The occurrence of the severe slugging phenomenon in multiphase pipelines can cause serious and troublesome operational problems within the receiving process facilities. This paper describes: the pipeline operability studies on the Dunbar to Alwyn multiphase pipeline regarding riser-induced severe slugging; the control scheme selected to prevent this phenomenon; and the subsequent operating expe...

In pipeline-riser systems, pressure fluctuations which result from the formation of large liquid slugs and gas surges due to operational changes or low mass flow rate from production wells and the profile of pipeline-riser systems often lead to trips at the inlet of the separator; and thereby, the problem causes a a loss of the production.In this study, on a sample deep-water oil field off the ...

In recent years, the production of oil and gas has been developed in deep water depths which exceed 500m. Deep water developments are being followed strongly in different parts of the world (Caspian Sea, Gulf of Mexico, etc.). The movement of floater causes severe stress at the touchdown point (TDP) in steel catenary risers (SCR). The main objective of this study was to simulate the exact behav...

This paper investigates the integrated riser/vessel system which is subjected to random waves. Riser pipelines are the main components of the oil and gas offshore platforms. Whereas Iran country has been located on the fringes of Caspian Sea deep water, therefore study and research in this area is increasingly essential. The fluctuation of floating production causes the severe response and grea...

Elaborated models such as those used for simulation purposes (e.g. OLGA simulator) cannot be used for model-based control design. The focus of this paper is on deriving simple dynamical models with few state variables that capture the essential behaviour for control. We propose a new simplified dynamic model for severe slugging flow in pipeline-riser systems. The proposed model, together with f...

Statoil has designed and tested dual diameter pipeline pigs to perform various tasks during operations, precommissioning and commissioning of the 710km 42"x28" Åsgard pipeline. The concepts developed have been put through a major design and testing program to demonstrate that the various functional requirements have been met. The paper describes the development process as well as field experien...

Anti-slug control applied to two-phase flow provides a very challenging and important application for feedback control. It is important because it allows for operation that would otherwise be impossible, and challenging because of the presence of both RHP-poles and RHP-zeros. To conduct experiments on pipeline-riser anti-slug control, a small-scale slug-loop has been build. The loop has been mo...

Severe slugging is an unstable multiphase flow pattern occurs in a pipeline riser with low gas and liquid flowrates. It highly undesired practical operation because of the pressure mass oscillations induced. Riser outlet choking has shown effectiveness eliminating or reducing severity slugging. This work presents experimental numerical study on elimination severe riser-induced slug by means cho...

A suitable initial point for understanding multiphase flows is a phenomenological description of the mechanism geometric distributions or flow patterns that are observed. The challenge however prediction combination operating conditions and characteristics phases as well points transition from one pattern to other. Different occur in different pipeline configurations which U-shape risers part. ...