Automated multi-parameter groundwater environmental stratified monitoring well applicable to contaminated sites

Abstract

The present invention discloses an automated multi-parameter groundwater environment stratified monitoring well applicable to polluted sites. Multiple aquifers in the drilling are sealed by packers, and an aquifer stratified sampling device is arranged in a single aquifer. The aquifer stratified sampling device includes a first diversion pipe, a first three-way joint, a first check valve, a second check valve, a first downhole air drive mechanism, a first pressure relief valve, a first threaded to NPT joint, a second threaded to NPT joint, a first downhole flow storage container, a third threaded to NPT joint, a third check valve, and a filtration and dialysis component. The present invention can achieve automated groundwater environment stratified monitoring, automated multi-parameter water quality detection, phased and hierarchical customized groundwater environment monitoring, with good water sample representativeness and further improved integration ability. It is applicable to groundwater pollution investigation and monitoring in the fields of site environmental monitoring and geological exploration, and can obtain the dynamic change law of groundwater chemical properties in the vertical three-dimensional space of the formation over time.

Description

Technical Field

[0001] The present invention belongs to the technical field of contaminated hydrogeology, and particularly relates to an automated multi-parameter groundwater environment layered monitoring well applicable to contaminated sites. Background Art

[0002] Groundwater is a fundamental and important resource for the natural ecosystem and human survival, and is an important factor related to the evolution of the Earth system and the survival of surface organisms.

[0003] Groundwater pollution control, ecological environment protection and restoration are inseparable from groundwater monitoring technology. Human activities have caused increasingly serious groundwater pollution, such as the infiltration of landfill leachate, the underground discharge or leakage of pollution sources in industrial parks, and the pollution of agricultural activities. These have caused pollution sources to infiltrate into shallow groundwater and spread horizontally and vertically to a larger affected area, from a point on the surface to a three-dimensional conical shape underground, from a line to a strip shape, resulting in varying degrees of groundwater quality pollution at different stratigraphic depths and distances from the ground pollution source. The successive promulgation of the "Soil Pollution Prevention and Control Action Plan" and the "Water Pollution Prevention and Control Action Plan" has shown the government's attention to the underground environment and the great improvement of the public's environmental protection awareness, which has led to an increasing demand for underground pollution monitoring and control technologies in regulatory departments and the industrial market. Among them, a large part of the underground environmental pollution problems come from surface leakage and infiltration and shallow surface engineering injection activities, especially threatening the underground aquifer closest to the surface. However, the current similar products on the market cannot meet the needs of this development direction and further development is required.

[0004] In recent years, the state has successively introduced a number of policies and technical specifications, suggesting that groundwater environment layered monitoring be carried out in combination with the technical development level. In 2015, the Ministry of Natural Resources issued the "1:50,000 Hydrogeological Survey Specification DZ / T 0282-2015", which pointed out that in areas with multi-layer aquifer distributions, it is advisable to monitor and control the main aquifers separately, and groundwater layered monitoring wells should be set up if conditions permit. In January 2019, the Ministry of Ecology and Environment issued the "Technical Guidelines for Groundwater Remediation in Contaminated Sites (Draft for Comment)", which requires that in areas with relatively heavy groundwater pollution, in areas with complex hydrogeological conditions such as multiple groundwater aquifers or aquifer thickness exceeding 6m, denser layout of monitoring points is required, and it is advisable to set up groundwater layered monitoring wells. On March 18, 2019, the Ministry of Ecology and Environment, the Ministry of Natural Resources, the Ministry of Housing and Urban-Rural Development, the Ministry of Water Resources, and the Ministry of Agriculture and Rural Affairs issued the "Implementation Plan for Groundwater Pollution Prevention and Control" (Environmental Soil

[2019] No. 25). The "Technical Specifications for Groundwater Environment Monitoring HJ 166-2020" (Draft for Comment) is divided into single-pipe single-layer monitoring wells, single-pipe multi-layer monitoring wells (i.e., the groundwater environment layered monitoring wells mentioned above), nested monitoring wells, and cluster monitoring wells according to the structural types of monitoring wells, and points out that when the aquifer contains non-aqueous phase pollution fluid such as LNAPL and DNAPL, or when there is a risk of cross-layer pollution in multiple aquifers, groundwater environment layered monitoring needs to be carried out.

[0005] A series of research and development on groundwater environment layered monitoring technologies have been carried out at home and abroad. Invention patents such as "A Gas-Pushed Underground Fluid Layered Sampling Device" (103967486B) and "Underground Fluid Layered Sampling Device and Method Based on U-Tube Technology (105298490B)" provide underground water layered sampling technologies based on the U-tube principle, and have developed three series of groundwater U-tube layered sampling devices for shallow (30m), medium (200m), and deep (2000m). Invention patents such as "A Pipe-in-Pipe Underground Fluid Layered Sampling Device" and utility model patent "An Underground Water Layered Monitoring Well Applicable to Multiple Aquifers" (208350783U) provide gas-driven underground water layered sampling technologies based on the pipe-in-pipe principle, doubling the number of layers of groundwater environment layered monitoring under the original conditions compared with the U-tube technology.

[0006] Although significant progress has been made in groundwater environment layered monitoring technologies and groundwater environment automated and intelligent monitoring technologies in recent years, the two have not been well integrated to form an automated groundwater environment layered monitoring technology. The main reasons are that the narrow space in the underground of a single-pipe multi-layer monitoring well cannot well integrate automated monitoring equipment. In addition, due to the limitations of the working principle and structural design of the multi-layer monitoring well in one hole, it cannot be well compatible with automated monitoring equipment.

[0007] As mentioned above, the groundwater environment layered monitoring wells are not yet automated and intelligent, and there are still several technical difficulties. Against this background, the present invention is developed based on the gas drive principle, expands the narrow underground space by reducing the number of pipelines, and combines the improvement of the multi-layer monitoring well structure in one hole, and attempts to provide an automated groundwater environment layered monitoring well applicable to contaminated sites. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide an automated multi-parameter groundwater environment layered monitoring well applicable to contaminated sites, especially applicable to environmental monitoring and environmental risk assessment at the site scale, and applicable to constructing a network of groundwater environment monitoring well groups at the site scale.

[0009] To solve the above technical problems, the technical solution adopted by the present invention is:

[0010] An automated multi-parameter groundwater environment layered monitoring well applicable to contaminated sites, including a drilling well and a packer. The multi-layer aquifers in the drilling well are sealed by the packer, and an aquifer layered sampling device is arranged in the aquifer.

[0011] The aquifer layered sampling device includes a first diversion pipe, a first three-way joint, a first check valve, a second check valve, a first downhole air-driven mechanism, a first pressure relief valve, a first threaded-to-NPT joint, a second threaded-to-NPT joint, a first downhole flow storage container, a third threaded-to-NPT joint, a third check valve, and a first filtration and dialysis assembly.

[0012] The first filtration and dialysis assembly is connected to the third threaded-to-NPT joint through the third check valve. The third check valve conducts unidirectionally from bottom to top. The third threaded-to-NPT joint is arranged at the bottom of the first downhole flow storage container. The top of the first downhole flow storage container is provided with a first threaded-to-NPT joint and a second threaded-to-NPT joint. The first threaded-to-NPT joint is connected to the air outlet end at the bottom of the first downhole air-driven mechanism through the first pressure relief valve. The air inlet end at the top of the first downhole air-driven mechanism is connected to the first three-way joint through the second check valve. The second check valve conducts unidirectionally from top to bottom. The second threaded-to-NPT joint is connected to the first three-way joint through the first check valve. The first check valve conducts unidirectionally from bottom to top. The first three-way joint is communicated with the bottom end of the first diversion pipe.

[0013] The top end of the first diversion pipe passes through the drilling and extends to the ground. The top end of the first diversion pipe is connected to the relay device through a first ball valve. The relay device is connected to the pressure pump. The top end of the first diversion pipe is also sequentially connected to the sampling bottle through a second ball valve and the corresponding water quality flow detection pool. A ground sensor array is arranged in the water quality flow detection pool.

[0014] The automated multi-parameter groundwater environment layered monitoring well applicable to polluted sites further includes a first water level gauge arranged in each monitoring layer in the drilling for measuring water level, water temperature, and conductivity.

[0015] The automated multi-parameter groundwater environment layered monitoring well applicable to polluted sites further includes a solar panel, a rechargeable power supply, and a monitoring data acquisition and remote transmission module. The solar panel is connected to the rechargeable power supply. The rechargeable power supply is respectively connected to the pressure pump and the monitoring data acquisition and remote transmission module. The monitoring data acquisition and remote transmission module is respectively connected to the ground sensor array and the first water level gauge.

[0016] The present invention has the following beneficial effects compared with the prior art:

[0017] The present invention has been greatly improved and enhanced based on the prior groundwater U-shaped tube layered sampling technology and underground pipe-in-pipe layered sampling technology. It mainly solves the technical problem of water quality multi-parameter automation and can realize functions such as in-situ weak disturbance layered sampling of groundwater, automated layered sampling of groundwater, in-situ real-time monitoring in the well, and automated multi-parameter rapid detection of surface water quality. The specific advantages are as follows:

[0018] 1. The outstanding advantage lies in the realization of automated stratified monitoring of the groundwater environment. The gas-driven pressure source is a pressurizing pump, which accurately pressurizes through a fixed pressure value and a set sampling frequency to achieve automated stratified sampling of groundwater at multiple monitoring levels at different depths. It provides technical support for the remote automation and intelligence of groundwater environment monitoring wells and the construction of regional groundwater environment monitoring networks;

[0019] 2. Automated detection of multiple water quality parameters can realize in-situ monitoring of multiple groundwater quality parameters downhole (such as water level, water temperature, conductivity) or rapid detection at the wellhead (such as DO, pH, ORP, TDS, turbidity, etc.). The monitoring data is centrally stored and remotely transmitted automatically;

[0020] 3. Customized groundwater environment monitoring in stages and levels. The groundwater environment monitoring is carried out in three levels: in-situ automated monitoring downhole, rapid automated detection of multiple water quality parameters on the ground, and in-situ automated stratified sampling of groundwater. At the first level, the water level, water temperature, and conductivity are monitored automatically in-situ downhole through a water level gauge to establish long-term groundwater monitoring data. At the second level, the parameters such as DO, PH, ORP, TDS, and turbidity of groundwater are rapidly detected through rapid automated detection of multiple water quality parameters on the ground. If characteristic pollutants or other emergency water events are detected, it can be reflected in stages and levels, and water quality detection sensors can be added or replaced as needed, the detection frequency can be encrypted, and the detection accuracy can be improved. At the third level, when characteristic pollutants are detected or other emergency water events exceed the detection capacity of the sensor array, the operation of automated stratified sampling of groundwater is encrypted, and the water samples are sent to the laboratory for fine analysis to meet the diverse needs of groundwater environment monitoring in stages and levels.

[0021] 4. Good representativeness of water samples. The structural design based on the gas-driven working principle ensures the high fidelity and representativeness of groundwater samples during the sampling process. For example, the interference of the sampling rate on the formation is reduced through the passive filtration and dialysis technology of groundwater downhole, and the sampling disturbance is small; the one-way valve cuts off the hydraulic connection between the sampling device pipeline and the original formation downhole, reducing the volatilization and dissipation of components.

[0022] 5. The downhole integration ability of the device is further improved. Compared with the U-shaped tube stratified sampling technology of groundwater, the number of pipelines per layer is reduced from 2 to 1, and under the same conditions, the rated sampling layers of the groundwater environment stratified monitoring device are doubled. By reducing the number of pipelines and the occupied space in the wellbore, the integration ability of the downhole monitoring module is improved, thus providing physical space and technical foundation for integrating more powerful downhole monitoring modules in the later stage.

[0023] 6. The present invention is mainly applicable to the investigation and monitoring of groundwater in the fields of site environmental monitoring and geological exploration, and is applicable to the "Technical Specification for Groundwater Environmental Monitoring" HJ 166 - 2020 promulgated by the Ministry of Ecology and Environment and the "Specification for Geological Survey and Evaluation of Groundwater Pollution" DD2008 - 01 promulgated by the Ministry of Natural Resources. In particular, it involves the fine layered monitoring of pollutants in a single aquifer, the construction of a regional groundwater environmental monitoring network, the monitoring of the dynamic changes of groundwater chemical characteristics in the vertical three-dimensional space over time, and the acquisition of long-term groundwater monitoring data. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic structural diagram of Example 1.

[0025] Figure 2 It is a schematic structural diagram of Example 2.

[0026] Figure 3 It is a pipeline distribution diagram on the ground.

[0027] In the figure:

[0028] 1.1. Solar panel (providing stable power on-site, a mature product, purchased on the market)

[0029] 1.2. Rechargeable power supply (providing stable power on-site, a mature product, purchased on the market)

[0030] 1.3. Monitoring data acquisition and remote transmission module (a mature product, purchased on the market)

[0031] 1.4. Ground sensor array (integrating water quality detection probes such as pH, DO, turbidity, ORP, conductivity, etc., purchased on the market)

[0032] 1.5. Water quality flow detection cell (flow cell, used for detecting water quality of flowing water, purchased on the market)

[0033] 1.6. Pressurizing pump; (the pressure application frequency and single pressure value can be set manually, purchased on the market)

[0034] 1.7. Relay device; (filling inert gas for displacement sampling, such as high-purity nitrogen with more than 99%)

[0035] 2a. First sampling bottle, 2b. Second sampling bottle; (standard sampling bottles of 50 ml or 1 L, purchased on the market)

[0036] 3. Power supply signal line; (used for supplying power to downhole sensors and transmitting signals, purchased on the market)

[0037] 4a. First diversion pipe, 4b. Second diversion pipe; (1 / 8 stainless steel pipe, 1 / 8 polyurethane hose or 4 mm air pressure hose, etc., purchased on the market)

[0038] 5.1a, the first three-way joint; 5.1b, the second three-way joint; 5.2a, the third three-way joint; 5.2b, the fourth three-way joint (PU pneumatic quick-connect fitting, purchased on the market)

[0039] 6.1a, the first check valve; 6.2a, the second check valve; 6.3a, the third check valve; 6.1b, the fourth check valve; 6.2b, the fifth check valve; 6.3b, the sixth check valve (only conducts unidirectionally and closes reversely, purchased on the market)

[0040] 7a, the first downhole gas drive mechanism; 7b, the second downhole gas drive mechanism (with good sealing performance and pressure-bearing capacity, does not leak under the pressure condition of 1 - 2 MPa. The material of the downhole gas drive mechanism has a certain elasticity and can perform corresponding volume expansion and contraction with the change of the internal pressure value. It has good durability and does not fatigue and damage after more than a thousand times of volume expansion and contraction.)

[0041] 8a, the first pressure relief valve; 8b, the second pressure relief valve (starts to relieve pressure after exceeding the set starting pressure value, purchased on the market)

[0042] 9.1a, the first thread-to-NPT adapter; 9.2a, the second thread-to-NPT adapter; 9.3a, the third thread-to-NPT adapter; 9.1b, the fourth thread-to-NPT adapter; 9.2b, the fifth thread-to-NPT adapter; 9.3b, the sixth thread-to-NPT adapter (thread-to-thread-to-NPT adapter, the size is selected according to the diameter of the diversion pipe, purchased on the market)

[0043] 10a, the first downhole fluid storage container; 10b, the second downhole fluid storage container; (the sampling volume depends on user requirements, 50 ml or 1 L, customized)

[0044] 11a, the first filtration and dialysis component; 11b, the second filtration and dialysis component; (filters sediment particles in groundwater, customized)

[0045] 12, the wellbore, (geological exploration well, exploration and production combined well, or hydrogeological monitoring well, including the wellhead on the ground and the shaft wall protection in the underground loose layer)

[0046] 13, the packer (bladder packer or mechanical packer, used for water stop and sealing, purchased on the market or customized)

[0047] 14a, the first water level gauge; 14b, the second water level gauge (downhole water level gauge probe, used for in-situ monitoring of groundwater level, water temperature, and conductivity, mature products on the market such as the American Insitu, Canadian Solinst, and Dutch Diver series)

[0048] 15.1a, First ball valve, 15.1b, Second ball valve, 15.2a, Third ball valve, 15.2b, Fourth ball valve (pneumatic quick-connect fitting ball valve, purchased on the market)

[0049] 16a, First cable, 16b, Second cable (conventional wire, connecting solar cell and electrical equipment). Detailed implementation manner

[0050] For the convenience of those of ordinary skill in the art to understand and implement the present invention, the present invention will be further described in detail below in conjunction with embodiments. It should be understood that the embodiments described herein are only used to illustrate and explain the present invention and are not used to limit the present invention.

[0051] Embodiment 1:

[0052] An automated multi-parameter groundwater environmental layered monitoring well applicable to polluted sites includes a drilling well and a packer 13. Multiple aquifers in the drilling well are sealed by the packer 13, and an aquifer layered sampling device is arranged in the aquifer.

[0053] The aquifer layered sampling device includes a first diversion pipe 4a, a first three-way joint 5.1a, a first check valve 6.1a, a second check valve 6.2a, a first downhole air drive mechanism 7a, a first pressure relief valve 8a, a first threaded male NPT joint 9.1a, a second threaded male NPT joint 9.2a, a first downhole flow storage container 10a, a third threaded male NPT joint 9.3a, a third check valve 6.3a, and a first filtration and dialysis assembly 11a.

[0054] The first filtration dialysis component 11a is connected to the third threaded NPT joint 9.3a through the third check valve 6.3a. The third check valve 6.3a conducts unidirectionally from bottom to top, that is, the third check valve 6.3a conducts unidirectionally from the first filtration dialysis component 11a to the third threaded NPT joint 9.3a. The third threaded NPT joint 9.3a is arranged at the bottom of the first downhole storage container 10a. The top of the first downhole storage container 10a is provided with a first threaded NPT joint 9.1a and a second threaded NPT joint 9.2a. The first threaded NPT joint 9.1a is connected to the air outlet end at the bottom of the first downhole air drive mechanism 7a through the first pressure relief valve 8a. The air inlet end at the top of the first downhole air drive mechanism 7a is connected to the first three-way joint 5.1a through the second check valve 6.2a. The second check valve 6.2a conducts unidirectionally from top to bottom, that is, the second check valve 6.2a conducts unidirectionally from the first three-way joint 5.1a to the first downhole air drive mechanism 7a. The second threaded NPT joint 9.2a is connected to the first three-way joint 5.1a through the first check valve 6.1a. The first check valve 6.1a conducts unidirectionally from bottom to top, that is, the first check valve 6.1a conducts unidirectionally from the second threaded NPT joint 9.2a to the first three-way joint 5.1a. The first three-way joint 5.1a is communicated with the bottom end of the first diversion pipe 4a.

[0055] The top end of the first diversion pipe 4a passes through the drilling and extends to the ground. The top end of the first diversion pipe 4a is connected to the relay device 1.7 through the first ball valve 15.1a. The relay device 1.7 is connected to the pressure pump 1.6. The top end of the first diversion pipe 4a also passes through the second ball valve 15.1b and the corresponding water quality flow detection pool 1.5 in sequence and is connected to the sampling bottle. A ground sensor array 1.4 is arranged in the water quality flow detection pool 1.5.

[0056] The automatic multi-parameter groundwater environment layered monitoring well applicable to contaminated sites further includes a first water level gauge 14a arranged in each monitoring layer in the drilling for measuring water level, water temperature and conductivity.

[0057] The automatic multi-parameter groundwater environment layered monitoring well applicable to contaminated sites further includes a solar panel 1.1, a rechargeable power supply 1.2 and a monitoring data acquisition and remote transmission module 1.3. The solar panel 1.1 is connected to the rechargeable power supply 1.2. The rechargeable power supply 1.2 is respectively connected to the pressure pump 1.6 and the monitoring data acquisition and remote transmission module 1.3. The monitoring data acquisition and remote transmission module 1.3 is respectively connected to the ground sensor array 1.4 and the first water level gauge 14a.

[0058] Embodiment 2:

[0059] The automatic multi-parameter groundwater environment layered monitoring well applicable to contaminated sites, such as Figure 2As shown in the figure, it includes an aquifer layered sampling device, an in-situ automatic groundwater monitoring device, and a real-time surface water quality detection device. Their specific connection methods are described as follows.

[0060] The groundwater automated layered sampling device includes a first aquifer layered sampling device and a second aquifer layered sampling device arranged in a drilling well. The first aquifer layered sampling device and the second aquifer layered sampling device are separated by a packer, and their upper and lower hydraulic connections are cut off by a packer 13 installed underground.

[0061] The first aquifer layered sampling device includes a first diversion pipe 4a, a first three-way joint 5.1a, a first check valve 6.1a, a second check valve 6.2a, a first downhole air drive mechanism 7a, a first pressure relief valve 8a, a first threaded adapter NPT joint 9.1a, a second threaded adapter NPT joint 9.2a, a first downhole storage container 10a, a third threaded adapter NPT joint 9.3a, a third check valve 6.3a, and a first filtration and dialysis component 11a.

[0062] The connection method of the first aquifer layered sampling device is as follows: from bottom to top, the first filtration and dialysis component 11a is connected to the third threaded adapter NPT joint 9.3a through a third check valve 6.3a (unidirectionally conducting from the first filtration and dialysis component 11a to the third threaded adapter NPT joint 9.3a), and the formed effective functional module filters, dialyzes, and isolates turbid particles and most microorganisms in the groundwater. The third threaded adapter NPT joint 9.3a is arranged at the bottom of the first downhole storage container 10a. The bottom of the first downhole storage container 10a is provided with a first threaded adapter NPT joint 9.1a and a second threaded adapter NPT joint 9.2a. The first threaded adapter NPT joint 9.1a is connected to the air outlet end at the bottom of the first downhole air drive mechanism 7a through a first pressure relief valve 8a. The air inlet end at the top of the first downhole air drive mechanism 7a is connected to the first three-way joint 5.1a through a second check valve 6.2a (unidirectionally conducting from the first three-way joint 5.1a to the first downhole air drive mechanism 7a). The second threaded adapter NPT joint 9.2a is connected to the first three-way joint 5.1a through a first check valve 6.1a (unidirectionally conducting from the second threaded adapter NPT joint 9.2a to the first three-way joint 5.1a). The first three-way joint 5.1a is communicated with the bottom end of the first diversion pipe 4a. The top end of the first diversion pipe 4a passes through the wellbore 12 at the top of the drilling well and extends to the ground, and is sequentially connected to a first sampling bottle 2a, a relay device 1.7, and a pressure pump 1.6. The pressure pump 1.6 located on the ground is connected to a solar charging power supply 1.2 through a first cable 16a for power supply, and cooperates with the relay device 1.7 to be connected to the first diversion pipe 4a of the first aquifer layered sampling device. Its function is to provide a pressure source for the hierarchical monitoring of the groundwater environment, with a set pressure value and pulse frequency (corresponding to the sampling frequency), and using high-purity nitrogen provided by the relay device as the pressure medium for air-driven sampling.

[0063] The layered sampling device for the second aquifer includes a second diversion pipe 4b, a second three-way joint 5.1b, a fourth check valve 6.1b, a fifth check valve 6.2b, a second downhole gas drive mechanism 7b, a second pressure relief valve 8b, a fourth threaded to NPT joint 9.1b, a fifth threaded to NPT joint 9.2b, a second downhole flow storage container 10b, a sixth threaded to NPT joint 9.3b, a sixth check valve 6.3b, and a second filtration and dialysis assembly 11b.

[0064] The connection method of the layered sampling device for the second aquifer is the same as that of the layered sampling device for the first aquifer, and the two are separated by a packer 13 set downhole to cut off the upper and lower hydraulic connection.

[0065] The connection method of the layered sampling device for the second aquifer is as follows: from bottom to top, the second filtration and dialysis assembly 11b is connected to the sixth threaded to NPT joint 9.3b through a sixth check valve 6.3b (unidirectionally conductive from the second filtration and dialysis assembly 11b to the sixth threaded to NPT joint 9.3b), and the formed effective functional module filters, dialyzes, and isolates the turbid particles and most microorganisms in the groundwater. The sixth threaded to NPT joint 9.3b is arranged at the bottom of the second downhole flow storage container 10b. The bottom of the second downhole flow storage container 10b is provided with a fourth threaded to NPT joint 9.1b and a fifth threaded to NPT joint 9.2b. The fourth threaded to NPT joint 9.1b is connected to the air outlet end at the bottom of the second downhole gas drive mechanism 7b through a second pressure relief valve 8b. The air inlet end at the top of the second downhole gas drive mechanism 7b is connected to the second three-way joint 5.1b through a fifth check valve 6.2b (unidirectionally conductive from the second three-way joint 5.1b to the second downhole gas drive mechanism 7b). The fifth threaded to NPT joint 9.2b is connected to the second three-way joint 5.1b through a fourth check valve 6.1b (unidirectionally conductive from the fifth threaded to NPT joint 9.2b to the second three-way joint 5.1b). The second three-way joint 5.1b is communicated with the bottom end of the second diversion pipe 4b. The top end of the second diversion pipe 4b passes upward through the packer 13 and extends to the ground, and is sequentially connected to the second sampling bottle 2b, the relay device 1.7, and the pressure pump 1.6. The pressure pump 1.6 located on the ground is connected to the solar charging power supply 1.2 through a first cable 16a for power supply, and is connected to the second diversion pipe 4b of the layered sampling device for the second aquifer in cooperation with the relay device 1.7. Its function is to provide a pressure source for the layered monitoring of the groundwater environment, with a set pressure value and pulse frequency (corresponding to the sampling frequency), and using the high-purity nitrogen provided by the relay device as the pressure medium for gas drive sampling.

[0066] The top end of the first diversion pipe 4a extends through the wellbore 12 to the ground and is connected to the third three-way joint 5.2a. The third three-way joint 5.2a is connected to the relay device 1.7 through the first ball valve 15.1a. The third three-way joint 5.2a is also sequentially connected to the first sampling bottle 2a through the third ball valve 15.2a and the corresponding water quality flow detection pool 1.5. A ground sensor array 1.4 is arranged in the water quality flow detection pool 1.5.

[0067] The top end of the second diversion pipe 4b extends through the wellbore 12 to the ground and is connected to the fourth three-way joint 5.2b. The fourth three-way joint 5.2b is connected to the relay device 1.7 through the second ball valve 15.1b. The fourth three-way joint 5.2b is also sequentially connected to the second sampling bottle 2b through the fourth ball valve 15.2b and the corresponding water quality flow detection pool 1.5. A ground sensor array 1.4 is arranged in the water quality flow detection pool 1.5.

[0068] The ground sensor array 1.4 is connected to the monitoring data acquisition and remote transmission module 1.3.

[0069] The relay device 1.7 is connected to the pressure pump 1.6. The water quality flow detection pool 1.5 is connected to the monitoring data acquisition and remote transmission module 1.3. The monitoring data acquisition and remote transmission module 1.3 is connected to the rechargeable power supply 1.2 through the second cable 16b. The rechargeable power supply 1.2 is connected to the pressure pump 1.6 through the first cable 16a. The rechargeable power supply 1.2 is connected to the solar panel 1.1.

[0070] In this embodiment, the in-situ automatic groundwater monitoring device includes a first water level gauge 14a and a second water level gauge 14b. The inside of the well is divided into a first aquifer and a second aquifer by a packer 13. The first water level gauge 14a and the first aquifer layered sampling device are both arranged in the first aquifer; the second water level gauge 14b and the second aquifer layered sampling device are both arranged in the second aquifer. The first water level gauge 14a and the second water level gauge 14b are both connected to the monitoring data acquisition and remote transmission module 1.3 through cables.

[0071] The function of the in-situ automatic groundwater monitoring device is to monitor the water level, water temperature, and conductivity of each groundwater aquifer in-situ and in real-time. It realizes long-term power supply in the wild in-situ through the rechargeable power supply 1.2 and the solar panel 1.1. The in-situ real-time monitoring data in the well (such as the water level, water temperature, and conductivity of the first aquifer and the second aquifer) is remotely transmitted to the control room through the monitoring data acquisition and remote transmission module 1.3.

[0072] Surface water quality real-time detection device, including a water quality circulation detection pool 1.5 corresponding to the first sampling bottle 2a and a water quality circulation detection pool 1.5 corresponding to the second sampling bottle 2b. The ground sensor array 1.4 installed in the water quality circulation detection pool 1.5 is used to detect water quality parameters such as DO, PH, ORP, TDS, conductivity, and turbidity of groundwater samples in real time. The water quality parameters are stored and remotely transmitted through the monitoring data acquisition and remote transmission module 1.3. It should be noted that the water quality detection parameter categories, accuracy, and frequency of the surface water quality real-time detection device have strong customized design and phased transformation characteristics. It can be customized according to the water quality conditions of the monitoring points, local pollution characteristics, and different phased requirements of the project, and the required water quality detection sensors can be arranged. According to the changes in the phased requirements of project monitoring, the corresponding sensor arrays can be conveniently increased or decreased, and the required detection accuracy and detection frequency can be modified.

[0073] The working mode of the first aquifer layered sampling device is as follows.

[0074] (1) Groundwater dialysis injection. The branch composed of the third check valve 6.3a and the first filtration dialysis component 11a below the first downhole storage container 10a receives the in-situ passive infiltration of groundwater in the formation into the first downhole storage container 10a. The first filtration dialysis component 11a is used to filter and dialysis to isolate particulate turbidity in the water, and the effective water sample storage is realized through the one-way conduction function of the third check valve 6.3a from bottom to top;

[0075] (2) Pressurized pump pulse drive. The high-purity nitrogen of the pressurized pump 1.6 and the relay device 1.7 is used as the pressure medium to provide downhole pulsed gas-driven sampling power for the first downhole storage container 10a in turn through the first diversion pipe 4a, the first three-way joint 5.1a, the second check valve 6.2a, the first downhole gas drive mechanism 7a, and the first pressure relief valve 8a. The first downhole gas drive mechanism 7a receives the pulsed pressure supply from the ground pressurized pump 1 through the second check valve 6.2a in a one-way conduction manner from top to bottom, and uses the pressure of the inert gas (such as high-purity nitrogen) provided by the relay device 2 as the pressure drive medium to drive the groundwater sample in the first downhole storage container 10a.

[0076] (3) Groundwater sample displacement and transportation. The first downhole storage container 10a realizes the groundwater sampling and transportation through the first check valve 6.1a, the first three-way joint 5.1a, and the first diversion pipe 4a. After the pressure of the first downhole gas drive mechanism 7a accumulates to the starting pressure value set by the first pressure relief valve 9.1a, it starts to relieve pressure at the lower end. Under the pulsed pressure drive of the first downhole gas drive mechanism 7a with nitrogen as the medium, the groundwater sample is transported upward to the ground through the first check valve 6.1 of this branch and sent to the first sampling bottle 2a;

[0077] The working mode of the second-layer aquifer layered sampling device is the same as that of the first-layer aquifer layered sampling device, which is briefly described as follows: The pressure pump 1 uses the high-purity nitrogen gas of the relay device 2 as the pressure medium and unidirectionally conducts from top to bottom through the fifth check valve 6.2b into the gas drive branch to supply high-purity nitrogen gas pressure to the second downhole gas drive mechanism 7b of the pulse drive branch. After the pressure of the second downhole gas drive mechanism 7b accumulates to the starting pressure value set by the second pressure relief valve 9.1b, it starts to release pressure at the lower end, driving the groundwater sample in the second downhole storage container 10b to be transmitted to the ground sampling bottle 3 through the fourth check valve 6.1b of the groundwater sampling and transportation branch, thus completing the sampling of the second aquifer.

[0078] Rapid multi-parameter detection of groundwater samples at the wellhead. The groundwater samples enter the corresponding water quality flow detection pool 1.5 through the first diversion pipe 4a and the second diversion pipe 4b. The ground sensor array 1.4 in the water quality flow detection pool 1.5 detects multi-parameters of the water quality, including DO, PH, ORP, TDS, turbidity, etc. The detection data is remotely wirelessly transmitted to the control room through the monitoring data acquisition and remote transmission module 1.3;

[0079] In-situ automatic groundwater monitoring device. The first water level gauge 14a and the second water level gauge 14b in-situ and real-time monitor the groundwater level, water temperature, and conductivity. The monitoring data is remotely wirelessly transmitted to the control room through the monitoring data acquisition and remote transmission module 1.3.

[0080] When sampling different aquifers, strict well washing operations need to be carried out, and the pipelines need to be switched and the sampling bottles need to be replaced. Generally, the first two water samples are for well washing operations, and the third is for formal groundwater sampling.

[0081] The method for sampling using the above-mentioned automated multi-parameter groundwater environment layered monitoring well applicable to polluted sites includes the following steps:

[0082] Step 1, equipment assembly. Specifically, assemble the groundwater automated layered sampling device, the groundwater in-situ automatic monitoring device, and the surface water quality real-time detection device.

[0083] Step 2, equipment lowering into the well. The drill rig drills to the specified depth and replaces the well with clean water for 30 minutes. Lower the first-layer aquifer layered sampling device, the second-layer aquifer layered sampling device, the first water level gauge, and the second water level gauge into the well and set the packer;

[0084] Step 3, formation isolation. Start the packer to cut off the hydraulic connection between the upper and lower sampling horizons;

[0085] Step 4, in-situ real-time monitoring of groundwater level, water temperature, and conductivity through the first water level gauge and the second water level gauge. In-situ real-time monitoring of groundwater is carried out through the first water level gauge and the second water level gauge with three parameters set downhole to obtain long-term groundwater monitoring data;

[0086] Step 5: Automatically wash the groundwater well. Pressurize the stratified sampling device for the first aquifer and the stratified sampling device for the second aquifer through a pressure pump. When the starting pressure values of the first pressure relief valve 8a and the second pressure relief valve 8b are reached, start gas to drive the first downhole flow storage container 10a and the second downhole flow storage container 10b, and transfer the groundwater sample to the corresponding sampling bottle on the ground, thus completing the operation of in-situ weak disturbance groundwater well washing;

[0087] Step 6: Rapidly detect multi-parameters of surface water quality. After the groundwater well washing operation is completed, the groundwater sample is transported through the water quality circulation detection pool corresponding to the sampling bottle, and the set surface sensor array performs multi-parameter detection of water quality, including parameters such as DO, PH, ORP, TDS, turbidity, etc. The data is centrally stored and remotely transmitted through the monitoring data acquisition and remote transmission module;

[0088] Step 7: Automatically sample groundwater in layers. Based on the data of in-situ real-time monitoring of groundwater downhole in Step 4 and the rapid detection of multi-parameters of surface water quality in Step 6, set the groundwater sampling quantity and sampling frequency in combination with the local groundwater pollution situation and project requirements. Then, after performing the automatic groundwater well washing operation according to Step 5, repeat Step 5 and seal the water sample into the corresponding sampling bottle to complete the automatic groundwater sampling operation. For different sampling layers, repeat the above steps to complete the automatic groundwater layered sampling operation.

[0089] Step 8: Conduct on-site tests and send samples to the laboratory for inspection. Conduct necessary test analysis on the groundwater samples on-site. Pretreat the water samples sent to the laboratory for testing and analysis, such as on-site filtration, titration of acid-base protective agents, sealing and packaging with special reagent bottles, sample identification, etc. Handle the transportation of water sample specimens according to the specifications. Some samples are stored and transported at a constant temperature of 4 °C and sent to the laboratory for analysis and testing within 24 hours or 7 days.

[0090] Step 9: Reset the monitoring well device. After the identification and shipment of the automatically collected groundwater samples are completed, place new sampling bottles on-site. Check each device of the automatic multi-parameter groundwater environment layered monitoring well applicable to the polluted site, debug and replace, and maintain the placement state until the next cycle.

[0091] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Those skilled in the art of the present invention can make various modifications or supplements to the described specific embodiments or use similar methods to replace them, but will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. An automated multi-parameter groundwater environmental layered monitoring well applicable to contaminated sites, comprising a drilling well and a packer (13), characterized in that, Multiple aquifers in the wellbore are sealed off by a packer (13), and an aquifer layer sampling device is provided in the aquifer. The aquifer layer sampling device includes a first diversion pipe (4a), a first three-way joint (5.1a), a first check valve (6.1a), a second check valve (6.2a), a first downhole gas drive mechanism (7a), a first pressure relief valve (8a), a first threaded to NPT joint (9.1a), a second threaded to NPT joint (9.2a), a first downhole flow storage container (10a), a third threaded to NPT joint (9.3a), a third check valve (6.3a), and a first filtration and dialysis assembly (11a). The first filtration and dialysis assembly (11a) is connected to the third threaded to NPT joint (9.3a) through the third check valve (6.3a). The third check valve (6.3a) conducts unidirectionally from bottom to top. The third threaded to NPT joint (9.3a) is provided at the bottom of the first downhole flow storage container (10a). The top of the first downhole flow storage container (10a) is provided with a first threaded to NPT joint (9.1a) and a second threaded to NPT joint (9.2a). The first threaded to NPT joint (9.1a) is connected to the air outlet end at the bottom of the first downhole gas drive mechanism (7a) through the first pressure relief valve (8a). The air inlet end at the top of the first downhole gas drive mechanism (7a) is connected to the first three-way joint (5.1a) through the second check valve (6.2a). The second check valve (6.2a) conducts unidirectionally from top to bottom. The second threaded to NPT joint (9.2a) is connected to the first three-way joint (5.1a) through the first check valve (6.1a). The first check valve (6.1a) conducts unidirectionally from bottom to top. The first three-way joint (5.1a) is communicated with the bottom end of the first diversion pipe (4a). The top end of the first diversion pipe (4a) passes through the wellbore and extends to the ground. The top end of the first diversion pipe (4a) is connected to a relay device (1.7) through a first ball valve (15.1a). The relay device (1.7) is connected to a pressure pump (1.6). The top end of the first diversion pipe (4a) also passes through a second ball valve (15.1b) and a corresponding water quality flow detection pool (1.5) in sequence and is connected to a sampling bottle. A ground sensor array (1.4) is provided in the water quality flow detection pool (1.5). It also includes a first water level gauge (14a) provided in each monitoring layer in the wellbore for measuring water level, water temperature, and conductivity. It also includes a solar panel (1.1), a rechargeable power supply (1.2), and a monitoring data acquisition and remote transmission module (1.3). The solar panel (1.1) is connected to the rechargeable power supply (1.2). The rechargeable power supply (1.2) is respectively connected to the pressure pump (1.6) and the monitoring data acquisition and remote transmission module (1.3). The monitoring data acquisition and remote transmission module (1.3) is respectively connected to the ground sensor array (1.4) and the first water level gauge (14a). The branch path composed of the third check valve (6.3a) and the first filtration and dialysis component (11a) below the first downhole storage container (10a) receives the in-situ passive infiltration of groundwater from the formation into the first downhole storage container (10a). The nitrogen gas provided by the relay device sequentially passes through the first diversion pipe (4a), the first three-way joint (5.1a), the second check valve (6.2a), the first downhole gas drive mechanism (7a), and the first pressure relief valve (8a) to provide downhole pulsed gas drive sampling power for the first downhole storage container (10a). After the pressure of the first downhole gas drive mechanism (7a) accumulates to the starting pressure value set by the first pressure relief valve, it starts to release pressure at the lower end. Under the pulsed pressure drive of the first downhole gas drive mechanism (7a) with nitrogen gas as the medium, the groundwater sample is transported upward to the ground through the first check valve (6.1) and sent to the first sampling bottle (2a).

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