دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: a short length of pipe (a nipple) installed on top of the blowout preventer. The top end of the nipple is flared, or belled, to guide drill tools into the hole and usually has side connections for the fill line and mud return line.

a funnel shaped pipe at the top of the casing that guides tool string entry and may have a side port for fluid pumping.