A technique facilitates mixing of fluids for use in well treatment operations. According to an embodiment, a dry powder material, e.g. a friction reducer, may be thoroughly mixed into fluid or fluids associated with a well treatment operation. The powder material is combined with liquid, e.g. water, via a series of Venturi mixers arranged to thoroughly mix the materials. In some applications, the Venturi mixers are mounted on a modular unit which is readily moved to a desired wellsite. Additional modular units may be added to increase the amount of product being mixed according to the demands of a given well treatment operation, e.g. a hydraulic fracturing operation.