a. Correction made when drilling running ground, alluvial gravels, and
sands. The volume actually extracted over a measured depth is compared
with that which would be obtained over the true drill pipe area and
distance, any discrepancy being due to inrush of sands or forcing out of
sand by the pumping action during drilling. Pryor, 3
b. The assumed cross-sectional area of a length of borehole when
estimating the in situ volume of a core sample. Also called pipe constant.
Dictionary of Mining, Mineral, and Related Terms