Determination of Storage Coefficients During Pumping and Recovery

Ashjari, Javad

doi:10.1111/j.1745-6584.2012.00917.x

Cited by 8 publications

(4 citation statements)

References 8 publications

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“…Additionally, for classical pumping tests, S cannot be obtained from the recovery data (residual drawdown) obtained after the completion of a pumping with the Theis or the Cooper-Jacob methods (Todd and Mays 2005). Some authors, nevertheless developed new methods to compute the storage coefficient from single-step pumping test recovery data (Banton and Bangoy 1996;Ashjari 2013), from multi-step pumping test recovery data (Lee and Lee 2000) or from the Agarwal recovery test method (Trabucchi et al 2018). However, all these methods require data from a piezometer.…”

Section: Computing the Aquifer Storage Coefficientmentioning

confidence: 99%

A cost-effective device and methodology to compute aquifer transmissivity and piezometry from free-flowing artesian wells

et al. 2022

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Artesian aquifers offer interesting opportunities for water supply by providing a low-vulnerability groundwater resource that is easily abstracted without any installation of pumps or power supply costs. However, hydraulic tests are challenging to perform, notably where the piezometric head is above ground level with free-flowing wells not equipped with valves and open for years. This paper describes a low-cost, easy to reproduce and adaptable device, the free-flowing artesian well device (FFAWD), which is mainly designed with a set of PVC tubes equipped with a pressure probe and a valve. This device is used to perform hydraulic tests on free-flowing artesian wells, to measure the piezometric head of the aquifer and to compute its transmissivity. The practical use of the FFAWD is described and a method is proposed to compute the piezometric head and the transmissivity of the aquifer from this data set (free-flowing well discharge and pressure increase measurements) with any adapted analytical solution, using the Houpeurt-Pouchan method. Artefacts such as post-production effects, surge effects, and the impact of a leaky well are identified to avoid any misinterpretation. The FFAWD was applied to the volcano-sedimentary artesian plain of Pasuruan (Indonesia). The advantages and limitations of using the device, along with the interpretation methodology, are also discussed.

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Section: Computing the Aquifer Storage Coefficientmentioning

confidence: 99%

A cost-effective device and methodology to compute aquifer transmissivity and piezometry from free-flowing artesian wells

et al. 2022

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“…The method is quite robust in estimating effective transmissivity values over a region that grows with the duration of pumping (Copty et al, 2011;Willmann et al, 2007) but lacks information about the storage coefficient. Numerous methods have been introduced to overcome this limitation (Agarwal, 1980;Ashjari, 2013;Ballukraya & Sharma, 1991;Banton & Bangoy, 1996;Chenaf & Chapuis, 2002;Çimen, 2015;Zheng et al, 2005), which suggests that recovery data contain information similar to that of the pumping phase of the test. Most of these methods are straight line methods based on CJ's approximation that allow evaluating hydraulic parameters but do not yield any information about the conceptual model.…”

Section: Research Articlementioning

confidence: 99%

Generalizing Agarwal's Method for the Interpretation of Recovery Tests Under Non‐Ideal Conditions

Trabucchi

Carrera

Fernàndez-García

2018

Water Resources Research

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Pumping tests are performed during aquifer characterization to gain conceptual understanding about the system through diagnostic plots and to estimate hydraulic properties. Recovery tests consist of measuring head response in observation and/or pumping wells after pumping termination. They are especially useful when the pumping rate cannot be accurately controlled. They have been traditionally interpreted using Theis' recovery method, which yields robust estimates of effective transmissivity but does not provide information about the conceptual model. Agarwal proposed a method that has become standard in the oil industry, to obtain both early and late time reservoir responses to pumping from recovery data. However, the validity of the method has only been tested to a limited extent. In this work, we analyze Agarwal's method in terms of both drawdowns and log derivatives for non‐ideal conditions: leaky aquifer, presence of boundaries, and one‐dimensional flow. Our results show that Agarwal's method provides excellent recovery plots (i.e., the drawdown curve that would be obtained during pumping) and parameter estimates for nearly all aquifer conditions, provided that a constant pumping rate is used and the log derivative at the end of pumping is constant, which is too limiting for groundwater hydrology practice, where observation wells are usually monitored. We generalize Agarwal's method by (1) deriving an improved equivalent time for time‐dependent pumping rate and (2) proposing to recover drawdown curves by extrapolating the pumping phase drawdowns. These yield excellent diagnostic plots, thus facilitating the conceptual model analysis for a broad range of conditions.

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“…They considered the residual drawdowns measurements from a single observation well. Ashjari [22] determined the transmissivity and storage coefficients from residual data in case of ̸ = by using a modified version of Banton and Bangoy [15] method. This method is basically fitting a straight-line to a plot of residual drawdown versus square of radial distance at the same time.…”

Section: Introductionmentioning

confidence: 99%

A Straight-Line Method for Analyzing Residual Drawdowns at an Observation Well

Çimen

2015

Mathematical Problems in Engineering

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Determination of the hydraulic parameters (transmissivity and storage coefficients) of a confined aquifer is important for effective groundwater resources. For this purpose, the residual drawdowns have been in use to estimate the aquifer parameters by the classical Theis recovery method. The proposed method of this paper depends on a straight-line through the field data and it helps to calculate the parameters quickly without any need for long-term pumping data. It is based on the expansion series of the Theis well function by consideration of three terms, and this approach is valid for the dimensionless time factoru′=S′r2/4Tt′≤0.2. The method can be applied reliably to extensive and homogeneous confined aquifers resulting in different storage coefficients during the pumping and recovery periodsS≠S′. It presents a strength methodology for the parameters decision making from the residual data in the groundwater field of civil engineering.

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Determination of Storage Coefficients During Pumping and Recovery

Cited by 8 publications

References 8 publications

A cost-effective device and methodology to compute aquifer transmissivity and piezometry from free-flowing artesian wells

A cost-effective device and methodology to compute aquifer transmissivity and piezometry from free-flowing artesian wells

Generalizing Agarwal's Method for the Interpretation of Recovery Tests Under Non‐Ideal Conditions

A Straight-Line Method for Analyzing Residual Drawdowns at an Observation Well

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