Downhole safety system for use while servicing wells

摘要

A safety valve which prevents undesired fluid flow while conducting hydraulic workover or snubbing operations on a well. The safety valve includes three separate valve portions for blocking fluid flow. A poppet valve can be opened and closed from the well surface. Elastomeric sealing elements form a fluid barrier with the exterior of the work string. The work string itself opens and closes a flapper valve. The poppet valve allows fluid flow to bypass the elastomeric sealing elements.