Submarine pipeline systems

2007

In order to ensure the safe and continuous operation of GreenStream Pipeline System, an Integrated Management System (GIMS) has been activated since the system began its operating life in October 2004. The scope of this paper is to present GIMS and its principal components. The operability of a submarine pipeline can be assured by a suitable Inspection and Maintenance (I&M) Program able to provide timely information on potentially dangerous conditions or damages and to activate corrective measures to maintain the safe transport of gas. Seabed mobility, unexpected corrosion or human activities such as marine traffic and fishing activities are among the possible causes of damages to the submarine pipeline that I&M Program is conceived to face and correct. The inspection of the pipeline is carried out both externally and internally; the criteria, methodology and the equipment used for the inspection campaigns are described in the paper. A sophisticated data management system used to detect possible anomalies in the system and to maintain the historical data archive is also presented. To pursue its commitment to protect and enhance human and natural resources GreenStream has activated a Health-Safety-Environment Integrated Management System (IMS), also described in this paper, that sets the guidelines to satisfy the legal obligations and the most advanced health, safety and environmental standards.

2016

Journal of Transportation Engineering, 1993

Submarine oil pipelines carry hot crude oil obtained from offshore oil wells to an onshore location. As the flow proceeds, the crude oil progressively cools down, drastically changing its kinematic viscosity. This cooling increases the surface resistance to flow considerably. Analysis of such a pipeline is complicated because it involves a large number of variables representing fluid, flow, thermal properties, and geometry. Furthermore, as the liquid cools down the flow may change from turbulent to laminar. This paper reports a unified friction factor equation valid in laminar as well as in turbulent flow that deals with this complex flow situation. This equation can aid development of a methodology for analysis and design of offshore pipelines.

Water Science and Technology - WATER SCI TECHNOL, 1995

The compu!erization of pipeline design is relatively important for the engineering feasibility of submarine pipelines. The changing environmental conditions make diffICulties for the stability calculation of eacb pipe segment on line. For this reason. the computer study will provide many advanlages during the design of pipeline. The different environmental and functional parameters can be easily tried on line and the most suilable size of structure against the extreme environmental conditions can be determined. This study deals with the general design principles especially including the engineering studies, i.e. wave statistical analysis, transformation of waves. slability analysis, and developed computer program to achieve both the slabilization of pipeline and aid for drawing the route together with user in some slages of the design. FmalIy, the outline of the program is briefly desaibed and a flow chan is presented.

Computers & Structures, 1995

Routing of the pipeline is a very important aspect to be considered in the design and installation of submarine pipelines. Depending on the bathymetric conditions and the pipeline characteristic features, the bending stresses on the pipeline varies. These stresses will change and hence the design stresses on the pipeline cannot be taken as constant. To fix the safe pipeline parameters such as outer diameter, inner diameter, submerged weight and the anchorage length, pipeline software is required for online routing analysis. In this pipeline routing software, resultant bending stresses are found due to loading on the vertical plane, and the horizontal plane is considered. The current forces acting on the pipeline are assumed as horizontal loading, which is resisted by the lateral frictional resistance. In the analysis, the seabed is having various slopes, seabed depressions (or pockmarks) and the elevated rocky outcrops is considered. These parameters change with respect to site and environmental conditions. Also, in the routing, a number of routes have to be analyzed to find the optimum route with respect to the input pipeline parameters and environmental site conditions. The optimum route of the number of possible pipeline routes is selected based on the permissible stress of the pipeline. The pipeline routing software is written in FORTRAN.

2014