Discussion on ‘Measurement of total core recovery; dealing with core loss and gain’ by S. Valentine & D. Norbury Quarterly Journal of Engineering Geology and Hydrogeology , 44, 397–403

Abstract

In drawing attention to the issue of ‘core gain’ the Authors have drawn attention to a problem that troubles many engineers when they encounter it, and no doubt, with the lack of formal consideration in the technical literature over the years, there have probably been any number of solutions attempted by logging engineers with, no doubt, varying degrees of success. The Authors’ solution (following the current practice as outlined in BS 5930 (BSI 2010), however, is at odds with the way I would wish to have us deal with this issue in one important aspect. It is stated, following the current guidance, that although the driller’s core run markers should not be moved, the core recoveries (TCR/SCR and RQD) should be …