The IADC Lexicon is an oil and gas dictionary of upstream-related terms, which, unlike conventional glossaries, are official definitions drawn from legislation, regulation and regulatory guidance, standards (global, national and regional), IADC guidelines, and Well Control Institute. Terms often have multiple definitions from different sources.
This month’s featured term is:
A measure of the amount of change in the inclination and/or direction of a borehole, usually expressed in degrees per 100 feet of course length.
Source: API RP 7G, Recommended Practice for Drill Stem Design and Operating Limits, Upstream Segment, Sixteenth Edition, August 1998 (Addendum 2: September 2009).