Open AccessDATA PROCESSING TECHNIQUES FOR PUMPING TESTS WITH MULTIPLE PARTIALLY PENETRATING WELLS
Author(s) -
М.В. Лехов
Publication year - 2018
Publication title -
inženernaâ geologiâ
Language(s) - English
Resource type - Journals
eISSN - 2587-8247
pISSN - 1993-5056
DOI - 10.25296/1993-5056-2018-13-4-5-98-107
Subject(s) - logarithm , tracing , aquifer , computer science , aquifer test , plot (graphics) , algorithm , geology , mathematics , geotechnical engineering , groundwater , mathematical analysis , statistics , groundwater recharge , operating system
In addition to correct planning, pumping tests with partial penetrating wells, requires methods of processing and calculating parameters that are understandable not only to hydrogeologists, but also to geologists of related specialties. The data processing procedure should be brought to simple plotting and formulas. This requires an understanding of the validity and limitations in the use of the original expressions. Data analysis should begin with a meaningful diagnosis of pumping modes on experimental plots. Developed in the last decades, analytical solutions are applicable to homogeneous aquifers and include complex mathematical functions with complex arguments. Their use requires software. Without justification of the applicability of the chosen model, the mechanical computer "calculation" of pumping has serious drawbacks. The article presents methods for calculating hydraulic parameters from experimental pumping data that can be applied to nonhomogeneous conditions and take into account both degree of partial penetration and near-well destruction. The techniques use the known methods of a straight line on the graphs of combined and area tracing drawdown in semi-logarithmic coordinates, developed for fully penetrating wells. To do this, the well-known formulas introduce a correction ζΣ for degree of partial penetration, anisotropy, inertia of the wells, and other factors. The coordinate of the observation well r is replaced by the rated value rp = r•exp( ζΣ/2). It is impossible to calculate ζΣ except for the case of a homogeneous aquifer. Therefore, it is necessary to determine rp by selection, seeking to combine the experimental well curves on the combined tracking plot. The application of the method requires a realistic view of the accuracy of the field test in general and the procedure used in particular. The article is illustrated by plots and calculations of real field tests, the presentation is accompanied by an analysis of the causes of defectiveness of pumping data.