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Friction loss correction in flowing well discharge tests
Author(s) -
Wendland Edson
Publication year - 2008
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1029/2007wr006365
Subject(s) - wellhead , aquifer , casing , head (geology) , artesian aquifer , mechanics , radius , geotechnical engineering , geology , environmental science , petroleum engineering , groundwater , physics , computer science , geomorphology , computer security
Artesian confined aquifers do not need pumping energy, and water from the aquifer flows naturally at the wellhead. This study proposes correcting the method for analyzing flowing well tests presented by Jacob and Lohman (1952) by considering the head losses due to friction in the well casing. The application of the proposed correction allowed the determination of a transmissivity ( T = 411 m 2 /d) and storage coefficient ( S = 3 × 10 −4 ) which appear to be representative for the confined Guarani Aquifer in the study area. Ignoring the correction due to head losses in the well casing, the error in transmissivity evaluation is about 18%. For the storage coefficient the error is of 5 orders of magnitude, resulting in physically unacceptable value. The effect of the proposed correction on the calculated radius of the cone of depression and corresponding well interference is also discussed.