Artesian wells are under positive pressure and do not need vent. If it has enough pressure to bring water to the surface and dump say 1 GPM directly on the ground, it will do less GPM in a pipe with air pushing back at it, and more GPM in a pipe using a siphon to reduce the pressure at the well head.
Looks like someone wrapped that first elbow trying to prevent a suction leak, They were on the right track, but there are several more places to lose the vacuum. I would replace all threaded fittings and put an AAR (Auto Air Relief) at the highest point. You can draw more water from the well if that 1.5 PSI positive pressure down at your tank is changed to a 1.5 PSI suction. Sealing any air leaks and releasing the air that accumulates in the high spot will let gravity (siphon) work for you instead of against you.
Otherwise just put a tee at the top with the high side open to let out enough air that some water can flow down the pipe the same way it would an open trough.