دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: the motion a bit makes when it does not rotate around its centre but instead drills with a spiral motion. It usually occurs to a bit drilling in a soft or medium soft formation when the driller does not apply enough weight or does not rotate the bit fast enough. A whirling bit drills an overgauge hole (a hole larger than the diameter of the bit) and causes the bit to wear abnormally.

n: a hole whose diameter is larger than the diameter of the bit used to drill it. An overgauge hole can occur when a bit is not properly stabilised or does not have enough weight put on it.

n: the well its diameter exceeds the diameter of bit.

n: see overgauge hole.