The vast majority of scallops, especially ones purchased frozen, sold in grocery stores are wet packed scallops, with water, brine, and chemicals added to them. You will never get a great sear on those but you can get a OK sear on them. Let them thaw in the fridge. Pat them dry-don't worry about pressing on them a bit-anything to help remove excess liquid. Once they are really dry place them, in a single layer, in a pan layered with paper towel. Place paper towels (dry) over the scallops and allow to sit in the fridge overnight to dry out some more, Check once or twice and if the paper towels get really soggy change them out. When ready to cook, season your scallops and get your pan smoking hot. Add oil, it should be just below the point where it starts to smoke and burst into flame. I also add a little butter at this point but not too much. Add just a few scallops to the pan, you don't want to overcrowd the pan which will make it lose too much heat. Sear on 1 side for about 2-3 minutes then flip and sear until done. If I have really fresh, dry pack scallops I like them still almost raw in the middle, but if I'm not sure about where they came from or their freshness then I cook then all the way through, just to the point of being done but not rubbery.