- Author: Cecilie Kielland
- Keywords: Oil & Gas, Oil and gas
“Offshore pipelines are the veins on an offshore field development and represent a large part of the total investment and the value of the transported product can be enormous. DNV GL is committed to supporting the industry to work smarter, safer and greener. All three cooperation projects present an opportunity for the industry to work more efficiently, either through optimized and more reliable design, faster execution of projects, or safer and more robust operation”, says Asle Venås, Global Director for Pipelines in DNV GL.
Free Spans in Trenches JIP
Gaps between the seabed and pipeline, known as free spans, can lead to vibrations which may damage the pipeline. “Lack of knowledge about the extent of vibrations in small gaps that typically occur on sandy seabeds means the industry is conservative and is potentially over-dimensioning designs and conducting unnecessary interventions. The DNV GL JIP aims to address this problem by developing improved free span assessments which will lead to fewer interventions and reduced cost,” says Olav Fyrileiv, Project Manager, DNV GL – Oil & Gas.
The project comprises computational fluid dynamic analysis combined with a significant test programme and the outcome will be an extension of DNV GL’s Recommended Practice for Free Spanning Pipelines (DNV-RP-F105). DNV GL has already partnered with Dutch pipeline operator BBL Company V.O.F. and is now inviting other pipeline operators to also join the project.
Pipeline Repair JIP
Maintenance and modification technology on offshore pipelines is developing to accommodate deeper and harsher environments and reduce downtime. Technology and operational experience have been developed through several projects, such as remote pipeline operations using hyperbaric welding and Statoil’s successful Hot Tap operations in the North Sea.
“DNV GL is inviting the main players in the pipeline repair equipment sector to collaborate with us in reviewing recent developments in pipeline repair and maintenance. We plan to develop formalised criteria and procedures in an updated version of DNV GL’s Recommended Practice on Pipeline Subsea Repair (DNV-RP-F113). The aim is to reduce the time and cost spent on the design and execution of pipeline repairs,” says Dag Øyvind Askheim, Project Manager, DNV GL – Oil & Gas.
Design of Pipeline Components JIP
Today, internationally recognised standards and recommended practices cover the limit state design of subsea pipelines. However, such design codes only provide high level guidance on how to consider pipeline components within a pipeline system.
Currently, there is not a consistent and unified approach to the design of pipeline components. With modern pipeline standards, the pipeline design is optimised and this gap becomes even more pronounced. The objective of this JIP will be to develop an approach, based on industry experience and best practice, to pipeline component design that is compatible with a modern pipeline limit state design code such as DNV-OS-F101. “The aim is to help prevent project delays, increased costs and, in some cases, compromised safety, which can happen when the interpretation of codes is stretched. We are inviting major players working with pipeline systems and components,” says Jonathan Wiggen, Project Manager, DNV GL – Oil & Gas.