Gasöliquidöliquid three-phase co-current flow commonly occurs in the oil & gas production pipelines. The dynamics of three-phase flow are more complex than single and two-phase flow. High pressure drop and liquid holdup are common flow assurance problems in the upstream oil and gas production pipelines. These problems increase the energy consumption of the flow system, especially in the process of enhanced oil recovery (EOR). Three-phase flow behavior is highly dependent on the flow patterns. For an economical and energy-efficient production process, the flow pattern with less pressure drop and liquid holdup needs to be identified. In this article, three-phase flow patterns� classification and structures are critically reviewed and discussed in detail. Flow regime transition with the change in volumetric fractions and superficial velocities of phases are also elaborated. The prediction models for flow regime transition and stability, pressure drop, liquid holdup, and three-phase flow characteristics are presented. © 2020 Institution of Chemical Engineers