The plug-up of the crude oil gatheringline due to wax condensation is a common trouble occurring in the oil field.
油田集油和输油管线冻（凝）堵是油田生产常见故障之一。
2
Based on the flow mechanism and performance of gas liquid two phase plug flow in oil gas gatheringline, a slug unit are divided into both gas slug region with liquid film and liquid slug region.
Its assessment is in line with a landmark study in late 2005, "Rising Above the Gathering Storm," by the National Academies, the nation's leading science advisory group.