Heavy Weight Drill Pipe : Drill pipe fabricated with thick wall tube. Frequently used in place of drill collars to apply weight on the drill bit. Handles like normal drill stem in drilling operations. (Bul D20).
The Mudblogger (Oilfield, Energy and Related Photographs), Oil Field Glossary, TX, USA 2014. http://mudblogger.com/oilfield-glossary/, (Oil - Amer) {777}