Results Of Pumping Tests Research Articles

Stratigraphic modeling and hydraulic characterization of a typical basaltic aquifer system in the Kadva river basin, Nashik, India

The primary objective of the study is to characterize the hydrogeologic status and identify the trend in groundwater storage of aquifer system to provide an improved understanding of the groundwater flow system in the Kadva river basin, India. This is accomplished by the integrated use of stratigraphic modeling, pressure derivative approach, and pumping test analysis. The results of the stratigraphic modeling indicate that the unconfined aquifer thickness ranging from 8.2 to 34.2 m and generally occur to the depth of 2.2–36.5 m below ground level (bgl), whereas semi-confined aquifer thickness ranges from 6.1 to 58.3 m and generally occurs 30.6 m bgl over the study area with an interconnected semi-confining unit of thickness ranging from 1.6 to 22.3 m. The pumping test results of unconfined aquifer in the study area show that the transmissivity varies from 15.66 to 98.18 m2/day, and the specific yield ranging from 8.2 × 10–4 to 3.2 × 10–2. Pumping test data and derivative analysis show that the deep aquifers are semi-confined with transmissivity ranging from 14.4 to 111.2 m2/day, storage coefficient varies from 1.56 × 10–4 to 4.83 × 10–4, and hydraulic resistance ranges from 93 to 1270 days. The values of hydraulic parameters revealed a remarkable spatial variability, suggesting that the basaltic aquifer system has strong heterogeneity. The results of the present study are helpful in the formulation of efficient policies for sustainable groundwater management in basaltic aquifers system in India in particular and worldwide in general.

Enhancement of groundwater yield by hydrofracturing technique: A case study from crystalline hard rock terrain

Hydrofracturing process was developed during the 1940s for improving the yield from oil and gas wells. Later this technique was adopted for water well development. The hydrofracturing process consists of pumping test before and after fracturing a well. The pre-fracturing and post-fracturing pumping test results are analysed and correlated to estimate the yield improvement realized due to fracturing. An attempt was made to improve the groundwater yield from a borewell in hard rock formation in Thachchur Village of Cuddalore District, Tamil Nadu, India. The pre-pumping static water level was 4.25 m below measuring point (bmp), and the safe yield was 5 litres per minute (lpm)/16 m drawdown/8 h of pumping per day. Hydrofracturing was carried out using a single packer assembly system, and two fracture zones lying at the depth of 15 m and 45 m were treated. After fracturing treatment, pumping test was carried out. Post-fracturing pumping test results revealed that the safe yield was 80 lpm/16 m drawdown/8 h of pumping per day. The yield improvement from 5 to 80 lpm substantiated the success of hydrofracturing in the hard rock borewell. The groundwater yield improvement in the borewell is due to the enlargement of fissures and cracks in and around the borewell by hydrofracturing.

On the Reliability of Variable‐Rate Pumping Test Results: Sensitivity to Information Content of the Recorded Data

AbstractPumping tests are widely used to estimate parameters such as transmissivity and storativity, using aquifer response equations that assume a time‐constant pumping rate. However, in actual practice the discharge rate will often vary erratically and follow a generally decreasing trend as the test proceeds. In such cases, if the discharge history is recorded with sufficient temporal fidelity, accurate solutions can be obtained via time domain piecewise‐linear numerical integration. However, if the discharge data do not adequately characterize the variability in the dynamics of the pumping rate, the result can be information loss leading to bias in the inferred parameter estimates. Here, we investigate the severity of this problem for six selected aquifer types, including those that are confined, leaky, and unconfined. Our results indicate that the effects of information loss due to inadequate temporal resolution of the discharge data and systematic observational error are significantly more severe than due to random observational error. The implication is that operators should make a concerted effort to record the pumping rate at the highest practical temporal resolution throughout the duration of the test.

Potential of Groundwater Reserves in Jeneponto Regency of South Sulawesi Province

The community, both individuals and groups, need water for daily and other needs. From the various types of needs, the water for drinking water is a top priority, above all other necessities.Excessive exploitation of groundwater that exceeds the ability of aquifers to provide groundwater due to competition for various interests can cause a continuous decline in groundwater level and will certainly reduce the potential for groundwater availability in the aquifer. In this research, the potential of groundwater in Jeneponto’s aquifers in several locations is examined using in situ pumping test. From the pumping test results, it is known that the potential of groundwater reserve in Jeneponto Regency is quite significant and is spread in several districts with a minimum discharge supply of 4 litres per second. However, some procedures must be taken to protect the availability of groundwater in the regency from the technical aspects for example the determination of pumping location, the depth of groundwater pumping and the maximum pumping discharge allowed, and also all steps that support groundwater recharge.

Wolfgang Beyer: A Groundwater Scientist from Dresden.

Wolfgang Beyer: A Groundwater Scientist from Dresden.

A method for determination of water-invasion-intervals in CBM wells using dewatering data

Recent advances in production data analysis (PDA) techniques have greatly assisted engineers in extracting meaningful reservoir and stimulation information from well production data. Application of these techniques to coalbed methane (CBM) reservoirs requires that the unique coal storage and transport properties should be accounted for. In the present paper, a method was developed to determine the water invasion intervals and their location along the wellbore based on the dewatering data, and the supplemental quantity of each aquifer was also calculated. The results from calculation showed that there were three aquifers supplying water to the coalseams along the wellbore. The results of pumping test verified the existence of three aquifers and proved the accuracy of the proposed method. In addition to that, it demonstrated that zonal isolation failure could significantly affect the dewatering efficiency and CBM desorption. Enhancing pump efficiency and squeezing cement were suggested to solve the problem. The method proposed in this paper can be used to analyze the location of aquifers conveniently and economically, and to calculate the amount of supplying water of each aquifer using dewatering data. It is considered to provide an effective method for the treatment and remediation of high water CBM wells.

Geochemical Modeling of Groundwater in AL Teeb Area (North East Missan Governorate)

Geochemical model is developed to simulate the geochemical reaction with flow direction of AL Teeb area NE of Missan Governorate, south of Iraq. Geochemical model under geochemical codes, NETPATH and WATEQ4F program is used to develop a groundwater Geochemical model to interpretation of geochemical reaction. According to the conceptual model of the study area, the aquifers system within the area is subdivided into three aquifers: Quaternary deposits (unconfined aquifer), Bai Hassan (semi-confined aquifer), and Mukdadiyah (confined aquifer). Results of pumping test; by applying AQTESOLV Professional version 4.50 for pumping test analysis to determine transmissivity (T), hydraulic conductivity (K.) for wells are distributed of all the studied area, The (T) value ranges from (28.17 - 613.17) m2/day and the (K)value ranges from (1.3 -12 )m/day. The groundwater quality is assessed through the analysis of the Physicochemical parameters such as pH, EC, TDS and major ions (Ca2+, Mg2+, Na+, K+, HCO−3, CI−, SO4−2), nutrients (NO3−).Two generalized flow paths were selected for the study area. These flow paths begin near the Iraq – Iran boundary to the middle of the study area from northeast to the southwest. The detailed results of the ionic strength calculations for and mineral saturation indices. All samples in the selected flow path are under saturated concerning Pco2. The concentrations of calcium, magnesium, Bicarbonate, and sulfate increase along groundwater flow paths. All waters sampled are oversaturated concerning pure stoichiometric calcite. The SI tells us about the mineral is, in fact, present and is dissolving (SI < 0), or is, in fact, precipitating (SI > 0. The primary goal of the mass balance modeling is to define the net mass of minerals dissolved or precipitated along the flow path down gradient. There are two main flow paths reaction indicate system state for different phases CALCITE, DOLOMITE, GYPSUM, ARAGONITE, DIOPSIDE, and NaCl. The flow path 1 between wells (WS-12 and WS-23) and it is representing the lower aquifer in the study area. Where model NETPATH code checked (35) models and four models are compatible with the found concentrations of the chemical elements and selected phases of this reaction. The flow path between wells (WS-4 and WS-18) and it is representing the upper aquifer in the study area, where model NETPATH code checked (15) models and Four models are compatible with the found concentrations of the chemical elements and selected phases of this interaction reaction.

A hybrid optimization approach for parameter estimation of confined and leaky confined aquifers

Abstract The main objective of this study is to propose a linked simulation–optimization approach for solving aquifer parameter estimation problems from pumping test results. In the simulation part of the proposed approach, the drawdowns at given monitoring points and times are calculated by considering the Theis and Hantush approaches for confined and leaky confined aquifers, respectively. This simulation part is then integrated to a newly proposed hybrid optimization approach, namely DE–Solver, which integrates the differential evolution (DE) algorithm and generalized reduced gradient (GRG) method of the spreadsheet Solver add-in. The performance of the proposed approach is evaluated by considering two pumping test data for confined and leaky confined aquifers. Identified results indicate that the proposed approach provides better results than those obtained by using different approaches in the literature.

A Simplified Approach to Design Jet-Grouted Bottom Sealing Barriers for Deep Excavations in Deep Aquifers

This paper presents a simplified methodology for the design of jet-grouted bottom sealing barriers (temporary water-tightness structures) for deep excavations that was undertaken in deep aquifers. The bottom sealing barriers are usually required to prevent uplift failure against the water head below. Additionally, jet-grouted bottom sealing barriers are never perfect due to the uncertainties of jet grouting columns at the site, so the design must carefully consider the analysis of seepage. For these reasons, the proposed calculation procedure focuses on two different failure mechanisms (i.e., “instability failure” and “seepage failure”) of massive bottom sealing barriers. Subsequently, the design parameters of the jet-grouted bottom sealing barriers (e.g., depth and thickness) for an excavation case were determined while using the proposed design procedure. The field pumping test results show that the water-tightness performance of bottom-sealing barriers performed at site is good, which ensures that the water level inside the excavation can reach the desired level and the groundwater drawdown outside can be minimized. The leakage flow rate of bottom-sealing barriers is lower than the designed maximum allowable seepage when the water level inside stabilizes at the final period of the pumping test.

Real-time hybrid dike breach model: simulating reservoirs of arbitrary shape and volume in laboratory tests

ABSTRACT Dikes and earthen embankments are common parts of modern infrastructure. Dike breaches resulting from extreme weather conditions and a lack of maintenance have caused significant damage to populated and agricultural areas in the past. Despite recent research findings, the effects of the parameters reservoir water volume and reservoir shape have not been properly assessed due to limitations in laboratory channel size and/or a lack of adequate test methodology. Furthermore, repeatability during the breach initiation phase has proved difficult to achieve when applying standard test methods. Therefore, a novel pump regulation method is introduced with the objective of simulating reservoirs of arbitrary size and shape during dike breach tests. This real-time, fully coupled hybrid modelling approach reduces test limitations due to limited laboratory space and considerably improves repeatability during the breach initiation phase. The pump regulation method, its limitations, test results and possible applications in the hydraulic laboratory are presented.

Assessment of shallow groundwater on the bank of the ISTN lake through lakebank filtration based on aquifer properties, pH, total dissolved solids (TDS), and microbiological analysis

A lakebank filtration assessment was carried out on the shallow groundwater surrounding the ISTN lake to evaluate of the shallow groundwater resources in the area. The objective of this research is to describe the shallow groundwater characteristics based on aquifer properties, pH, TDS and microbiological analysis. This research was conducted by making boreholes and observation holes at the bank of the ISTN area for 3 points in a single line perpendicular to the Lakebank together with 3 points in a single line perpendicular to the canalbank for doing the experiments and taking samples for pH, TDS, and microbiology analysis. Based on aquifer properties using boring and pumping test results, the aquifer layer with a thikness around 4 m show the normal storage coefficients between 0.00026 and 0.0316. From the pH, TDS, and microbiological analysis for sampling taken from boring 2.1, 2.2., and 2.3 with the distance around 10, 20, 30 m from the lake boundary were found in range of fresh water with zero patogent microbial population but the pH of some samples was lower than the pH of drinking water requirement in which that should be improved by using simple treatment before consumption.

Water services with independent providers in peri-urban Maputo: Challenges and opportunities for long-term development

Water service delivery to most residents of peri-urban areas of greater Maputo depends largely on alternative service providers, mostly in the form of small-scale independent providers (SSIPs). This paper discusses the present and long-term challenges facing SSIPs in supplying quality water of sufficient quantity in peri-urban Maputo and possible human health risks associated with the consumption of water provided by SSIPs. Extensive water sampling and analyses were conducted to evaluate the physicochemical and bacteriological quality of water provided by independent providers and the associated human health risks. Borehole pumping tests, the results of which were interpreted using the graphical method of Jacob, were used to evaluate the regional aquifer potential, the long-term impacts of its exploitation and the aquifer vulnerability to external contamination. From the results of borehole pumping tests it was concluded that the present yields are in average 33% lower than estimated safe yields and that larger than present yields therefore can be exploited. The aquifer vulnerability to external contamination (e.g. by E. coli and nitrates) is low, mainly because of low hydraulic loads and the existence of a rather thick (10 to 30 m) sandy unsaturated stratum where bacteria die-off and biological denitrification probably occurs. However, the aquifer vulnerability to sea sea-water intrusion is high. Currently, the health risks posed to consumers relying on services provided by SSIPs are small; even so, 13 out of 35 controlled boreholes had either total coliform or faecal coliform levels higher than the WHO standard. In the long run SSIPs may face more serious water quality problems due either to over-exploitation of the aquifer system or increased hydraulic loads resulting from increased population density.

Estimation of hydraulic transmissivity from MRS by varying the porosity exponent in detrital aquifers of the Iberian Peninsula

ABSTRACTTo this date, estimation of hydraulic transmissivity with magnetic resonance sounding (MRS) requires transmissivity values from pumping tests in nearby wells in order to determine a calibration constant from the relationship between both types of data. The use of this technique is limited due to the fact that reported values of this calibration constant are highly variable, even within the same type of aquifer. In order to minimize this shortcoming, a new methodology, which has been developed and presented here, is used to estimate the transmissivity of detrital aquifers with heterogeneous behaviour based only on the results obtained by MRS. The exponents applied to decay time and free porosity used in the expression to compute MRS transmissivity have conventionally been fixed values. In contrast, the work presented here aims to improve the applicability of this technique using a variable exponent for free porosity in each type of aquifer, obtained only from MRS results. In order to achieve this goal, previously published MRS data from four detrital aquifers in the Iberian Peninsula have been used and a relationship between the porosity exponent and a function of decay times and free porosities has been developed. This approach eliminates the need to drill and perform pumping tests in additional boreholes, which has cost and time implications, once the correct expression is determined for a given type of aquifer. The range of values thus obtained for the porosity exponent is similar to that reported in the literature. The deviation of the results obtained with this methodology regarding the results of pumping test is similar to the deviation with conventional process. This suggests that the proposed methodology is appropriate for the aquifers considered, and the approach may be expanded to study other types of aquifers. The drawbacks of the proposal related to the conventional equivalence are explored.

HYDRAULIC PROPERTIES OF THE BAI-HASSAN AQUIFER IN TUZ-KHURMATU, SALAHADDIN, IRAQ

The studied area is located within Salahadden Governorate between latitudes 34° 50' 00" – 34° 55' 00" and longitudes 44° 33' 00" – 44° 40' 00" south of Kirkuk city of about 70 Km with an approximate area of about 124 Km2. The important geological formations in the area consist of Tertiary deposits Al-Fatha, Injana, Muqdadiya and Bai-Hassan formations as well as recent Quaternary deposits which cover the study area. Depending on the climatic data recorded in Tuz-Khurmatu station for the period 1991 – 2014, found that the summation of rainfall is 274.21 mm, average of temperature 22.8 °C, relative humidity 46.93%, wind speed 1.83 m/sec, sunshine 8.28 h/day and the total of evaporation is 2376.2 mm. The common climate in the area is humid to moist. The studied area is located within Al-Adhaim basin whose area is about 12000 Km2. The productive hydrogeological unit in the studied area is Bai-Hassan Formation. The general direction of groundwater flow is from northeast towards the southwest. By using Theis recovery 1935 and Cooper-Jacob 1946 methods pumping test results which performed in seven wells that penetrate Bai-Hassan Formation partially without observation wells indicated a transmissivity values range between 95.47 – 335.72 and the median value of 176.11 m2/day and hydraulic conductivity values between 2.11 – 4.47 m/day and the median value of 3.06 m/day. These reflect that the hydraulic properties values of Bai-Hassan aquifer in the study area are heterogeneous and variant, as a result of heterogeneity of Bai-Hassan aquifer due to variations in lithology and porosity. Specific capacity for these wells is measured and found varying between 172.8 – 432 m²/d. It shows an inverse relationship between the specific capacity and drawdown in the wells.

Pre-screening of hydraulic fluids for vane pumps: An alternative to Vickers vane pump tests

The tribological behaviour of hydraulic fluids is mainly evaluated by standardized Vickers vane pump tests, according to ASTM D7043, DIN 51389 or ISO 20763. These tests provide the closest possible representation of actual working conditions, but require many hours of testing and large quantities of hydraulic fluids per experiment, while the frictional behaviour of the tribosystem is not measured. Because of the long testing time, oil quantity and cost, it is impractical to perform multiple tests and this makes the method unsuitable for development purposes. In this work, a new methodology is proposed that allows for a fast and efficient pre-screening and ranking of hydraulic fluids that correlates well with the Vickers vane pump test. To validate the methodology, five different hydraulic fluids are tested and compared to ISO 20763 Vickers vane pump test results. The aim is to achieve similar wear mechanisms and ranking of the anti-wear properties of hydraulic fluids. The future goal is to propose a standardized method that will aid in the development of hydraulic fluids and will complement existing standardized tests.

A method for the estimation of dual transmissivities from slug tests

Aquifer homogeneity is usually assumed when interpreting the results of pumping and slug tests, although aquifers are essentially heterogeneous. The aim of this study is to present a method of determining the transmissivities of dual-permeability water-bearing formations based on slug tests such as the pressure-induced permeability test. A bi-exponential rate-of-rise curve is typically observed during many of these tests conducted in heterogeneous formations. The work involved analyzing curves deviating from the exponential rise recorded at the Belchatow Lignite Mine in central Poland, where a significant number of permeability tests have been conducted. In most cases, bi-exponential movement was observed in piezometers with a screen installed in layered sediments, each with a different hydraulic conductivity, or in fissured rock. The possibility to identify the flow properties of these geological formations was analyzed. For each piezometer installed in such formations, a set of two transmissivity values was calculated piecewise based on the interpretation algorithm of the pressure-induced permeability test—one value for the first (steeper) part of the obtained rate-of-rise curve, and a second value for the latter part of the curve. The results of transmissivity estimation for each piezometer are shown. The discussion presents the limitations of the interpretational method and suggests future modeling plans.

A method of the determination of hydrogeological parameters of the aquifers on the results of the experimental constant-rate pumping tests

On the basis of the approximate solution of the problem of groundwater filtration during the experimental constant-rate pumping tests of the pressure aquifers, a method for the processing and interpreting the results of this operation has been developed in order to determine the filtration-volumetric parameters of the horizon. The method is combined as much as possible with the currently widely used graphic-analytical method. The proposed method has been shown to have substantially less restrictions on the duration of the experimental perturbation (pumping) than the currently used graphic-analytical one.

Analyze the Well Losses and Aquifer Losses on the Pumping Test Results

The analysis of step-drawdown test data enables to determine the total drawdown in the pumped well, to evaluate the performance of the well. Therefore, the main objective of this paper is to introduce a method (Jacob, 1947) to calculate the linear, and non-linear components of the well loss. The proposed method applied on a well tapped in confined aquifer, which located in Basrma sub-district area, related to Erbil province, the test conducted in the absence of the observation well, so the storage coefficient in this case is not reliable. the advantage of this method is that, it is valid for any stepped pumping. The main conclusion of this research is that, the method can be successful used in the practical application having the similar condition, on the other hand, it can be used for estimating the efficiency of the well.

Application of Chemical Dynamics Method in Solving Hydro-Geological Parameters

With the increasing of coal mining depth, the coal seam floor is threatened more and more seriously with the limestone aquifer of Taiyuan Formation. In order to make the coal seam floor water inrush accident to be effectively prevented, it is very important to ascertain the hydro-geological condition of the research area and adequately gain hydro-geological parameters. Based on the theory of chemical dynamics, the chemical dynamical equation of the mineral was obtained. The chemical dynamical equation of the mineral and the Darcy’s Law were combined to derive the expression of permeability coefficient and transmissibility coefficient that was indicated by hydro-chemistry index. Based on the data of water quality analysis in the research area, the hydro-geology parameter of the aquifer of Taiyuan Formation was calculated. And it was compared with what the hydro-geology parameter was determined by the data of pumping test. The results show that the permeability coefficient (K) of the research area is 1.7512 m/d, and transmissibility coefficient (T) is 42.0282 m2/d. The calculated results of chemical dynamics and pumping test results are little different between them. And it has certain practical significance in the mine water control. It provides an effective method for obtaining hydro-geological parameters.

The properties of concrete mixes, pumped over long distances

The influence of technological factors, chemical and mineral admixtures on pumping and thixotropic properties of concrete mixtures was studied. The causes of the loss of pressure when pumping concrete mixtures through channels of a complex section are established. Existing methods for calculating pressure loss during pumping of concrete mixtures are considered. Some results of pumping tests of modern concrete mixtures are given. It is shown that the use of powdered concrete with high mobility for pumping over long distances during the filling of long-span metal or bridge structures, concreting in tunnels where injection pressure is limited, can be the only solution in the implementation of these tasks.