A method and system are disclosed for dispersing gas bubbles in a multiphase mixture in a production tubing in an crude oil production well or in a riser connected to such a well, by means of one or more bubble breaker assemblies in which a plurality of orifices are arranged that are located in a substantially eccentric position relative to a central axis of the tubing. The use of eccentric orifices promotes the breaking up of large gas bubbles into a large amount of smaller gas bubbles, which are finely dispersed in the fluid stream and only re-coalesce slowly into larger bubbles.