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Altering Dissolved Oxygen to Determine Flow Conditions in Fractured Bedrock Wells
Author(s) -
Chlebica Dariusz W.,
Robbins Gary A.
Publication year - 2013
Publication title -
groundwater monitoring and remediation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.677
H-Index - 47
eISSN - 1745-6592
pISSN - 1069-3629
DOI - 10.1111/gwmr.12019
Subject(s) - borehole , bedrock , geology , slug test , tracer , flow (mathematics) , petroleum engineering , flow measurement , hydraulic fracturing , geotechnical engineering , metre , hydrology (agriculture) , groundwater , geomorphology , aquifer , mechanics , physics , nuclear physics , astronomy
A new approach to locate transmissive fractures and decipher vertical borehole flow conditions in fractured crystalline bedrock wells is presented, which uses dissolved oxygen ( DO ) as a benign tracer. The method was tested in two fractured crystalline bedrock wells previously characterized by televiewer and flow meter logging under both ambient and stressed (slug test) conditions. The method entailed elevating wellbore DO concentrations by circulating water through showerheads or injection of compressed air. The DO dilution was used to locate inflowing fractures. Changes in the DO concentration with time were used to ascertain flow within the borehole and to locate outflowing fractures and stagnant zones. Flow rates were also estimated. Fractures detected by the method corresponded to those observed by televiewer logging and for the most part were comparable to flow meter results. Given the effectiveness, time‐efficiency and low cost, the method is a promising alternative to other methods currently in use to characterize transmissive fractures in wells.