1. n. [Production Logging]

A multiphase-flow regime in horizontal or near-horizontal wells in which the fluids are separated into different layers, with lighter fluids flowing above heavier fluids. Stratified flow is more likely to occur at low flow rates and in flat or downhill sections of horizontal wells. In uphill sections, and as the flow rate increases, the interface between the fluids becomes mixed and irregular, hence the term wavy stratified flow is often used.

See related terms: annular flow,  flow structure,  multiphase flow