The calculated distance (air line) between Al Qaryatayn and Deir ez-Zor is approximately 181 miles respectively 292 kilometers.
By car or train, the actual journey to Deir ez-Zor is certainly longer, as only the direct route (as the crow flies) between Al Qaryatayn and Deir ez-Zor has been calculated here.
Air line (approximately)
292 kilometers
158 nautical miles