A Statistical Evaluation of Formation Disturbance Produced by Well-Casing Installation Methods

摘要

Water-resources investigations concerned with contaminant transport through aquifers comprised of very loose, unconsolidated sediments have shown that small-scale variations in aquifer characteristics can significantly affect solute transport and dispersion. Various sampling and borehole-logging techniques have been integrated into these studies to detect and measure detailed formation changes through casing or well screen along the length of the borehole. Commonly, measurement accuracy and resolution have been limited by a borehole environment consisting of an annulus of disturbed sediments produced by the casinginstallation method.