Swab Valve 1 : (n.) Well Workover and Intervention, Well Completions. The topmost valve on a Christmas tree that provides vertical access to the wellbore. 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}