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
cooking.stackexchange.com/users/1236/stephennmcdonald
Most likely, your pan is not hot enough before you put the scallops in.
The pan should be hot enough for a drop of water to bounce around on the pan instead of just evaporating.
There have been other similar questions:
How do I prevent food from sticking to a standard (non-coated) pan?
cooking.stackexchange.com/users/2047/Bob
My first advice is to use a bit more oil, maybe.
I recently did scallops with a recipe from Thomas Keller, and his recipe calls for quite a bit of oil--probably 3 tbs or more (don't remember precisely, but it was way more than I would have put on my own).
This was also my most successful pan-seared scallop batch to date, so I think he's onto something.
And to my surprise, they were not at all greasy when served.
You will need your oil to be quite hot too, as you want to be able to caramelize the scallops on the outside fairly quickly without overcooking the inside.
Another thing is to leave the scallops alone after you first place them, and turn them only once.
When the proteins are properly caramelized, the scallops will release from the pan much more easily.
Just place them, leave them alone until that side is nicely browned, turn them over, brown and serve.
cooking.stackexchange.com/users/3348/bikeboy389
Like the other comments mentioned you need to make sure that the oil is very hot before you add the scallops.
Also, for a very nice color take a small amount of butter, about half a teaspoon, and add it to the oil.
This is might go against your intuition, however, it is the technique used by most high end French restaurants to sear Scollaps, Veal, Ris de Veau, and other light colored meats.
cooking.stackexchange.com/users/4039/Adam S
Dont use s nonstick pan-
a pan that is hot enough to get a good sear is also hot enough to burn the nonstick coating- which is very bad for you (the fumes also kills birds).
Nonstick pans also tend to be aluminum and thin, they don't hold enough heat-
the pan cools down
and you don't get a good sear.
Use cast iron or carbon steel pans if you can, they're the best for searing.
Get it very hot - water should sizzle vigorously when it hits the pan. Use more oil than you think you need.
A 1-2 mm layer will get in between the cracks of the scallop and allow for better heat transfer.
Use a oil with a high smoke point, not olive oil.
Grape seed oil works great and is neutral.
Corn oil is cheaper, so is canola.
Make sure theyre dry when they go in.
Pat them on paper towels, then season.
Don't use frozen scallops, buy dry scallops.
frozen scallops give up juice when they hit the hot pan.
Plus they are usually soaked in a solution to make them heavier.
You can tell if they were frozen because they're be sitting in a pool of milky liquid and will likely be
white/milk colored.
Dry scallops are pink, light orange or cream colored.
If you use butter, add it when you flip.
Otherwise the water cools the pan too early.
You can baste the scallop with a spoon, but keep the butter frothing by turning up the heat.
Don't mess with it, sear it.
Let it sit.
Flip once.
Keep them apart otherwise
they steam.
cooking.stackexchange.com/users/4179/Chef
Its normal for scallops to stick to a non-stick surface sautee pan.
Let them sit until they come loose from the pan.
It may take a few minutes but when they do thei will be browned perfectly.
Turn and cook another 2 min.
on the other side and spoon melted butter over them during this time.
YUMMM!
cooking.stackexchange.com/users/17153/bweatherell
When I am searing scallops, they often stick in the pan and most of the time, they are very hard to turn.  I use only a little oil 1-2 tablespoons.  Am I not using enough?
How to prevent sticking and get a nice searing on scallops
cooking.stackexchange.com
<frying><scallops><frying-pan>
cooking.stackexchange.com/questions/11582
cooking.stackexchange.com/users/4571/Noah
Use dried scallops rather than frozen, and make sure that the pan and oil are hot enough before adding them. Try using more oil and use an oil with a high smoke point. Make sure the scallops are defrosted and fully dry. Use a very hot pan and oil that has a high smoke point.
The pan should be very hot before putting the scallops in.  Use more oil with a high smoke point and make sure the oil is very hot as well. The scallops should be defrosted and dry.