Yes, SOGGIER is a Scrabble word!

Letter values in Scrabble US: S 1, O 1, G 2, G 2, I 1, E 1, R 1.

Is it a valid word?

SOGGIER is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

(of soil) soft and watery
having the consistency of dough because of insufficient leavening or improper cooking; it's a doughy mess"
slow and apathetic