How to prevent sticking and get a nice searing on scallops
Most likely, you're not heating your pan enough before placing the scallops in.  Without knowing your exact method it's hard to say what's going wrong, but 1-2 tbsp of oil should be enough for a normal amount of scallops.  

To learn about properly heating your pan, I recommend this link:

http://www.houseboateats.com/2009/12/on-properly-heating-your-pan.html