Marine Drilling Riser : A tubular conduit serving as an extension of the well bore from the equipment on the wellhead at the seafloor to a floating drilling rig. (RP 2R)
The Mudblogger (Oilfield, Energy and Related Photographs), Oil Field Glossary, TX, USA 2014. http://mudblogger.com/oilfield-glossary/, (Oil - Amer) {777}