Hydrogeological management system, well controller and method for managing water content of an aquifer

Abstract

The hydrogeological management system (1) for managing an aquifer (2) comprises: • a pump (6) configured to pump water out of or into the aquifer (2) via at least one well (4), the at least one pump (6) having a pump controller (8), • a Transient Electromagnetic Method (TEM) sensor (10) configured to issue TEM signals representative of at least one parameter in the aquifer (2), and • a well controller (12) configured for communicating with the TEM sensor (10) and the pump controller (8), and for: • analyzing the TEM signals issued during and / or after a defined pumping operation in which the pump (6) is pumping water out of or into the aquifer (2), • measuring changes in the analyzed TEM signals, • generating analysis signals representative of said changes, and • converting the analysis signals into control signals designed for controlling the at least one pump (6).

Description

HYDROGEOLOGICAL MANAGEMENT SYSTEM, WELL CONTROLLER AND METHOD FOR MANAGING WATER CONTENT OF AN AQUIFERTechnical field

[0001] The present disclosure is directed to a hydrogeological management system for managing water content of an aquifer. The present disclosure is further directed to a well controller. The present disclosure is also directed to a method for managing water content of an aquifer.Technical background

[0002] In the field of hydrogeological management of an aquifer, it is known to monitor the water table of the aquifer via the wells by implementing the Transient Electromagnetic Method (hereinafter "TEM"), which is explicated for example in the paper titled "The transient electromagnetic method"; authored by Christiansen, A.V., Auken, E., Sprensen, K. (2006); edited in: Kirsch, R. (eds) Groundwater Geophysics, Springer, Berlin, Heidelberg; and available at: https: / / doi.org / 10.1007 / 3-540-29387-6 6. The content of this paper is hereby incorporated by reference.

[0003] Traditionally, geology experts have used the TEM technology for determining the underground geology, in particular the mineral composition and the content of water reservoirs of an aquifer. When implementing the TEM technology to detect the different layers and water reservoirs, magnetic pulses are sent into the underground, and the strength of the induced pulses that comes back is monitored over time, for example by means of a standard equipment converting the induced pulses into a resistivity profile of the underground. In addition to the TEM signals that are thusly collected, a lot of information and knowledge about geology is needed to process and interpret data from the available TEM sensors before being able to properly manage the wells located on the aquifer.

[0004] However, converting the interpretation of data into usable knowledge requires a geology expert who brings additional knowledge about the underground. In order to establish a profile of the different layers of the aquifer, the geology expert will usually need prior knowledge about mineral composition in order to guess hypothesize the underground layer composition. Such fastidious collection and interpretation of data can only be made during an initial exploratory phase. Then water is pumped out of the aquifer, but it can lead to various problems. In particular, if an aquifer is not regularly monitored by a geology expert, and / or if pumping is not properly managed, then the well risk extracting water at a faster rate than the aquifer is refilled, which may in turn cause permanent damage to the aquifer or to the wells, like collapsing of the aquifer, land subsidence, drawing polluting substances or salt water into the wells.Summary

[0005] It is thus a first object of the present disclosure to provide a hydrogeological management system for managing water content of an aquifer and comprising:- at least one pump configured to pump water out of or into the aquifer via at least one well, the at least one pump having a pump controller,- at least one TEM sensor configured to issue TEM signals representative of at least one parameter in the aquifer, and- a well controller configured for communicating with the TEM sensor and with the pump controller, the well controller being further configured:- for analyzing the TEM signals issued during and / or after a defined pumping operation in which the at least one pump is pumping water out of or into the aquifer,- for measuring changes in the analyzed TEM signals,- for generating analysis signals representative of said changes, and- for converting the analysis signals into control signals designed for controlling the at least one pump.

[0006] Thus, the hydrogeological management system enables to partly or fully automatize the management of water in the aquifer without requiring expert knowledge of geology. The underground solid layers can be assumed to be static, so their position is not expected to change much over time. By contrast, the water table may be assumed to change over time, the more rapidly as the pumps are rapidly pumping water out of the aquifer. As the well controller measures changes in the analyzed TEM signals, the water table can be located in the underground layers and monitored. As a result, it becomes possible to ensure efficient pumping operations of groundwater without damaging the environment, the aquifer or the well. In the present disclosure the phrase "pumping water out of an aquifer" or its derivatives may be understood as meaning moving water out of the aquifer through a pump, while the phrase "pumping water into the aquifer" or its derivatives may be understood as meaning moving water toward the aquifer through a pump, hence in the opposite direction.

[0007] In some implementations, the well controller may be further configured to store and retrieve the analysis signals and / or to output the analysis signals.

[0008] In some implementations, the defined pumping operation may be defined by i) a time duration and ii) at least one pump operation parameter set during the time duration and selected among: power consumption, flow rate and speed.

[0009] Thus, the defined pumping operation can entail the pumping of a known volume of water out of the aquifer, against which the change of the aquifer may be correlated in order to accurately determine a change in the water table.

[0010] According to an embodiment, the well controller may be configured to send the analysis signals to the at least one pump controller during said defined pumping operation.

[0011] Thus, the pump controller can receive in real-time the control signals from the well controller.

[0012] According to an embodiment, the at least one pump controller may be configured for controlling pump operations following said defined pumping operation based on the analysis signals.

[0013] Thus, the pump controller can continuously control the at least one pump in accordance with the control signals issued by the well controller in relation to the defined pumping operation, which serves to calibrate the future pump operations.

[0014] According to an embodiment, the analyzed TEM signals may be time-stamped signals, and the well controller may be further configured to draw a comparison between the analysis signals and atleast one pump operation parameter measured among: power consumption, flow rate and speed, the well controller using the comparison for converting the analysis signals into the control signals.

[0015] As the time-stamped signals enable to evaluate the power consumption, the flow rate, and / or speed of the pump, it is possible to estimate how much water was pumped out of or into the aquifer during the defined pumping operation as well as during any subsequent pump operations. By combining the analysis signals with data about how the at least one pump runs and thus affects a water table of the aquifer over time, the well controller may automatically compare this combined information with the changes measured in the analyzed TEM signals, for example to determine absolute or relative changes in the water table over time.

[0016] Preferably, the well controller may include a microprocessor comprising a program that can be executed to carry out the operations that can be assigned to the well controller hereinbefore or hereinafter.

[0017] According to an embodiment, the well controller may be configured for generating the analysis signals such that the analysis signals are representative of changes of a water table of the aquifer.

[0018] Thus, the hydrogeological management system can be used to manage one or more pumps and possibly one or more wells, and to monitor the water table in the aquifer.

[0019] According to an embodiment, the well controller may be configured to analyze:- the TEM signals received before and after an initial defined pumping operation, and- the TEM signals received before and after each subsequent defined pumping operation.

[0020] Thus, the well controller can quickly compare, for each defined pumping operation, the TEM signals received before a defined pumping operation to the TEM signals received after the defined pumping operation. As a result, the well controller can monitor precisely the content of water in the aquifer.

[0021] According to an embodiment, the hydrogeological management system may further comprise at least one well fluidly connected to the aquifer, the at least one pump being arranged to pump water out of or into the aquifer via said at least one well, the at least one TEM sensor being preferably positioned near the at least one well.

[0022] Thus, the TEM signals from the sensor can accurately represent a parameter of the aquifer near the well.

[0023] According to an embodiment, the at least one TEM sensor may be arranged outside the at least one well, preferably above the ground under which the at least one well is located.

[0024] In some implementations, the or each TEM sensor may be positioned and the or a respective well may be separated by a distance of less than the extension of the aquifer. Besides, the well controller may associate each TEM sensor with a respective pump and, optionally, with a respective well.

[0025] According to an embodiment, the at least one TEM sensor may be arranged to be geostationary.

[0026] As the position of the TEM sensor is constant, the analysis signals generated by the well controller can be used over a long period, possibly over the whole period of service of the aquifer.

[0027] In some implementations, the well controller may be configured i) to receive meteorological information, such as rain fall data or air temperature and moisture, and ii) to use the meteorological information for converting the analysis signals into the control signals. Thus, the well controller can predict how rainfall can recharge the aquifer and how the capacity of a well might evolve.

[0028] In addition to generating the control signals, the well controller may be configured to send advices and alerts related to a state of the aquifer, preferably near a well. Thus, an operator may decide how the control set points of the pump located in this well may be further adjusted.

[0029] According to an embodiment, the hydrogeological management system may comprise:- a plurality of pumps configured to pump water out of or into the aquifer via a plurality of wells, each pump having a pump controller,- a plurality of TEM sensors configured to issue TEM signals representative of at least one parameter in the aquifer, all or part of the TEM sensors configured to be associated with respective wells out of the plurality of wells, and- the well controller may be configured for communicating with the TEM sensors and with the pump controllers, the well controller being further configured:- for analyzing the TEM signals issued during and / or after a defined pumping operation in which the pumps are pumping water out of or into the aquifer,- for measuring changes in the analyzed TEM signals,- for generating analysis signals representative of said changes, and- for converting the analysis signals into control signals designed for controlling the pumps.

[0030] Thus, the hydrogeological management system can be used to manage water content of a large portion or even of the whole the aquifer.

[0031] In some implementations, the well controller(s) may be configured i) to combine data from part or all of the plurality of TEM sensors and ii) to generate the control signals for controlling part or all of the plurality of pumps.

[0032] In some implementations, the pumps and, optionally, the wells may be distributed, for example uniformly, over a ground surface extending above the aquifer. In other words, the pumps, and possibly the wells, are arranged to form a lattice, which may be more or less uniform. Besides, all or some of the TEM sensors may be arranged outside the respective wells, preferably above the ground under which the wells is located.

[0033] In some implementations, the hydrogeological management system may comprise a plurality of well controllers, for example one well controller for each one of a plurality of wells.

[0034] According to a further embodiment, the plurality of pumps may comprise i) at least one pump configured to pump water into the aquifer via a respective well of the plurality of wells, and ii) at least one pump configured to pump water into the aquifer via a respective well of the plurality of wells.

[0035] Accordingly, there can be a pump for injecting water into the aquifer beside the pump(s) configured for drawing water from the aquifer. As for the drawing pump(s), the afore-mentioned control signals may be used for controlling the injecting pump. Thus, the injecting pump can inject water in the aquifer to avoid that salt water or a polluting substance water be drawn into the well ofthe drawing pump, which is undesirable for several reasons, in particular as it could damage the pump and possibly the well.

[0036] It is a second object of the present disclosure to provide a well controller comprising:- at least one interface for communicating with a TEM sensor and with a pump controller of at least one pump,- a computing module configured:- for analyzing the TEM signals that are representative of at least one parameter in the aquifer and that are issued by the TEM sensor during and / or after a defined pumping operation in which the at least one pump is pumping water out of or into the aquifer,- for measuring changes in the analyzed TEM signals,- for generating analysis signals representative of said changes, and- for converting the analysis signals into control signals suitable for controlling the at least one pump.

[0037] Thus, it becomes possible to ensure efficient pumping operations of groundwater without damaging the environment, the aquifer or the well and without requiring expert knowledge of geology.

[0038] It is a third object of the present disclosure to provide a method for managing water content of an aquifer, the method comprising:- implementing at least one pump configured to pump water out of or into the aquifer via at least one well, the at least one pump having a pump controller,- implementing at least one TEM sensor configured to issue TEM signals representative of at least one parameter in the aquifer, and- implementing a well controller configured for communicating with the TEM sensor and with the pump controller,- the well controller being further configured for communicating with the TEM sensor and with the pump controller, the well controller being further configured:- for analyzing the TEM signals issued during and / or after a defined pumping operation in which the at least one pump is pumping water out of or into the aquifer,- for measuring changes in the analyzed TEM signals,- for generating analysis signals representative of said changes, and- for converting the analysis signals into control signals suitable for controlling the at least one pump.

[0039] Thus, it becomes possible to ensure efficient pumping operations of groundwater without damaging the environment, the aquifer or the well and without requiring expert knowledge of geology.

[0040] According to an embodiment, the method may further comprise: sending the analysis signals to the pump controller during the execution of the defined pumping operation.

[0041] Thus, the pump controller can receive in real-time the control signals from the well controller.

[0042] The words "comprise", "include", "have" and their derivatives are to be interpreted inclusively rather than exclusively. The term "and / or" used in the context of "X and / or Y" should be interpreted as including all of "X," "Y," and "X and Y".Brief description of drawings

[0043] Further features, details and advantages of the present disclosure are described hereinafter, in particular in relation to the appended figures, which illustrate some of the afore-described aspects, embodiments and implementations thereof, and in which:

[0044] Fig.l is a schematic cross-sectional view showing a hydrogeological management system according to an embodiment, which is arranged over an aquifer and which comprises a plurality of wells and pumps;

[0045] Fig.2 is a schematic cross-sectional view showing a well and a pump of the hydrogeological management system of Fig.l during a defined pumping operation;

[0046] Fig.3A-3B are schematic graphs derived from TEM signals obtained with a TEM sensor of the hydrogeological management system of Fig.l;

[0047] Fig.4 is a schematic cross-sectional view showing a well and a pump of the hydrogeological management system of Fig.l before a pump operation;

[0048] Fig.5 shows a flowchart of a method for managing water content of an aquifer according to an embodiment and using for example the hydrogeological management system of Fig.l;

[0049] Fig.6 is a schematic cross-sectional view showing a well and a pump of the hydrogeological management system of Fig.l and showing the water table before and after an excessive pump operation;

[0050] Fig.7 is a schematic cross-sectional view showing two wells and two pumps of the hydrogeological management system of Fig.l during a pump operations and showing a mutual influence of the wells on the water table located between them;

[0051] Fig.8 is a schematic cross-sectional view showing a well and a pump of a hydrogeological management system according to another embodiment, which is arranged over an aquifer where salt water can be present;

[0052] Fig.9 is a schematic cross-sectional, taken along a different plane from Fig.8, showing the hydrogeological management system of Fig.8 which comprises two wells, a drawing pump and an injecting pump;

[0053] Fig.10 is a schematic graph similar to Fig.3B and deriving from TEM signals obtained with a TEM sensor of the hydrogeological management system of Fig.7; and

[0054] Fig.ll is a schematic cross-sectional view similar to Fig.10, showing a hydrogeological management system according to yet another embodiment, which is arranged over an aquifer containing a polluting substance and which comprises two wells, a drawing pump and an injecting pump.Detailed description

[0055] Fig.1 and 2 show a hydrogeological management system 1 for managing water content of an aquifer 2. The hydrogeological management system 1 of Fig.l comprises two pumps 6, which may be arranged respectively in two wells 4. The pump 6 are configured to pump water out of the aquifer 2 via the wells 4. The pumps 6 have respective pump controllers 8. One or more of the pump controller(s) 8 may be partly or fully embedded within or attached to the respective pumps 6. Alternatively, one or more of the pump controller(s) 8 may be arranged remotely from the pumps 6, preferably at a distance allowing communication with the pumps 6. For example, the pump controllers 8 may be arranged aboveground as illustrated in Fig.2. The wells 4 and the pumps 6 may be distributed, for example in a more or less uniform lattice, over the ground surface corresponding to the aquifer 2.

[0056] The hydrogeological management system 1 of Fig.l further comprises one or more TEM (Transient Electromagnetic Method) sensor(s) 10 configured to issue TEM signals representative of one or more parameter(s) in the aquifer 2, for example the level or altitude of the water table and positions of solid layers. Fig.3A and 3B show graphs derived from the TEM signals as detailed below. The TEM sensors 10 may be arranged outside the respective wells 4. Preferably, the TEM sensors 10 may be arranged above the ground under which the wells 4 are located.

[0057] The TEM sensor(s) 10 may comprise i) at least one transmitter 10.1 for sending magnetic pulses into an area to be monitored and ii) a receiver 10.2 for receiving the induced pulses coming back after reflecting and / or refracting on various layers of the aquifer 2. The transmitter 10.1 may comprise a transmitting coil and the receiver 10.2 may comprise a receiving coil, as described in the paper mentioned above and titled 'The transient electromagnetic method". The transmitter coil and / or the receiving coil may have a predetermined length and provide connectors suitable for quick connections. The transmitter 10.1 and the receiver 10.2 may be installed aboveground beside boreholes made for wells 4. The transmitter 10.1 and the receiver 10.2 may be powered by solar energy.

[0058] The hydrogeological management system 1 of Fig.l further comprises a well controller 12. The well controller 12 is configured for communicating with the TEM sensors 10 and with the pump controllers 8. The TEM sensors 10 may be associated with respective wells 4. As visible in Fig. 1, the or each well controller 12 may be part of a respective pump controller 8 and / or of a server, the server being preferably accessible remotely over a network e.g. the Internet. In case there are more than one well controller 12, the well controllers may preferably be configured to communicate with each other.

[0059] The well controller 12 may comprise an interface 12.1 for communicating with TEM sensors 10 and with pump controllers 8. The well controller 12 may further comprise a computing module 12.2 configured:- for analyzing the TEM signals issued during and / or after a defined pumping operation in which at least one of the pumps 6 is pumping water out of or into the aquifer 2,- for measuring changes in the analyzed TEM signals,- for generating analysis signals representative of said changes, and- for converting the analysis signals into control signals designed for controlling the pumps 6.

[0060] The well controller 12 may comprise hardware and / or software, which may be located on site and / or remotely, for example on a cloud linked to some of the components of the hydrogeologicalmanagement system 1. Accordingly, data like the TEM signals may be processed locally or remotely. The well controller 12 may be further configured to store and retrieve the analysis signals and / or to output the analysis signals. The well controller 12 may further be configured to send the analysis signals to the pump controller 8 during the defined pumping operation.

[0061] Fig.2 shows two water tables: a first water table 14.1 occurring before the pump 6 carries out a defined pumping operation, and a second water table 4.2 occurring during or after the defined pumping operation, wherein the defined pumping operation causes a cone of depression in the water table 4.2. As the TEM sensors 10 allow to monitor the water table in real time, the well controller 12 may, for example by means of a suitable algorithm, compare the first water table 14.1 to the second water table 4.2, determine how the defined pumping operation affects the water table in aquifer 2, and monitor precisely the content of water in the aquifer 2. In other words, the defined pumping operation may serve to calibrate the future pump operations.

[0062] The well controller 12 may be configured to analyze the TEM signals received before and after the initial, calibrating defined pumping operation. The well controller 12 may thus determine relative or absolute changes in the water table over time based on one or more parameter(s) characterizing the next pump operations. The well controller 12 may be configured for generating the analysis signals such that the analysis signals are representative of changes of the water table (from 14.1 to 14.2) of the aquifer 2.

[0063] The pump controller 8 may be configured for controlling pump operations following the defined pumping operation based on the analysis signals generated by the well controller 12. The defined pumping operation may be defined by a time duration and a pump operation parameter set during the time duration and selected among: power consumption, flow rate and speed of the pump 6.

[0064] The well controller 12 may be further configured i) to draw a comparison between the analysis signals and pump operation parameter measured, and ii) to use the comparison for converting the analysis signals into the control signals. So the defined pumping operation can result in the pumping of a known volume of water out of the aquifer 2 by pump 6, volume against which the change of the aquifer 2 may be correlated in order to accurately determine a change in the water table.

[0065] Fig.3A and 3B illustrate how the well controller 12 may analyze TEM signals from a TEM sensor 10 to determine where the water table 14.1 or 14.2 may be located. Fig.3A shows a schematic graph derived from TEM signals obtained with the TEM sensors 10. The horizontal axis in Fig.3A may represent the time t elapsing while measuring the TEM signals. So the horizontal axis is correlated with the depth at which the TEM signal may be reflected. The analyzed TEM signals may be time-stamped signals. The vertical axis in Fig.3A represents the amplitude S of a signal response of the TEM signals collected by a TEM sensor 10. The amplitude S may correspond to the voltage that is measured across the receiving coil and that may be shown in a logarithmic scale.

[0066] The curves in Fig.3A shows three variations SI, S2 and S3 in the signal response, which represent three respective operating points of the pump 6 during respective pump operations. The more water is being pumped out of aquifer 2, the more the water table 14.2 will drop. The signal response variation S3 represents the largest drop in the water table 14.2, hence the largest volume pumped out. The curve SO represents a baseline or a reference, that is, a signal response obtained when the pump 6 is not pumping (water table 14.1 in Fig.2).

[0067] On Fig.3B the curves SI, S2 and S3 have been subtracted from the baseline SO. Fig.3 B shows a flat baseline DSO and three peaks DS1, DS2 and DS3 corresponding respectively to curves SI, S2 andS3. The water table when no pump operations occur can be determined to be the point in time tO where the difference to the baseline SO start to occur. The right side of the signal in the curve can be used to determine how much the water table has dropped due to the respective pump operations SI, S2 and S3.

[0068] Fig.4 shows a well 4 and a pump 6 of the hydrogeological management system 1. The water table 14 and a bottom surface 16 of the aquifer 2 can be monitored, e.g. by a well controller 12 processing the TEM signals issued by a TEM sensor 10 placed on the ground G at some distance from the well 4. The TEM sensor 10 may be separated from the well 4 by e.g. a distance of less than 20 m. Besides, the TEM sensors 10 may be arranged to be geostationary, hence immobile with respect to the ground above the aquifer 2.

[0069] By monitoring a first level of water table 14.1 when pump 6 is pumping water out of aquifer 2 during a defined pumping operation, the well controller 12 can determine how fast the water table will decrease to a second level of water table 14.2. Further, after pump 6 has stopped pumping, the well controller 12 can determine how fast the of water table returns to the first level 14.1. From this information about a change in TEM signals from first 14.1 to second 14.2 levels of water table, the capacity of the well 4 can be determined quickly, instead of having a well driller measure the water level in the well 4. Such calibration process may be repeated until reaching a lower level 14.3 to provide a highly accurate measure of the capacity of the well 4 and of the hydraulic resistance (pressure drop) between the well 4 and an area of the aquifer 2 lying below sensor 10.

[0070] The pump 6 may be positioned at an optimal depth below water table 14.1 based on the information collected about capacity of the well 4 and how the water table drops as compared to the aquifer bottom 16. Pump operations of pump 6, e.g. as to the pump speed or the interval between pump operations, may be controlled based on this information. A preventive or corrective maintenance of the well 4 may also be proposed based on this information.

[0071] Fig.5 shows a method 101 for managing water content of aquifer 2, which method may be used to operate the hydrogeological management system 1 of Figs.l to 4. The method 101 may comprise:- 102) preferably, arranging the wells 4 with respect to the aquifer 2,- 104) preferably, fluidly connecting the wells 4 to the aquifer 2,- 106) implementing the pumps 6 to pump water out of aquifer 2 via the wells 4,- 108) implementing one or more TEM sensors 10 configured to issue TEM signals representative of a water table 4.2 in aquifer 2,- 110) issuing TEM signals by the TEM sensors 10,- 112) implementing the well controller 12 for communicating with the TEM sensors 10 and with the pump controller 8.The well controller 12 is further configured for communicating with the TEM sensors 10 and with the pump controller 8. As described above the well controller 12 is also configured:- 114) for analyzing the TEM signals issued during and / or after a defined pumping operation in which the pumps 6 are pumping water out of the aquifer 2,116) for measuring changes in the analyzed TEM signals,- 118) for generating analysis signals representative of said changes, and- 120) for converting the analysis signals into control signals suitable for controlling the pumps 6.The afore-listed operations may be carried out in a different order when technically feasible.

[0072] The method 101 may further comprise: 122) sending the analysis signals to the pump controller 8 during the execution of the defined pumping operation, such that the pump controller 8 can receive in real-time the control signals from the well controller 12.

[0073] Fig.6 shows a well 4 and a pump 6 of the hydrogeological management system 1 of Figs.l to 4 in a situation of overpumping, that is, where the aquifer 2 is being emptied over time much faster than water can refill it, with a water table dropping from a first level 14.1 to a much lower second level 14.2. In such a situation prolonging pump operations risks creating permanent damage to the underground of aquifer 2 in addition to preventing the aquifer 2 to recover a suitable capacity.

[0074] In duly managed pump operations, an elastic layer of aquifer 2 can drop and then reestablish itself during water recharge of aquifer 2. The well controller 12 may determine and monitor the level of such elastic layer by measuring changes in TEM signals. However, when the aquifer 2 does not reestablish itself, it could be a sign that the underground of aquifer 2 is compacting. A more compact underground has a higher resistivity, which the well controller 12 can measure. If it is determined that the aquifer 2 may be collapsing, then the well controller 12 may issue an alert and slow down or stop pump operations in order to avoid further damage, at least until the aquifer 2 gets refilled as the case may be.Conversely, if lowering the water table is desirable, e.g., during construction work or around houses where basement flooding is to be prevented, the sensor signal can also be used to control one or more pump(s) for proactively lowering the water table in a specific area. Thus, alternatively or additionally to the illustrated embodiments, a hydrogeological management system and / or a manging method according to the invention may be used for deliberately lowering the water table.

[0075] Fig.7 shows two wells 4 and two pumps 6 of the hydrogeological management system 1 of Fig.l in a partial overlapping of the respective cones of depression 18 caused by pumping by pumps 6. A TEM sensor 10 may be placed between the wells 4, for example in a medial position. The TEM sensor 10 may be associated with both wells 4 in order to monitor the water table 14.1 before a defined pumping operation and a water table 14.18 during of after pump operations.

[0076] During pump operations, the cones of depression 18 caused by pumping by the respective pumps 6 can be overlapping as the distance between the wells 4 is small. There can appear a mutual influence of the wells 4 on the water table 14.18 located between them. The well controller 12 may generate controlling signals to slow down pumps 6 if it is estimated that there could be a risk of overpumping amidst the wells 4 and reaching the level of the initial water table 14.1. Besides, the capacity from neighboring wells 4 can be balanced by the well controller 12.

[0077] Figs.8 to 10 show a hydrogeological management system 1 and well controllers 12 according to another embodiment. The hydrogeological management system 1 and the well controllers 12 of Fig.8 to 10 are similar to the ones depicted in relation to Figs.l to 7, apart from the following main differences. Like in the embodiment of Figs.1-7 the hydrogeological management system 1 of Figs.8- 10 comprises at least a well 4, a pump 6 and a TEM sensor 10.

[0078] By contrast to the previous embodiment, the hydrogeological management system 1 of Figs.8- 10 is arranged over an aquifer 2, in which fresh water (table 14) extends above a layer of salt water 22, which may exist in a coastal area.

[0079] As visible in Fig.9, the hydrogeological management system 1 of Figs.8-10 may comprise an injection well 54 and possibly an injecting pump 56, which are configured to pump water into the aquifer 2, hence to inject water into the aquifer 2. Accordingly, the pump 56 may circulate water in an opposite direction with respect to the pump 6: the pump 56 may pump water into aquifer 2 or "inwards", while the pump 6 may draw water out of aquifer 2 or "outwards". The injection well 54 may be arranged to supply water to an area between a dropping water table 22.1 of fresh water and an upper boundary of salt water 22 that is approaching the drawing pump 4 when pumping out of aquifer 2.

[0080] The injection well 54 may have a well controller 62. The detection of salt water 22 may be performed similarly to the detection of fresh water 14 described in relation to the previous figures, except that the electric conductivity of saltwater is much higher than the one of fresh water.

[0081] The graph in Fig.10 derives from TEM signals and, like Fig.3 B, it shows differences DS between i) baseline signals issued when no pumping occurs, and ii) TEM signals issued by TEM sensor 10 during defined pumping operations. The baseline signals DS0 and DS50 may be obtained when the pumps are stopped, like in Fig.3B. The TEM sensor 10 may help detect:- an upper level 14.1 of fresh water (no pumping),- a lower level 14.2 of fresh water (pumping),- an upper level 22.1 of salt water (pumping), which represents a boundary layer between fresh water and salt water 22, and- a lower level 22.2 of salt water (no pumping).

[0082] The three peaks on the left side of Fig.10 are identical as the peaks DS1, DS2 and DS3 of Fig.3B, and hence correspond to three increasing volumes of water pumped out of the aquifer 2. On the graph of Fig.10 the upper level 14.1 of fresh water can be read as a point L14.1, the lower level 14.2 of fresh water as a point L14.2, the upper level 22.1 of salt water as a point L22.1, and the lower level 22.2 of salt water as a point L22.2. The baseline signal DS0 (similar to DS0 in Fig.3B) stands for the fresh water. The downward bump DS50 on the right in the baseline represents the salt water.

[0083] The injection of fresh water induces three recesses DS5, DS6, DS7 below the baseline DS0 corresponding to three increasing volumes of water that get pumped into (i.e. supplied to or injected toward) the aquifer 2 by pump 56 during defined pumping operations. The well controller 62 may then convert the analysis signals DS5, DS6 and DS7 into control signals for controlling the injecting pump 56. The injecting pump 56 can inject water in the aquifer 2 to avoid that salt water 22 be drawn into the well 4 where the drawing pump 6 is pumping fresh water out of aquifer 2.

[0084] When the pump 6 in well 4 is pumping, the water table 14.1 decreases to a lower level 14.2. At the same time a boundary between fresh and salt water moves upward to an upper level 22.1. The well controller 62 may control the pump 56 to prevent that salt water comes into the well 4.

[0085] Fig.ll shows a hydrogeological management system 1 according to yet another embodiment. The hydrogeological management system 1 of Fig.ll is similar to the one depicted in relation to Figs.8 to 10, apart from the following main differences. Instead of salt water, the hydrogeological management system 1 is arranged over an aquifer 2 that contains polluted water 72.

[0086] Like in the embodiment of Figs.8-10, the hydrogeological management system 1 of Fig.ll comprises at least a well 4, a drawing pump 6, an injecting well 54, and a TEM sensor 10. Like in the embodiment of Figs.8-10, the injecting pump 56 may be arranged between the drawing pump 6 for clean water and the position of polluted water 72 to ensure that polluted water 72 is not drawn into the well 4.

[0087] By contrast to the embodiment of Figs.8-10, the injecting pump 56 may be used to lower the water table locally, in order to tilt it toward the polluted water 72, since water tend to flow towards areas having lower levels of water table. The injecting well 54 may be controlled to pump sufficient water into the aquifer 2 to ensure that the water table always tilts towards the polluted water 72. Further, to ensure that a gradient always exists while not or not much pumping water into the injection well 54, a pressure sensor may be placed in the injection well 54 to follow the level in the injection well 54, while a TEM sensor 10 is measuring the level of water at some distance of the injection well 54. More TEM sensors 10 may be used to establish a detailed surface view of the water table, to localize precisely the polluted water 72.

[0088] Depending on the localization and movements of the polluted water 72, more or less water may be injected into the aquifer 2 via one or more injection pump(s) 56 and injection well(s) 54. As the injection of fresh water might sometimes also affect the pumping of water via the well 4, the well controllers 12 and / or 62 may coordinate the amount of injected water to minimize the energy and quantity of water used for managing the injection well 54.

[0089] The present disclosure defined in the appended claims is not limited to the afore-described objects, aspects, embodiments and implementations, most of which may be combined whenever technically feasible.

Claims

CLAIMS1. Hydrogeological management system (1) for managing water content of an aquifer (2) and comprising:- at least one pump (6, 56) configured to pump water out of or into the aquifer (2) via at least one well (4, 54), the at least one pump (6, 56) having a pump controller (8),- at least one TEM, i.e., Transient Electromagnetic Method, sensor (10) configured to issue TEM, i.e., Transient Electromagnetic Method, signals representative of at least one parameter in the aquifer (2), and- a well controller (12, 62) configured for communicating with the TEM sensor (10) and with the pump controller (8), the well controller (12, 62) being further configured:- for analyzing the TEM signals issued during and / or after a defined pumping operation in which the at least one pump (6, 56) is pumping water out of or into the aquifer (2),- for measuring changes in the analyzed TEM signals,- for generating analysis signals representative of said changes, and- for converting the analysis signals into control signals designed for controlling the at least one pump (6, 56).

2. Hydrogeological management system (1) according to claim 1, wherein the well controller (12, 62) is configured to send the analysis signals to the at least one pump controller (8) during said defined pumping operation.

3. Hydrogeological management system (1) according to claim 1 or 2, wherein the at least one pump controller (8) is configured for controlling pump operations following said defined pumping operation based on the analysis signals.

4. Hydrogeological management system (1) according to any one of the preceding claims, wherein the analyzed TEM signals are time-stamped signals, and wherein the well controller (12, 62) is further configured to draw a comparison between the analysis signals and at least one pump operation parameter measured among: power consumption, flow rate and speed, the well controller (12, 62) using the comparison for converting the analysis signals into the control signals.

5. Hydrogeological management system (1) according to claim 4, wherein the well controller (12, 62) is configured for generating the analysis signals such that the analysis signals are representative of changes of a water table of the aquifer (2).

6. Hydrogeological management system (1) according to any one of the preceding claims, wherein the well controller (12, 62) is configured to analyze:- the TEM signals received before and after an initial defined pumping operation, and / or- the TEM signals received before and after each subsequent defined pumping operation.

7. Hydrogeological management system (1) according to any one of the preceding claims, further comprising at least one well (4, 54) fluidly connected to the aquifer (2), the at least one pump (6, 56) being arranged to pump water out of or into the aquifer (2) via said at least one well (4, 54), the at least one TEM sensor (10) being preferably positioned near the at least one well (4, 54).

8. Hydrogeological management system (1) according to claim 7, wherein the at least one TEM sensor (10) is arranged outside the at least one well (4, 54), preferably above the ground under which the at least one well (4, 54) is located.

9. Hydrogeological management system (1) according to any one of the preceding claims, wherein the at least one TEM sensor (10) is arranged to be geostationary.

10. Hydrogeological management system (1) according to any one of the preceding claims and comprising:- a plurality of pumps (6, 56) configured to pump water out of or into the aquifer (2) via a plurality of wells (4, 54), each pump (6, 56) having a pump controller (8),- a plurality of TEM sensors (10) configured to issue TEM signals representative of at least one parameter in the aquifer (2), all or part of the TEM sensors (10) being configured to be associated with respective wells (4, 54) out of the plurality of wells (4, 54), and wherein the well controller (12, 62) is configured for communicating with the TEM sensors (10) and with the pump controllers (8), the well controller (12, 62) being further configured:- for analyzing the TEM signals issued during and / or after a defined pumping operation in which the pumps (6, 56) are pumping water out of or into the aquifer (2),- for measuring changes in the analyzed TEM signals,- for generating analysis signals representative of said changes, and- for converting the analysis signals into control signals designed for controlling the pumps (6, 56).

11. Hydrogeological management system (1) according to claim 10,wherein the plurality of pumps (6, 56) comprises i) at least one pump (6, 56) configured to pump water into the aquifer (2) via a respective well (4, 54) of the plurality of wells (4, 54), and ii) at least one pump (6, 56) configured to pump water into the aquifer (2) via a respective well (4, 54) of the plurality of wells (4, 54).

12. A well controller (12, 62) comprising:- at least one interface (12.1) for communicating with a TEM, i.e., Transient Electromagnetic Method, sensor (10) and with a pump controller (8) of at least one pump (6, 56),- a computing module (12.2) configured:- for analyzing the TEM, i.e., Transient Electromagnetic Method, signals that are representative of at least one parameter in the aquifer (2) and that are issued by the TEM sensor (10) during and / or after a defined pumping operation in which the at least one pump (6, 56) is pumping water out of or into the aquifer (2),- for measuring changes in the analyzed TEM signals,- for generating analysis signals representative of said changes, and- for converting the analysis signals into control signals suitable for controlling the at least one pump (6, 56).

13. A method (101) for managing water content of an aquifer (2), the method (101) comprising:- implementing at least one pump (6, 56) configured to pump water out of or into the aquifer (2) via at least one well (4, 54), the at least one pump (6, 56) having a pump controller (8),- implementing at least one TEM, i.e., Transient Electromagnetic Method, sensor (10) configured to issue TEM, i.e., Transient Electromagnetic Method, signals representative of at least one parameter in the aquifer (2), and- implementing a well controller (12, 62) configured for communicating with the TEM sensor (10) and with the pump controller (8), the well controller (12, 62) being further configured for communicating with the TEM sensor (10) and with the pump controller (8), the well controller (12, 62) being further configured:- for analyzing the TEM signals issued during and / or after a defined pumping operation in which the at least one pump (6, 56) is pumping water out of or into the aquifer (2),- for measuring changes in the analyzed TEM signals,- for generating analysis signals representative of said changes, and- for converting the analysis signals into control signals suitable for controlling the at least one pump (6, 56).

4. Method (101) according to claim 13, further comprising: sending the analysis signals to the pump controller (8) during the execution of the defined pumping operation.

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