The short answer is in a modern oil/gas field if storage were full or export pipelines were not moving product the wells would most likely shut in on their own or could be with a few keystrokes. A planned shut in of a well could be done at a controlled rate to avoid a hard shut in that might cause formation damage .
Wells in older fields may not be so equipped so they'd have to be manually shut in but it can still be done via site visits provided of course the valves and equipment have been maintained and there's not something like a fire restricting access .
If the trees (surface valves) and piping are damaged and you have wells flowing freely to atmosphere than that's a completely different animal that is going to require well control intervention. If that's the case on multiple wells then that suggests sabotage of some type like bombing. I can't think of a reason the Iranians would want their wells flowing to atmosphere uncontrolled . They would just be depleting their own reserves and possible causing downhole damage that is very expensive to stop and later reestablish.