News Update on Aquifer Research: Jan – 2020

Theory of Aquifer Tests

The development of water supplies from wells was placed on a rational basis with Darcy’s development of the law governing the movement of fluids through sands and with Dupuit’s application of that law to the matter of radial flow toward a pumped well. As field experience increased, confidence within the applicability of quantitative methods was gained and interest in developing solutions for more complex hydrologic problems was stimulated. a crucial milestone was Theis’ development in 1935 of an answer for the nonsteady flow of spring water , which enabled hydrologists for the primary time to predict future changes in ground-water levels resulting from pumping or recharging of wells. within the quarter century since, quantitative ground-water hydrology has been enlarging so rapidly on discourage the preparation of comprehensive textbooks. [1]

Aquifer disposal of CO2: Hydrodynamic and mineral trapping

A general approach to evaluating sedimentary basins for CO2 disposal is presented during this paper. The approach is exemplified for the case of the Alberta Basin in western Canada where a wealth of geological and hydrogeological data from quite 150,000 wells drilled by the refining industry allows for a correct estimate of the basin potential for long-term storage of CO2 captured from fossil-fuelled power plants. Geochemical and hydrogeological analyses of CO2 interaction with the aquifer water and rocks, and of CO2 transport in miscible and immiscible phase by the natural flow of aquifer water indicate that, besides stratigraphic trapping, two additional mechanisms are available for the capture and long-term retention of CO2 within the subsurface. [2]

Non‐steady radial flow in an infinite leaky aquifer

The non‐steady drawdown distribution near a well discharging from an infinite leaky aquifer is presented. Variation of drawdown with time and distance caused by a well of constant discharge in confined sand of uniform thickness and uniform permeability is obtained. The discharge is supplied by the reduction of storage through expansion of the water and therefore the concomitant compression of the sand, and also by leakage through the confining bed. The leakage is assumed to be at a rate proportional to the drawdown at any point. Storage of water within the confining bed is neglected. Two sorts of the answer are developed. One is suitable for computation for giant values of your time and therefore the other suitable for little values of your time . This solution is compared with earlier solutions for slightly different boundary conditions. [3]

Quantitative hydro-geophysical analysis of a complex structural karst aquifer in Eastern Saudi Arabia

The Umm er Radhuma (UER) Formation may be a major karst aquifer in Saudi Arabia . This study investigated the hydraulic and petrophysical characteristics of the folded UER carbonate aquifer using integrated hydrological and geophysical logging datasets to know its complex hydraulic setting also as detect possible water flow. Petrophysical analysis showed that the UER aquifer has three zones with different lithologic and hydraulic properties. The upper zone attains the simplest properties with average values of 20%, >100 mD, 3.30 × 10−5–1.34 × 10−3 m/s, and 1.49 × 10−3–6.04 × 10−2 m2/s, with reference to effective porosity, permeability, hydraulic conductivity and transmissivity. [4]

Assessment of Aquifer Pollution Vulnerability Index at Oke–Ila, South-western Nigeria Using Vertical Electrical Soundings

The study was undertaken with the aim of estimating vulnerability index of shallow aquifer within weathered crystalline regolith that overlies the basement complex rocks of Oke-lla, Osun State, South-western Nigeria. Twenty five vertical electrical soundings adopting Schlumberger configuration were wont to investigate the subsurface lithology in a neighborhood covering 48 km2. The result revealed four distinct geologic layers which contains top soil, weathered layer (clayey/sandy saprolite), sand, and fractured/fresh basement rocks. The saprolite, characterized by resistivity within the range of 44 and 471 Ωm with thickness varying from 7 to 16 m, acts as shallow aquifer storing infiltration water. The thickness of the layers above the aquifer, as obtained from quantitative interpretation of resistivity sounding data and estimates of hydraulic conductivities, were wont to quantify vulnerability indices. [5]

Reference

[1] Ferris, J.G., Knowles, D.B., Brown, R.H. and Stallman, R.W., 1962. Theory of aquifer tests (pp. 69-174). Denver, Colorado: US Geological Survey. (Web Link)

[2] Bachu, S., Gunter, W.D. and Perkins, E.H., 1994. Aquifer disposal of CO2: hydrodynamic and mineral trapping. Energy Conversion and management, 35(4), (Web Link)

[3] Hantush, M.S. and Jacob, C.E., 1955. Non‐steady radial flow in an infinite leaky aquifer. Eos, Transactions American Geophysical Union, 36(1), (Web Link)

[4] Quantitative hydro-geophysical analysis of a complex structural karst aquifer in Eastern Saudi Arabia
Mohamed El Alfy, Aref Lashin, Turki Faraj, Abed Alataway, Qassem Tarawneh & Abdelaziz Al-Bassam
Scientific Reports volume 9, (Web Link)

[5] Aweto, K. E. and Ohwoghere–Asuma, O. (2018) “Assessment of Aquifer Pollution Vulnerability Index at Oke–Ila, South-western Nigeria Using Vertical Electrical Soundings”, Journal of Geography, Environment and Earth Science International, 16(2), (Web Link)

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