ok it is important to note the time of the pip. under normal conditions, the chick would pip into the air cell (internal pip) but this did not happen with your chick. the chick usually takes another 12 hours before it externally pips.
after externally pipping, it can be another 12 hours until it starts to zip. so at a MINIMUM I would give it 24 hours to sit in the shell and absorb. Also during this absorb time, turn the pip upward so any liquid still in the egg doesn't drip down into the nostrils & beak.
it is most likely that it won't be able to zip due to malposition since it pipped the wrong end. it is possible though!!! they have to use their feet to spin around in the shell, so it completely depends on how they are positioned in the egg. I had a chick who pipped the bottom of the shell zip itself completely before.
just keep the membrane moistened and check on it often. don't chip away any more shell for at least 24 hours or it could rip a vein and cause bleeding; the veins are still active at this time.
I like to use neosporin or anti-biotic ointment (without pain reliever) to keep it moistened, it soaks into the membrane and keeps it from sticking to the chick, longer than water will.
read more about intervention:
https://www.backyardchickens.com/t/9316/intervention-helping-your-chicks-hatch
make sure to give it 24 hours first!
