A cap for sealing a wellhead assembly of a subterranean well and suspending well assets (e.g., tubing, rods, etc.) therefrom within the well to facilitate production at the well after a period of abandonment. For instance, a decompletion process may be performed on a particular well to be temporarily abandoned which may include disconnecting a pumpjack (e.g., horsehead unit, pumping unit, etc.) from a wellhead of the well, breaking (e.g., disconnecting) the wellhead at the first flange (e.g., closest to ground level) to leave a casing head of the wellhead exposed, and/or the like. Ends of a tubing string and a rod string disposed within the subterranean well may be respectively secured within portions of the disclosed cap. The cap may then be placed and secured over the exposed casing head to limit entry of foreign objects and debris into the well.