A method and a system for transporting a flow of fluid hydrocarbons containing wax and/or asphaltenes or any other precipitating solids through a treatment and transportation system including a pipeline are disclosed. The flow of fluid hydrocarbons is introduced into a reactor (4), where it is mixed with another fluid flow having a temperature below a crystallization temperature for the wax and/or asphaltenes or other solids and containing particles or crystals acting as nucleating and/or growth cores for the wax and/or asphaltenes or other solids, the mixing temperature providing precipitation of the wax and/or asphaltenes or other solids from the flow of fluid hydrocarbons, and the effluent flow of hydrocarbons and particles is conveyed from the reactor (4) to a pipeline (6) for transportation.