A shallow groundwater fixed-depth sampling device and sampling method without building a well

Abstract

The present invention provides a shallow groundwater fixed-depth sampling device and a sampling method thereof without the need for well construction, including a drilling casing and a water intake system; the drilling casing is a hollow steel pipe with a disposable percussion drill bit at the lower end, and the upper end is connected to a direct-push drilling rig through a pipe cap, and multiple sections of casing are connected as the drilling depth increases; the water intake system includes a built-in water filter pipe, a built-in connecting pipe, and a surface water pump; the upper layer is sealed and water-stopped by the drilling casing, and the filter material and the water filter pipe filter the groundwater at the target depth, thereby realizing the collection of groundwater samples within a determined depth range without the need for well construction. The present invention can solve the problem that the sampling depth of conventional groundwater monitoring wells is unclear and water-stopping is difficult, leading to cross-contamination of groundwater at different layers. The beneficial effects of the present invention are: ① Groundwater sampling without well construction can be achieved by using a direct-push drilling rig, reducing the waste and potential pollution of materials such as well pipes; ② Targeted groundwater sampling at the target depth can realize accurate investigation of groundwater pollution, which is conducive to accurate remediation of groundwater pollution.

Description

Technical Field

[0001] The invention relates to the technical field of environmental protection, and provides a shallow groundwater fixed-depth sampling device and a sampling method thereof without the need for building a well. Background Art

[0002] With the acceleration of industrialization and urbanization in my country, groundwater pollution is becoming increasingly prominent. To investigate groundwater environmental quality and the distribution of pollutants, groundwater sampling and analysis are necessary. Groundwater environmental surveys on construction sites primarily focus on shallow, unconfined aquifers. Currently, the primary method for environmental monitoring of shallow groundwater involves constructing groundwater environmental monitoring wells.

[0003] Shallow groundwater has varying distributions of pollutants at different depths, influenced by factors such as the location of pollution sources, geological conditions, and hydrogeological conditions. Groundwater environmental surveys require sampling of groundwater from aquifers at different depths to determine the distribution and depth of groundwater contamination. The accuracy of groundwater sampling using groundwater monitoring wells is affected by the standardization and quality of well construction. During well construction, well walls can easily collapse, leading to clogging of the well pipe at the bottom and ineffective filling of filter packing, making it difficult to collect representative groundwater samples. Furthermore, improper filling of water-stopping materials during well construction can lead to cross-contamination of groundwater at different depths, making it difficult to collect groundwater samples at a specific depth. Furthermore, sampling groundwater at different depths requires constructing multiple monitoring wells at varying depths, which is labor-intensive and costly. Existing methods for constructing monitoring wells to collect groundwater often result in the pipe and packing being left behind, resulting in material waste and the potential for secondary contamination. Therefore, the development of a shallow groundwater sampling device and method that eliminates the need for well construction is crucial. Summary of the Invention

[0004] The present invention aims to address the shortcomings of current conventional groundwater monitoring wells, such as unclear sampling depth and difficulty in stopping water, which leads to cross-contamination of groundwater in different layers. It provides a shallow groundwater fixed-depth sampling device that does not require well construction and a method for fixed-depth sampling using the device.

[0005] In order to solve the above technical problems, the present invention mainly adopts the following technical solutions:

[0006] A shallow groundwater fixed-depth sampling device that does not require well construction includes a drilling casing and a water intake system; the drilling casing is a hollow steel pipe and is used in conjunction with a direct-push drilling rig; the water intake system includes a built-in water filter pipe, a built-in connecting pipe, filter material, a water intake hose and a low-flow airbag pump.

[0007] In some embodiments disclosed in the present invention, the drilling casing includes a first section of drilling casing and several extended drilling casings. A disposable impact drill bit is installed at the bottom end of the first section of drilling casing, and the top end of the first section of drilling casing can be threadedly connected to an extended drilling casing or a pipe cap; a sealing ring is installed at the threaded connection of the drilling casing.

[0008] Preferably, the inner diameter of the drilling casing is greater than 10 cm, which is 5 cm greater than the outer diameter of the built-in water filter pipe.

[0009] In some embodiments disclosed in the present invention, the built-in water filter pipe is a hollow steel pipe with gaps, the length of which is customized according to the target fixed-depth sampling interval, the bottom end is a buffer sealing plug, the top section is an open threaded interface, connected to the built-in connecting pipe, and the outer wall of the top connection is provided with a cross hollow disc, the diameter of the cross hollow disc is larger than the inner diameter of the bottom pipe mouth of the first section of the drilling casing.

[0010] Preferably, the inner diameter of the built-in water filter pipe is greater than 5 cm, and the seam width of the water filter section is less than 0.5 mm.

[0011] In some embodiments disclosed in the present invention, the built-in connecting pipe is a hollow seamless steel pipe, which has the same inner diameter and outer diameter as the built-in water filter pipe. The single section length of the built-in connecting pipe is the same as the length of the drilling casing, and both ends of the built-in connecting pipe are connecting threads.

[0012] In some embodiments disclosed herein, the upper end of the water intake hose is connected to a ground low-flow airbag pump, and the lower end thereof is located in the built-in water filter tube. Preferably, the water intake hose has a depth scale and an inner diameter of 0.5-1 cm.

[0013] In some embodiments disclosed herein, the filling height range of the filter material is consistent with the length of the built-in water filter tube. Preferably, the particle size of the filter material is 1-2 mm.

[0014] A method for sampling shallow groundwater at a fixed depth without building a well, which uses the aforementioned shallow groundwater sampling device at a fixed depth without building a well, comprises the following steps:

[0015] S1: Place the built-in water filter tube into the first section of drilling casing, use a direct push drill to drill the drilling casing downward, and use multiple sections of drilling casing to connect according to the depth requirements until the first section of drilling casing is at the target sampling depth;

[0016] S2: During the downward drilling of the casing, the upper end of the built-in water filter pipe is synchronously connected to the built-in connecting pipe;

[0017] S3: After the drilling casing reaches the target depth, the drilling casing is lifted upward with a maximum lifting stroke equal to the length of the built-in filter pipe. During the lifting process, pressure is applied from the ground to the top of the built-in connecting pipe to knock out the disposable percussion drill bit of the first section of the drilling casing, exposing the built-in filter pipe downward to the aquifer at the target depth.

[0018] S4: After the drilling casing is lifted, a filter material conduit is inserted from the ground into the gap between the drilling casing and the built-in connecting pipe, passed through the cross-shaped hollow disk at the top of the built-in water filter pipe, and the filter material is filled into the space around the built-in water filter pipe;

[0019] S5: Pass the water intake hose through the built-in connecting pipe to the built-in water filter pipe. After the groundwater passes through the filter material and enters the built-in water filter pipe, use a low-flow airbag pump and the water intake hose to collect groundwater samples at the target depth;

[0020] S6: After collecting groundwater samples at the target depth, lift the drilling casing, recover the built-in connecting pipe and built-in water filter pipe, seal the hole with bentonite and cement slurry, and complete the shallow groundwater environmental survey and fixed-depth sampling without building a well.

[0021] The present invention has the following beneficial technical effects:

[0022] (1) The direct-push drilling rig is used to realize groundwater sampling without building a well. The main components of the sampling device are reused, avoiding the repeated construction of monitoring wells, reducing the waste and potential pollution of materials such as well pipes, and reducing the cost of consumables.

[0023] (2) Targeted groundwater sampling at target depths, achieving sealing and water-stopping through mechanical structures, enabling accurate investigation of groundwater pollution, and facilitating accurate remediation of groundwater pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the composition and structure of a specific embodiment of a shallow groundwater fixed-depth sampling device without the need for well construction;

[0025] Figure 2 This is a structural schematic diagram of the drilling state of a specific embodiment of a shallow groundwater fixed-depth sampling device without well construction;

[0026] Figure 3 This is a structural diagram of the sampling state of a specific embodiment of a shallow groundwater fixed-depth sampling device without well construction;

[0027] Figure 4 It is a flow chart of the steps for sampling using a fixed-depth sampling device for shallow groundwater without the need to build a well.

[0028] The numbers in the figure are: 1. First section of drilling casing; 2. Disposable impact drill bit; 3. Sealing ring; 4. Extended drilling casing; 5. Direct pressure pipe cap; 6. Built-in water filter pipe; 7. Cross hollow disc; 8. Buffer sealing plug; 9. Built-in connecting pipe; 10. Water intake hose; 11. Low-flow airbag pump; 12. Filter material. DETAILED DESCRIPTION

[0029] The following describes the embodiments of the present invention by means of specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0030] Among them, the accompanying drawings are only for illustrative purposes and represent only schematic diagrams rather than actual pictures, and should not be understood as limiting the present invention. In order to better illustrate the embodiments of the present invention, some parts of the accompanying drawings may be omitted, enlarged or reduced, and do not represent the dimensions of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions may be omitted in the accompanying drawings.

[0031] See also Figure 1-3 , a shallow groundwater fixed-depth sampling device that does not require well construction, in this embodiment, mainly includes a drilling casing and a water intake system. The drilling casing includes a first section of drilling casing 1, a disposable percussion drill bit 2, a sealing ring 3, an extended drilling casing 4, and a direct pressure pipe cap 5. The first section of drilling casing 1 and the extended drilling casing 4 are both hollow steel pipes. After the direct pressure pipe cap 5 is installed on the upper end, a direct push drilling rig is used for drilling; a steel disposable percussion drill bit 2 is installed at the bottom end of the first section of drilling casing 1, and the top end is connected to another section of extended drilling casing 4 or pipe cap 5 through an external thread; a sealing ring 3 is installed at the connection of multiple sections of drilling casing; the inner diameter of the drilling casing is 11 cm, and the length of a single section is 1.5 m.

[0032] The water intake system includes a built-in water filter pipe 6, a built-in connecting pipe 9, a water intake hose 10, a low-flow airbag pump 11 and filter material 12. The built-in water filter pipe 6 is a hollow seamed steel pipe with an inner diameter of 6 cm, a seam width of the water filter section less than 0.5 mm, and a length of 1.5 m. The bottom end is a buffer rubber sealing plug 8, and the top end is an open threaded interface that can be connected to the built-in connecting pipe 9. There is a cross-hollowed disc 7 on the outer wall of the top connection, and the diameter of the disc is larger than the inner diameter of the bottom pipe opening of the first section of the drilling casing 1. The built-in connecting pipe 9 is a hollow seamless steel pipe with the same inner and outer diameters as the built-in water filter pipe 6. The length of a single section is the same as the length of the drilling casing, and both ends are connecting threads. The upper end of the water intake hose 10 is connected to the ground low-flow airbag pump 11, and the lower end is located in the built-in water filter pipe 6. The filling thickness of the filter material 12 is 1.5 m, and the particle size of the filter material is 1-2 mm.

[0033] See also Figure 4 , which are the steps for using the above device to conduct sampling at a fixed depth for shallow groundwater environment investigation:

[0034] Step 1: Place the built-in water filter pipe 6 into the first section of the drilling casing 1, use a direct push drill to drill the drilling casing 1 downward, and use multiple sections of extended drilling casing 4 to connect according to the depth requirements until the first section of the drilling casing 1 is at the target sampling depth;

[0035] Step 2: During the downward drilling of the casing, the upper end of the built-in water filter pipe 6 is synchronously connected to the built-in connecting pipe 9, as shown in FIG. Figure 2 As shown;

[0036] Step 3: After the drilling casing reaches the target depth, the drilling casing is lifted upwards with a maximum lifting stroke equal to the length of the built-in filter pipe 6. During the lifting process, pressure is applied to the top of the built-in connecting pipe 9 on the ground to knock out the disposable percussion drill bit 2 of the first section of the drilling casing 1, exposing the built-in filter pipe 6 downwards to the aquifer at the target depth;

[0037] Step 4: After the drilling casing is lifted, insert the filter material conduit from the ground into the gap between the drilling casing and the built-in connecting pipe 9, pass through the cross hollow disk 7 at the top of the built-in water filter pipe 6, and fill the filter material 12 into the space around the built-in water filter pipe 6;

[0038] Step 5: Pass the water intake hose 10 through the built-in connecting pipe 9 to the built-in water filter pipe 6. After the groundwater passes through the filter material 12 and enters the built-in water filter pipe 6, use the low-flow airbag pump 11 and the water intake hose 10 to collect groundwater samples;

[0039] Step 6: After collecting groundwater samples at the target depth, lift the drilling casing, recover the built-in connecting pipe 9 and the built-in water filter pipe 6, seal the hole with bentonite and cement slurry, and complete the shallow groundwater environmental survey and fixed-depth sampling without building a well.

Claims

1. A method for sampling shallow groundwater at a fixed depth without building a well, characterized in that: The shallow groundwater fixed-depth sampling device without well construction comprises a drilling casing and a water intake system; the drilling casing is a hollow steel pipe used in conjunction with a direct-push drilling rig; the water intake system comprises a built-in water filter pipe (6), a built-in connecting pipe (9), a filter material (12), a water intake hose (10) and a low-flow airbag pump (11); The drilling casing comprises a first section drilling casing (1) and a plurality of extended drilling casings (4); a disposable impact drill bit (2) is installed at the bottom end of the first section drilling casing (1); and the top end of the first section drilling casing (1) can be connected to an extended drilling casing (4) or a pipe cap through a threaded connection; a sealing ring (3) is installed at the threaded connection of the drilling casing; The built-in water filter pipe (6) is a hollow steel pipe with a gap, the length of which is customized according to the target fixed-depth sampling interval, the bottom end of which is a buffer sealing plug (8), the top section of which is an open threaded interface, connected to the built-in connecting pipe (9), and the outer wall of the top connection is provided with a cross hollow disk (7), the diameter of which is larger than the inner diameter of the bottom pipe opening of the first section of the drilling casing (1); The upper end of the water intake hose (10) is connected to the ground low-flow airbag pump (11), and the lower end thereof is located in the built-in water filter pipe (6). The water intake hose (10) has a depth scale and an inner diameter of 0.5-1 cm; The shallow groundwater fixed depth sampling method without well construction includes the following steps: Place the built-in water filter tube into the first section of drilling casing, use a direct push drill to drill the drilling casing downward, and use multiple sections of drilling casing to connect according to the depth requirements until the first section of drilling casing is at the target sampling depth; During the downward drilling process of the drilling casing, the upper end of the built-in water filter pipe is synchronously connected to the built-in connecting pipe; After the drilling casing reaches the target depth, the drilling casing is lifted upwards with a maximum lifting stroke equal to the length of the built-in water filter pipe. During the lifting process, pressure is applied to the top of the built-in connecting pipe on the ground to knock out the disposable percussion drill bit of the first section of the drilling casing, exposing the built-in water filter pipe downwards to the aquifer at the target depth. After the drilling casing is lifted, insert the filter material conduit from the ground into the gap between the drilling casing and the built-in connecting pipe, pass through the cross hollow disc on the top of the built-in water filter pipe, and fill the filter material into the space around the built-in water filter pipe; Pass the water intake hose through the built-in connecting pipe to the built-in water filter pipe. After the groundwater passes through the filter material and enters the built-in water filter pipe, use a low-flow airbag pump and the water intake hose to collect groundwater samples at the target depth. After collecting groundwater samples at the target depth, the drilling casing is lifted, the built-in connecting pipe and built-in water filter pipe are recovered, and the hole is sealed with bentonite and cement slurry to complete the shallow groundwater environmental survey and fixed-depth sampling without building a well.

2. The shallow groundwater fixed depth sampling method without well construction according to claim 1 is characterized in that: The inner diameter of the drilling casing is greater than 10 cm, which is 5 cm greater than the outer diameter of the built-in water filter pipe (6).

3. The method for sampling shallow groundwater at a fixed depth without building a well according to claim 1, wherein: The inner diameter of the built-in water filter pipe (6) is greater than 5 cm, and the width of the water filter section is less than 0.5 mm.

4. The method for sampling shallow groundwater at a fixed depth without building a well according to claim 1, wherein: The built-in connecting pipe (9) is a hollow seamless steel pipe having the same inner diameter and outer diameter as the built-in water filter pipe (6). The length of a single section of the built-in connecting pipe (9) is the same as the length of the drilling casing, and both ends of the built-in connecting pipe are connected with threads.

5. The method for sampling shallow groundwater at a fixed depth without building a well according to claim 1, wherein: The filling height range of the filter material (12) is consistent with the length of the built-in water filter pipe (6).

6. The method for sampling shallow groundwater at a fixed depth without building a well according to claim 1, wherein: The particle size of the filter material (12) is 1-2 mm.

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