Petrophysics
Petrophysics
Introduction:
The following diagram shows core marking procedures found in an old Exxon/Esso Wellsite manual. I do not know the authors names. Hope they are useful to someone.
It appears that the above suggested core marking method has not been universally adopted. I received the following e-mail from Duncan Barr who is an expert with many years of experience in all aspects of core processing and analysis.
"When I came across the Core Marking Guide, I thought you might be interested in my experiences in this subject. In the diagram, arrows point up the core, the red line is on the left, and the black line is on the right. If I remember correctly, I think this might be the old Exxon standard. Unfortunately, you rarely see cores marked like this unless they're from an Exxon or ExxonMobil-affiliated company. In Australia, the standard (non-Exxon) method is generally to have arrows pointing downwards, and line colours that are usually red on the right, and blue or black on the left. In SE Asia and the Middle East, most of the cores I've seen have a similar colour convention - red on the right, blue or black on the left - but arrows pointing upwards. In North Africa (well, Libya at least), it seems to be a question of pot-luck, with just about any variation on the above - with or without coloured lines, arrows pointing upwards, downwards, no arrows at all, and sometimes no markings at all. In some older cores, you might see the entire spectrum of markings, as successive generations of geologists have tried to figure out which bits are the wrong way up. I've even seen arrows on some shorter segments pointing sideways! "
The United States Department of Energy Los Alomos Laboratory Environmental Restoration Project has published guidelines for marking and boxing core that is available at;
Briefly, the guidelines recommend parallel orientation stripes with red on the right and a blue on the left. No arrows or T/B labels are included in the recommendations.
The Integrated Ocean Drilling Program (IODP) has produced a core processing guide -cookbook- that is available on the Internet at;
The IODP procedures do not specify colours for orientation stripes, but do specify arrows pointing to the top of the core. This project also has very rigorous procedures for labeling of every core fragment.