Yes, OXYGENIZE is a Scrabble word!

Letter values in Scrabble US: O 1, X 8, Y 4, G 2, E 1, N 1, I 1, Z 10, E 1.

Is it a valid word?

OXYGENIZE is a valid word in the official Scrabble dictionary (US) and the UK Scrabble Dictionary, but not in Words with Friends (ENABLE).

change (a compound) by increasing the proportion of the electronegative part; or change (an element or ion) from a lower to a higher positive valence: remove one or more electrons from (an atom, ion, or molecule)
dehydrogenate with oxygen
impregnate, combine, or supply with oxygen

Not playable in Scrabble US: OXYGENISE.