... Abstract Reliable prediction of as-laid embedment for surface-laid offshore pipelines is important for predicting seabed resistance during operation. However, the accuracy of existing methods can be limited by various challenges: difficulties in determining representative, very near-surface...

... for girth welds in risers and pipelines. Different positions of the slope transition point (STP) were used in conjunction with two-slope S-N curves in the Miner’s damage sum. By comparing the number of blocks of the histogram applied in both analyses, a suitable position for the slope transition point (STP...

... Abstract Free span in pipelines can occur intentionally either due to the seabed topography during laying, or it can be caused by scouring of the seabed during operation. A free span section can either be on its own which is known as ‘single span’ or multiple spans can be in close vicinity...

... and subsea equipment, moorings, risers, flowlines, pipelines, and umbilicals. As far as risers are concerned, industry codes and standards and government regulations for the official requirements of life extension are yet to be issued, albeit some are in the works. The general requirements for risers...

... Abstract Internal corrosion of steel pipelines before use, or temporarily taken out of use, and ‘parked’ on the seafloor for some time (months), suspended from operation or ‘abandoned’ for extensive period of time continues to be an issue for offshore operators and regulators...

... Abstract The hydrodynamic forces induced by combined irregular waves and currents acting on a small-diameter pipeline are investigated based on some physical tests. The results suggest that the Morison equation leads to poor predictions of the time-variant forces when the pipeline is mounted...

... Abstract Predicting the as-laid embedment of surface-laid pipelines and cables is important for estimating their in-service response. To date, design approaches have only considered flat seabed conditions. The as-laid embedment is estimated using vertical ‘lay down’ seabed springs...

... of this document is needed. The standard is being used for fatigue design of different structures such as jackets, risers, pipelines, semisubmersibles, spars, floating production vessels, fixed and floating structures for support of wind turbine structures, different types of connectors, etc. This implies...

... Abstract Hydrodynamic forces on small diameter subsea pipelines and cables placed near seabed are important for their on-bottom stability design. In offshore environments, these pipelines are usually subjected to extreme wave conditions. The present study investigates hydrodynamic forces acting...

... and are likely to occur in pipelines subjected to large deflections cycles such as over sleepers. Utilizing HCF approach to predict fatigue in this case is inappropriate and a strain versus number of cycles to failure (ε-2N) approach, referred to as low cycle fatigue (LCF), is typically utilized. A detailed...

... to ensure that the decision-makers have sufficiently reliable data available to decide whether hydrogen gas can be safely transported in new or existing offshore pipelines at an acceptable cost. pipelines hydrogen embrittlement H 2 transport limit states Proceedings of the ASME 2021 40th...

... Abstract For safe and cost-efficient operations of new and existing offshore Arctic pipelines, monitoring of pipeline structural integrity is imperative. A well-founded pipeline integrity management program can optimize production output, extend the life of the pipeline, and serve as a tool...

... Abstract Internally pressurised pipe behaves differently than externally pressurised pipe. DNVGL-ST-F101 [4], a prevailing standard for the design of submarine pipelines, provides limit-state equations for combined loading that are valid only if the diameter-to-wall-thickness ratio ( D/t...

... is achieved. In a typical project, more pipe joints are procured than required in order to mitigate contingencies. For pipelines, this overage is typically a percentage of the required number of joints or pipeline length. For risers, typically double the required number of joints is procured where half...

... north has brought the challenges of exploration, production, and transportation in the cold regions like Prudhoe Bay, the Mackenzie Delta, and the Arctic Islands into focus. To transport hydrocarbons to market, pipelines used in the Arctic have unique challenges and stringent design conditions that must...

... Abstract Subsea pipelines and umbilicals are used for the transportation of fluids and electrical power between subsea installations and floating production systems (FPUs). The installation and maintenance of these systems can be expensive. In a conventional subsea field development...

... Abstract The J-lay and S-lay are two common methods for SCR and pipeline installations. When using the S-lay installation method, onboard welded pipe joints leave the vessel horizontally and are guided to the seabed over a stinger structure. The pipe is lowered using tensioners...

... Abstract This paper investigates issues around four-phase (Oil/CO2/water/sand) flows occurring within pipelines. Multiphase flows are the norm, as production fluid from reservoirs typically include sand with water. However, these multi-phase flow mixtures, whether three- or four-phase...

... Abstract Soil cover, rock cover and a combination of soil and rock cover are common approaches to protecting pipelines, cables and umbilicals associated with offshore energy infrastructure. However, with the exception of a simplified rock cover case or a simplified sand cover case...

... Abstract Hard zones in large diameter pipe have been identified as the cause of the Kashagan pipelines failure, the replacement of which is estimated to cost $3.6B [1–4]. Some hard zone formation mechanisms have been known for years, but one mechanism is “new”, or more precisely, newly...