Most skin benefits from using moisturizer, but not all moisturizers are alike. Although people with oily skin may not think they need a facial moisturizer, environmental factors-heat, cold, wind, sun-as well as indoor heating and cooling deplete moisture, leaving skin dehyrated (lacking water), even if it's oily. 
One of the first mistakes people make when using products on their skin is using a product that doesn’t necessarily fit their skin type.   But, if you are unsure, determining your type is easy. Examine how your skin feels at the end of the day. Look to see ​if your T-zone is dry, oily or somewhat normal.