Implications of Using Approximate Expressions for Well Function
This article has a reply.
VIEW THE REPLYPublication: Journal of Irrigation and Drainage Engineering
Volume 121, Issue 6
Abstract
The computation of the well function is required in the analysis of pump test data for leaky or confined aquifers. Approximate expressions have recently been proposed to compute the well function over the whole range of the argument values. These proposed expressions are more computationally intensive and less accurate than some standard exponential integral approximations. Analysis of a synthetic data set using slope-matching technique shows that use of these recent expressions results in severe overprediction of the storage coefficient, especially for aquifers with low storage coefficient or high transmissivity.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
Abramowitz, M., and Stegun, I. A. (1970). Handbook of mathematical functions, National Bureau of Standards, Washington, D.C.
2.
Allen, E. E.(1954). “Analytical approximations.”Math. Tables Aids Comp., 8(48), 240–241.
3.
Bourdet, D., Ayoub, J. A., and Pirard, Y. M.(1989). “Use of pressure derivative in well-test interpretation.”SPE Formation Evaluation, 4(2), 293–302.
4.
Chow, V. T.(1952). “On the determination of transmissivity and storage coefficient from pumping test data.”Trans., Am. Geophys. Union, 33(3), 397–404.
5.
El-Khatib, N. A. F.(1987). “A new approach to interference test analysis.”SPE Formation Evaluation, 2(4), 609–610.
6.
Hastings, C. Jr. (1955). Approximations for digital computers . Princeton University Press, Princeton, N.J.
7.
Sen, Z.(1986). “Determination of aquifer parameters by the slope-matching method.”Ground Water, 24(2), 217–223.
8.
Srivastava, R., and Guzman-Guzman, A.(1994). “Analysis of slope-matching methods for aquifer parameter determination.”Ground Water, 32(4), 570–575.
9.
Swamee, P. K., and Ojha, C. S. P.(1990a). “Pump test analysis of confined aquifer.”J. Irrig. and Drain. Engrg., ASCE, 116(1), 99–106.
10.
Swamee, P. K., and Ojha, C. S. P.(1990b). “Pump test analysis of leaky aquifer.”J. Irrig. and Drain. Engrg., ASCE, 116(5), 645–655.
11.
Theis, C. V. (1935). “The relation between the lowering of the piezometric surface and the rate and duration of discharge of a well using ground-water storage.”Trans., Am. Geophys. Union, 16(II), 519–524.
12.
Tiab, D., and Kumar, A. (1980). “Application of the function to interference analysis.”J. Pet. Technol., 32(8), 1465–1470.
Information & Authors
Information
Published In
Journal of Irrigation and Drainage Engineering
Volume 121 • Issue 6 • November 1995
Pages: 459 - 462
Copyright
Copyright © 1995 American Society of Civil Engineers.
History
Published online: Nov 1, 1995
Published in print: Nov 1995
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.