Oriented core; its use, error, and uncertainty
Oriented core; its use, error, and uncertainty
AAPG Bulletin (April 1987) 71 (4): 357-367
Error analysis of oriented-core data indicates that: (1) the error in the coring and surveying procedure is + or - 5 degrees ; (2) the error inherent to the mechanical goniometer is + or - 2 3/4 degrees ; (3) the reproducibility error in using the goniometer is + or - 2 degrees for one analyst and + or - 4 degrees for multiple analysts; and (4) the uncertainty in interpolating and manipulating sets of orientation data may be quite large. Overall error in oriented core procedures should be considered + or - 11 degrees . A simple set of guidelines can be used to determine the most accurately oriented zones within the core. The guidelines are based on the physical character of the core, orientation scribes, and patterns displayed by plotting the azimuth of the orientation groove versus depth. Approximately 26% of oriented core analyzed fits the guidelines of most accurately oriented core.