دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: a tool that, when lowered into the wellbore, makes a photographic record of the angle and drift of the wellbore;that is, it records the number of degrees the hole is off vertical and the direction in which it is off vertical. Several types of instrument are available;some are capable of photographing only a single record - single-shot survey instrumentswhereas others are capable of making several records in one run - multishot survey instruments.