The calculated distance (air line) between Ḩalfāyā and As Safīrah is approximately 71 miles respectively 114 kilometers.
By car or train, the actual journey to As Safīrah is certainly longer, as only the direct route (as the crow flies) between Ḩalfāyā and As Safīrah has been calculated here.
Air line (approximately)
114 kilometers
62 nautical miles