دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: a hollow cylindrical device installed around the swivels rotating stem that absorbs the stems rotation and helps form an oil seal between the stem and the oil-bath reservoirs inside the swivel.

n: A kind of liner that can decrease the wear and tear ,which be fixed on the out surface of the drilling string.