Feasibility of Monitoring Hydraulic Connections between Aquifers Using
                        Time-lapse TEM: A Case History in Inner Mongolia, China

Hydraulic connections between aquifers is usually studied through hydrochemical analysis or by pumping tests. However, hydrochemical analyses are usually conducted in areas of variable lithology. In addition, the hydrogeological data obtained by drilling and pumping tests are typically insufficient to get 3D distributions of hydraulic head. In this paper, the time-lapse transient electromagnetic method (TEM) is used to image groundwater migration between aquifers in Inner Mongolia, China. First, 1D geophysical models of aquifers are generalized according to the hydrogeological conditions of the region, and the feasibility of detecting the multiple aquifers by TEM is analyzed and discussed. Then, the 2D models of aquifers pre- and post- pumping test are established based on the distribution of groundwater in the aquifers, and the variation law of induced electromotive force measured on the surface is analyzed. The simulation results show that significant time-lapse electromagnetic anomalies can be observed between pre- and post- pumping test and the variation in the induced electromotive force reaches a distinguishable level between 0.7 ms and 100 ms due to the vertical change in the aquifer properties. Furthermore, the electromagnetic variation generated by hydraulic connection between aquifers is greater than 30% within the range of 3/4 of the transmitting loop. Finally, a successful case history to map hydraulic connections between aquifers is conducted using a time-lapse TEM pre- and post- a pumping experiment. This simulation and field experiment shows that time-lapse TEM could characterize and monitor the groundwater migration more effectively than pump tests or hydrogeochemical methods alone.

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Quantifying aquifer properties and freshwater resource in coastal barriers: a hydrogeophysical approach applied at Sasihithlu (Karnataka state, India)

Hydrology and Earth System Sciences ◽

10.5194/hess-16-4387-2012 ◽

2012 ◽

Vol 16 (11) ◽

pp. 4387-4400 ◽

Cited By ~ 17

Author(s):

J.-M. Vouillamoz ◽

J. Hoareau ◽

M. Grammare ◽

D. Caron ◽

L. Nandagiri ◽

...

Keyword(s):

Sea Level ◽

Groundwater Resources ◽

Time Lapse ◽

Unconfined Aquifer ◽

Spatial Knowledge ◽

Western India ◽

Transient Electromagnetic ◽

Freshwater Resource ◽

Aquifer Properties ◽

Rainfall Patterns

Abstract. Many human communities living in coastal areas in Africa and Asia rely on thin freshwater lenses for their domestic supply. Population growth together with change in rainfall patterns and sea level will probably impact these vulnerable groundwater resources. Spatial knowledge of the aquifer properties and creation of a groundwater model are required for achieving a sustainable management of the resource. This paper presents a ready-to-use methodology for estimating the key aquifer properties and the freshwater resource based on the joint use of two non-invasive geophysical tools together with common hydrological measurements. We applied the proposed methodology in an unconfined aquifer of a coastal sandy barrier in South-Western India. We jointly used magnetic resonance and transient electromagnetic soundings and we monitored rainfall, groundwater level and groundwater electrical conductivity. The combined interpretation of geophysical and hydrological results allowed estimating the aquifer properties and mapping the freshwater lens. Depending on the location and season, we estimate the freshwater reserve to range between 400 and 700 L m−2 of surface area (± 50%). We also estimate the recharge using time lapse geophysical measurements with hydrological monitoring. After a rainy event close to 100% of the rain is reaching the water table, but the net recharge at the end of the monsoon is less than 10% of the rain. Thus, we conclude that a change in rainfall patterns will probably not impact the groundwater resource since most of the rain water recharging the aquifer is flowing towards the sea and the river. However, a change in sea level will impact both the groundwater reserve and net recharge.

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2D-3D GPR as an efficient tool for paleoseismology: A successful case history across the Castrovillari fault (southern Apennines, Italy)

Proceedings of the 15th International Conference on Ground Penetrating Radar ◽

10.1109/icgpr.2014.6970566 ◽

2014 ◽

Author(s):

M. Ercoli ◽

C. Pauselli ◽

E. Forte ◽

R. Volpe ◽

C. Federico

Keyword(s):

Case History ◽

Southern Apennines ◽

Efficient Tool ◽

Successful Case ◽

3D Gpr

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Technical note: Analytical drawdown solution for steady-state pumping tests in two-dimensional isotropic heterogeneous aquifers

Hydrology and Earth System Sciences ◽

10.5194/hess-20-1655-2016 ◽

2016 ◽

Vol 20 (5) ◽

pp. 1655-1667 ◽

Cited By ~ 3

Author(s):

Alraune Zech ◽

Sabine Attinger

Keyword(s):

Steady State ◽

Correlation Length ◽

Heterogeneous Media ◽

Radial Distance ◽

Pumping Test ◽

Two Dimensional ◽

Aquifer Heterogeneity ◽

Pumping Tests ◽

Flow Solution ◽

Ensemble Mean

Abstract. A new method is presented which allows interpreting steady-state pumping tests in heterogeneous isotropic transmissivity fields. In contrast to mean uniform flow, pumping test drawdowns in heterogeneous media cannot be described by a single effective or equivalent value of hydraulic transmissivity. An effective description of transmissivity is required, being a function of the radial distance to the well and including the parameters of log-transmissivity: mean, variance, and correlation length. Such a model is provided by the upscaling procedure radial coarse graining, which describes the transition of near-well to far-field transmissivity effectively. Based on this approach, an analytical solution for a steady-state pumping test drawdown is deduced. The so-called effective well flow solution is derived for two cases: the ensemble mean of pumping tests and the drawdown within an individual heterogeneous transmissivity field. The analytical form of the solution allows inversely estimating the parameters of aquifer heterogeneity. For comparison with the effective well flow solution, virtual pumping tests are performed and analysed for both cases, the ensemble mean drawdown and pumping tests at individual transmissivity fields. Interpretation of ensemble mean drawdowns showed proof of the upscaling method. The effective well flow solution reproduces the drawdown for two-dimensional pumping tests in heterogeneous media in contrast to Thiem's solution for homogeneous media. Multiple pumping tests conducted at different locations within an individual transmissivity field are analysed, making use of the effective well flow solution to show that all statistical parameters of aquifer heterogeneity can be inferred under field conditions. Thus, the presented method is a promising tool with which to estimate parameters of aquifer heterogeneity, in particular variance and horizontal correlation length of log-transmissivity fields from steady-state pumping test measurements.

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A Successful Case History of Carbonate Acidizing for High H2S Gas Well in China

10.2118/183156-ms ◽

2016 ◽

Author(s):

Minh Vo ◽

Kevin Scott ◽

Chaohong Xiao ◽

Qiang Wang ◽

Zhengxing Dai ◽

...

Keyword(s):

Case History ◽

Gas Well ◽

Successful Case ◽

History Of ◽

Carbonate Acidizing

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Time-Lapse Seismic Monitoring in Carbonates - An Offshore Brazil Successful Case-Study

London 2013, 75th eage conference en exhibition incorporating SPE Europec ◽

10.3997/2214-4609.20130853 ◽

2013 ◽

Author(s):

M.H. Grochau ◽

F. Villaudy ◽

P.M. Benac ◽

L.M. Alvim ◽

R.C. Sansonowski ◽

...

Keyword(s):

Time Lapse ◽

Seismic Monitoring ◽

Successful Case

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Machine Learning Methods for Improved Understanding of a Pumping Test in Heterogeneous Aquifers

Water ◽

10.3390/w12051342 ◽

2020 ◽

Vol 12 (5) ◽

pp. 1342 ◽

Cited By ~ 1

Author(s):

Yong Fan ◽

Litang Hu ◽

Hongliang Wang ◽

Xin Liu

Keyword(s):

Machine Learning ◽

Time Series ◽

Time Series Analysis ◽

Analytical Solutions ◽

Pumping Test ◽

Learning Methods ◽

Pumping Tests ◽

Machine Learning Methods ◽

Series Analysis ◽

Pumping Wells

Pumping tests are very important means for investigating aquifer properties; however, interpreting the data using common analytical solutions become invalid in complex aquifer systems. The paper aims to explore the potential of machine learning methods in retrieving the pumping tests information in a field site in the Democratic Republic of Congo. A newly planned mining site with a pumping test of three pumping wells and 28 observation wells over one month was chosen to analyze the significance of machine learning methods in the pumping test analysis. Widely used machine learning methods, including correlation, cluster, time-series analysis, artificial neural network (ANN), support vector machine (SVR), random forest (RF) method, and linear regression, are all used in this study. Correlation and cluster analyses among wells provide visual pictures of possible hydraulic connections. The pathway with the best permeability ranges from the depth of 250 m to 350 m. Time-series analysis perfectly captured changes of drawdowns within the three pumping wells. The RF method is found to have the higher accuracy and the lower sensitivity to model parameters than ANN and SVR methods. The coupling of the linear regressive model and analytical solutions is applied to estimate hydraulic conductivities. The results found that ML methods can significantly and effectively improve our understanding of pumping tests by revealing inherent information hidden in those tests.

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