Determining MODU Design Loads Using Fuel Air Explosion Modeling Scenarios
Learn how applied computational fluid dynamic (CFD) modeling scenarios to understand the threat of explosion and thermal hazards on mobile offshore drilling units (MODUs) and support the development of design blast loads at the earliest stage of structural design.
Although rare, offshore explosions can have catastrophic and disruptive consequences that not only affect personnel and the environment, but also can significantly impact industry operating standards and regulations. The threat of an accidental release of flammable materials stored on offshore drilling and production assets creates a high risk of potentially causing serious explosion and thermal hazards such as vapor cloud explosions (VCEs); so offshore asset owners must carefully consider and mitigate this risk before an asset has been designed and once it is active in the field. To support the safety of offshore personnel as well as to protect structural integrity, a controlling load case for the critical areas of an offshore asset can increase process safety and reliability.
Recognizing a need to develop guidance for determining and quantifying design blast loads for mobile offshore drilling units (MODUs), ABS Group's Advanced Engineering team initiated a technical study to establish screening level loads. Our approach involved using computational fluid dynamic (CFD) modeling to analyze potential fuel air explosion scenarios.
- Develop design basis blast loads for offshore assets
- Apply advanced software technology to analyze potential fuel air explosion scenarios in critical areas of the asset
- Perform detailed analysis to develop screening level loads using CFD modeling
- Record pressure time history results for each blast scenario
Create a 3D CAD model of the midsection of a generic MODU and identify critical areas with high risk of VCE scenario
Apply CFD modeling to analyze dispersion and explosion scenarios in critical areas such as moonpool, drill floor, main deck and upper deck
Capture worst case consequences following ignition of flammable volumes in the identified locations and record pressure time history for each explosion model
Determine maximum levels of flammable material in each volume area to define a controlling load case to be applied at the initiation of a MODU design