Normal conditions for WET gas

Hi everybody, need you advice! So the situation: Customer need a gas compressor, and gas is a hydrocarbon mix (methane+ethane ..etc) + water. The water dew point is below inlet/discharge temperature of the gas so no water drops as liquid.

Customer indicated the gas flow as 3000 nm3/h. and indicated nm3/h is @ 0 degC, 1,013 bara, 0% relative humidity.
How can it be? How can i select the compressor, using the flow data when there will always be some amount of water inside the gas?

;? Thank you!