of the well pipe exposed out of the ground, the orifice cap is 15-20 cm higher than the orifice of the well pipe, and a locking device is arranged on the orifice cap.
2. The construction method of the large-caliber groundwater environment monitoring well as claimed in claim 1, wherein the construction method comprises the following steps: the water stop pipe, the filter pipe and the sedimentation pipe in the step (3) are all stainless steel pipes with the thickness of 5 mm; when gravel is filled, filling a filter material mainly comprising siliceous sand and gravel from a position which is not less than 1m below the bottom end of the filter pipe to a position which is not less than 3m above the top end of the filter pipe, and filling an annular gap from the top end of the filter material to a well section of a well mouth with a dry clay ball with the particle size of 5-15mm for sealing and water stopping; and filling gravel at the bottom of the bedrock section aiming at the bedrock section with the bedrock burial depth smaller than the designed monitoring well hole depth.
3. The construction method of the large-caliber groundwater environment monitoring well as claimed in claim 1, wherein the construction method comprises the following steps: the filter pipe in the step (3) adopts a filter pipe with the porosity of 25-30%, and the diameter of the opening of the filter pipe is 18-22 mm; the lower part can be open-hole to form a well when the bedrock is relatively complete or does not drop.
4. The construction method of the large-caliber groundwater environment monitoring well as claimed in claim 1, wherein the construction method comprises the following steps: in the step (4), clay balls with the diameter not more than 40mm are adopted to tamp water; the hole washing is specifically that a drilling machine is adopted to change slurry with a water pump, then a submersible pump is adopted to pre-pump water and wash a well, and after gravel is thrown on a well pipe, the hole washing is repeatedly carried out in a steel brush or piston or air compressor well washing mode until the water is sand-cleaned and the water level reaction is sensitive; and (4) trial pumping is carried out for 2-3 h in the hole washing process to determine the maximum water level depth reduction.
5. The construction method of the large-caliber groundwater environment monitoring well as claimed in claim 1, wherein the construction method comprises the following steps: accurately measuring the coordinates of the hole position of the drilling hole, the ground elevation of the hole position and the height of the pipe orifice higher than the ground before the water pumping test in the step (5), and checking the water pumping equipment, the control equipment and the drainage system; the maximum drawdown value of the monitoring well of the diving aquifer is 5 meters, and the maximum drawdown value of the bedrock is 25 meters.
6. The construction method of the large-caliber groundwater environment monitoring well as claimed in claim 2, wherein the construction method comprises the following steps: and the logging work adopts electrical logging or hydrological logging, the position of the filter is determined according to the logging result, the logging result in the hole is subjected to detailed layering, a single layer larger than 10cm cannot be leaked out in the fourth series of holes, and the main geological characteristics of each stratum are analyzed and named.
7. The construction method of the large-caliber groundwater environment monitoring well as claimed in claim 1, wherein the construction method comprises the following steps: the core description is used for mainly describing the structure and the granularity composition of soil grains aiming at a fourth system aquifer; bedrock requirements describe the composition, structure and architecture of the rock, integrity to joints, fractures and cores, and RQD values.
CN201911248804.2A 2019-12-09 2019-12-09 Construction method of large-diameter groundwater environment monitoring well Active CN110905403B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201911248804.2A CN110905403B (en) 2019-12-09 2019-12-09 Construction method of large-diameter groundwater environment monitoring well

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201911248804.2A CN110905403B (en) 2019-12-09 2019-12-09 Construction method of large-diameter groundwater environment monitoring well

Publications (2)

Publication Number Publication Date
CN110905403A CN110905403A (en) 2020-03-24
CN110905403B true CN110905403B (en) 2021-07-09

Family

ID=69823877

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201911248804.2A Active CN110905403B (en) 2019-12-09 2019-12-09 Construction method of large-diameter groundwater environment monitoring well

Country Status (1)

Country Link
CN (1) CN110905403B (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111946333B (en) * 2020-07-02 2021-05-18 临沂矿业集团菏泽煤电有限公司 Simple test and solution method for aquifer hydrogeological parameters under curtain grouting condition

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101070704A (en) * 2007-06-04 2007-11-14 上海地矿工程勘察有限公司 Controllable one-well lamina precipitation construction method
CN201883451U (en) * 2010-08-18 2011-06-29 天津市凿井总公司 Single-hole multi-layer underground water dynamic monitoring well
CN102137981A (en) * 2008-06-27 2011-07-27 瓦伊德·拉希德 Drilling tool and method for widening and simultaneously monitoring the diameter of wells and the properties of the fluid
US8664168B2 (en) * 2011-03-30 2014-03-04 Baker Hughes Incorporated Method of using composites in the treatment of wells
CN105954464A (en) * 2016-04-21 2016-09-21 北京中地泓科环境科技有限公司 Method for constructing soil gas and underground water monitoring wells
AU2015270330A1 (en) * 2014-06-04 2017-01-12 Engie Method and system for operating and monitoring a well for extracting or storing fluid
CN107366505A (en) * 2017-05-27 2017-11-21 中核通辽铀业有限责任公司 A kind of ground-dipping uranium extraction Novel drilling construction method
CN107816051B (en) * 2017-11-08 2019-10-11 中国五冶集团有限公司 Pressure-bearing property phreatic aquifer deep basal pit combination well dewatering construction method
CN110409405A (en) * 2019-07-05 2019-11-05 中国科学院南京土壤研究所 A kind of well building method of PRB groundwater monitoring well within the walls
CN110439029A (en) * 2019-08-14 2019-11-12 四川省地质矿产勘查开发局成都水文地质工程地质队 A kind of double-aquifer monitoring well device and its building method

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100909876B1 (en) * 2009-01-30 2009-07-30 주식회사 경동건설 Excavating apparatus of vertical hole and excavation method of vertical hole
JP2014202149A (en) * 2013-04-07 2014-10-27 廣明 松島 Geothermal power generation system
CN205036295U (en) * 2015-10-10 2016-02-17 中国石油集团川庆钻探工程有限公司 Full well section is from inhaling anti - recycle gas drilling system of formula
CN107460885A (en) * 2017-09-22 2017-12-12 中国路桥工程有限责任公司 A kind of relief well of deep foundation pit and its construction method
CN208330356U (en) * 2018-06-14 2019-01-04 贵州省地质矿产勘查开发局111地质大队 A kind of joint type water-level and water-temperature measuring device

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101070704A (en) * 2007-06-04 2007-11-14 上海地矿工程勘察有限公司 Controllable one-well lamina precipitation construction method
CN102137981A (en) * 2008-06-27 2011-07-27 瓦伊德·拉希德 Drilling tool and method for widening and simultaneously monitoring the diameter of wells and the properties of the fluid
CN201883451U (en) * 2010-08-18 2011-06-29 天津市凿井总公司 Single-hole multi-layer underground water dynamic monitoring well
US8664168B2 (en) * 2011-03-30 2014-03-04 Baker Hughes Incorporated Method of using composites in the treatment of wells
AU2015270330A1 (en) * 2014-06-04 2017-01-12 Engie Method and system for operating and monitoring a well for extracting or storing fluid
CN105954464A (en) * 2016-04-21 2016-09-21 北京中地泓科环境科技有限公司 Method for constructing soil gas and underground water monitoring wells
CN107366505A (en) * 2017-05-27 2017-11-21 中核通辽铀业有限责任公司 A kind of ground-dipping uranium extraction Novel drilling construction method
CN107816051B (en) * 2017-11-08 2019-10-11 中国五冶集团有限公司 Pressure-bearing property phreatic aquifer deep basal pit combination well dewatering construction method
CN110409405A (en) * 2019-07-05 2019-11-05 中国科学院南京土壤研究所 A kind of well building method of PRB groundwater monitoring well within the walls
CN110439029A (en) * 2019-08-14 2019-11-12 四川省地质矿产勘查开发局成都水文地质工程地质队 A kind of double-aquifer monitoring well device and its building method

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
"内蒙古中部大口径地下水监测并钻探技术";李春生;《科技资讯》;20160704;全文 *
"安徽淮南地区地下水监测井成井工艺分析";张金华;《资源信息与工程》;20181015;第33卷(第5期);第68-69页 *

Also Published As

Publication number Publication date
CN110905403A (en) 2020-03-24

Similar Documents

Publication Publication Date Title
CN104694746B (en) A kind of method of ion adsorption type re in_situ leaching and leaching ore deposit system thereof
CN102865103B (en) Distributed using method for mine underground water
RU2567564C1 (en) Method of distributed storage and use of ground waters in mine
CN201883451U (en) Single-hole multi-layer underground water dynamic monitoring well
CN104386409B (en) A kind of coal field surface drilling guides water source to store the water-retaining method in goaf
CN110905403B (en) Construction method of large-diameter groundwater environment monitoring well
CN109610525A (en) A kind of method of quick judgement water-stop curtain construction quality
CN102862775B (en) Distributed storage method of underground water of mine
CN101832137B (en) Pre-embedding method for coal seam roof strut
CN106285776A (en) A kind of unrestrained method of roof water based on Technology of Directional Drilling
CN108663724B (en) Coal mine underground reservoir position selection method based on water resource transfer path
Rodríguez-Estrella et al. Methodologies for abstraction from coastal aquifers for supplying desalination plants in the south-east of Spain
CN111191849B (en) Method for predicting water inflow of deep-buried working face in western mining area
CN204422007U (en) Multi-layer underground water level observation structure
CN110671053B (en) Well construction method for underground water layered sampling monitoring well
CN106761674A (en) It is a kind of integrate draw water and unrestrained water test the straight-through down-hole drilling device in ground
CN108343470B (en) A kind of nature moisturizing method of underground water seal cave depot water curtain system
Hölting et al. Groundwater Exploitation
CN108468528A (en) One kind the 4th is that deep-well is layered draw water antipriming and its water-stopping method that draws water
CN213209012U (en) Ground settlement monitoring layering mark and water level monitoring well
CN103334443A (en) Mud cement pebble layer composite geological impacting hole forming dewatering well construction method
Eastwood et al. Aquifer storage recovery—Wessex Water’s experience using the chalk aquifer
Bosch et al. Pumping seawater from coastal aquifers for supplying desalination plants
Zhenfang et al. Technology research of large underwater ultra-deep curtain grouting in Zhong-guan iron ore
CN213812473U (en) Device suitable for karst wetland earth's surface and ground water level monitoring

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant