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...

A steel catenary riser (SCR) attached to a floating platform at its upper end encounters fluctuations in and near its touchdown zone (TDZ), which causes the interaction with the seabed. Subsea surveys and the analysis of SCR’s indicated that the greatest stress and highest damage occurred near the touchdown point (TDP), where the SCR first touches the seabed. Nowadays, the linear seabed spring ...

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...

Several factors can affect the response of steel catenary risers (SCR) around its touch down zone (TDZ). These include stiffness soil, soil suction force on riser TDZ, degradation with cyclic TDZ loading, etc. Riser strength and fatigue computation are usually performed considering flat seabed use rigid or linear (spring) interaction model. However, bathymetric information obtained for SCR lay ...

Prior to rotary coring, a range of soft-sediment coring tools were deployed to recover the sediment-water interface and the upper few metres of strata, whose integrity was threatened by embedment of the sea riser for drilling of the ANDRILL (AND)-1A/1B holes. These coring options included (1) a sediment gravity corer deployed through the ice-shelf hole, and (2) a push corer deployed through the...

The development of seabed trench by the steel catenary riser (SCR) touch-down zone (TDZ) in its early life can be caused installation loads, direct hydrodynamic and vessel first second-order motions on SCR. This paper presents a numerical technique which pre-trench initiated for fatigue response calculations during SCR detailed design analysis. Examples are presented to demonstrate new approach...

This study proposed a novel experimental platform to conduct dynamic loading tests of truncated model steel catenary riser (SCR) within the touchdown zone (TDZ). The facilities platform, including soil tank, system, and stirring were introduced in detail. parameters test determined through simulation an situ riser. A pipe was adopted as riser, with its outer diameter equaling that prototype SCR...

This doctoral thesis presents new research results on the control of top tensioned risers in deep waters. The main motivation for this work is the development of a riser control system which control the top tension of the individual risers in an array, such that collisions between adjacent risers are prevented. The risk of collision increases with increasing water depth, and as the oil and gas ...