(adj.) Well Completions. Pertaining to equipment, facilities or systems located in the wellbore or production train before the surface choke or Christmas tree. Ant: downstream. See: Christmas tree
Schlumberger Ltd. (The World's Leading Supplier Of Technology, Integrated Project Management And Information Solutions to Customers Working in The Oil and Gas Industry Worldwide), Schlumberger Oilfield Glossary Cedex, France 2014. http://www.glossary.oilfield.slb.com/en/Terms/sym/ a.aspx, (Ergo - Brit) {766}