How can I stop leaking oil from hole in copper pipe?

Not a lot you can do being oil no solvent sealer will stick and you can't solder it or you'll end up with a bigger fire than you wanted.
Solution as I see it:
materials 1 straight connector 1 sliding/through connector ie has no pipe stop so it can be slid up the new/old pipe then back across the joint. Length of new pipe, Pipe cutter.
Turn off the oil.
Cut out a length of old pipe cut the new to fit leaving about 1/2" gap between the pipes.
Fit straight connector to the new pipe then slide on the through sliding connecter either onto the new or the old.
Fit the straight connector end to the existing pipe then slide over the remaining joint the sliding connector set half and half across the joint. tighten joints. Clear up then turn oil flow back on.
Remember nothing will stick when oil is present.

B
June 2011