Abstract: A convertible rotary seal has a housing for receiving a polish rod. A mandrel is rotatably mounted in the seal housing and surrounds the polish rod. A wear sleeve surrounding the mandrel engages a primary seal. A secondary seal engages the mandrel and polish rod and rotates therewith but may be converted for use as a static seal if necessary. A locking mechanism selectively secures the mandrel in a stationary orientation with respect to the seal housing. Fluid that leaks past the primary seal will be detectible through an external orifice. If a leak in the primary seal is detected via the external port, then the mandrel may be secured in a stationary orientation with respect to the housing and the secondary seal may be reconfigured to operate as a stationary seal until such time as the rotary sealing unit can be overhauled.

Abstract: A tubular mandrel is provided as a sleeve around the portion of the rod string polish rod extending through the stuffing box housing. The mandrel is coupled to the polish rod so that they rotate together. Bearings stabilize the mandrel within the housing. Stationary rotary seal means are provided in the housing to seal against the now-stabilized mandrel. Leakage and seal wear are improved when compared with the prior art approach of using compressed packing in direct contact with the polish rod to provide the rotary seal.