In the dynamic analysis of a floating structure, coupled refers to procedure in which vessel, moorings, and risers are modeled as whole system, thus allowing for interactions between various system components. Because time domain is impractical owing prohibitive computational costs, highly efficient frequency approach was developed previous work, wherein drag forces linearized. The study showed that provided geometric nonlinearity moorings/risers insignificant, often holds ultradeepwater...

Abstract A simplified framework is presented in which an existing artificial neural network (ANN) based tool for critical stress range prediction used order to rapidly assess the fatigue life of a steel catenary riser (SCR). The approach considers first-order motions hosting floater (heave, pitch and roll motions) irregular sea-states within touchdown zone (TDZ) SCR. Stress transfer functions are generated that approximate SCR TDZ due vertical motion at hang-off point. response amplitude...

In the dynamic analysis of a floating structure, coupled refers to procedure in which vessel, moorings and risers are modeled as whole system, thus allowing for interactions between various system components. Because time domain is impractical owing prohibitive computational costs, highly efficient frequency approach was developed previous work, wherein drag forces linearized. The study showed that provided geometric nonlinearity moorings/risers insignificant, often holds ultra-deepwater...

Drag anchors are often employed in offshore floating facility moorings. The standard drag anchor design approach is based on a deterministic load and resistance factor (LRFD) framework that considers characteristic “low” “high” estimates of soil strength other geotechnical parameters, combined with code-specified partial factors. A disadvantage this the resulting designs may not achieve consistent level reliability. This paper describes study addresses limitation by developing demonstrating...

This paper investigates the effect of riser-soil interaction model selection on assessment steel catenary riser (SCR) fatigue life for realistic environmental conditions at a deep-water Australian North west shelf (NWS) site. Using wave scatter diagram consisting 100 metocean site (combining irregular seas, swell and current), dynamic time-domain finite element analysis is coupled with rain-flow cycle counting algorithm in order to determine SCRs due first-order motions host floater. Rigid,...

Abstract Large diameter steel catenary risers (SCRs) are considered a cost efficient export riser solution for gas field developments at deep-water sites. However, SCRs prone to fatigue damage their interface with the seabed (the touchdown zone, TDZ) and hence accurate estimation of life is crucial. The major source TDZ motions host vessel subjected irregular ocean waves. first-order interaction between causes oscillations in all degrees freedom same frequencies as incident second-order...

Current design codes for floating offshore structures are based on measures of short-term reliability. That is, a storm is selected via an extreme value analysis the environmental conditions and reliability vessel in that computed. Although this approach yields valuable information motions, it does not produce statistically rigorous assessment lifetime probability failure. An alternative to perform long-term which consideration taken all sea states potentially encountered by during life....

Abstract In-service integrity management (IM) of steel lazy wave risers (SLWRs) can benefit significantly from quantitative assessment the overall risk system failure as it provide an effective tool for decision making. SLWRs are prone to fatigue within their touchdown zone (TDZ). This mode needs be evaluated rigorously in riser IM processes because is ongoing degradation mechanism threatening structural throughout service life. However, accurately evaluating probability systems a useful...

Abstract An accurate estimation of riser fatigue life plays a critical role in the efficient structural integrity management operating flexible risers. A more reliable estimate could, for example, enable extension aging risers or facilitate use targeted intervention program. This paper introduces data-centric paradigm monitoring which uses measured host vessel motion data as part global response analysis. The performance this method is assessed by comparison with conventional analysis...

The Malampaya Depletion Compression Platform (DCP) was conceived by Shell Philippines Exploration B.V. (SPEX) to provide additional gas compression account for the future expected decline in well pressure from field. project is very important ongoing prosperity of Philippines, with exported feeding three power stations which up 45% needs Luzon, largest and most populous island Philippines. DCP consists a sealed barge structure rigidly connected four cylindrical legs, each supported on...

This article presents summary details of the innovative scour protection design performed for Malampaya Depletion Compression Platform (DCP), which was installed 200 nautical miles south west Manila, The Philippines, adjacent and bridge linked to existing Shallow Water (SWP) at site.The DCP conceived by Shell Philippines Exploration B.V. (SPEX) provide additional gas compression account future expected decrease in well pressure from field.Once installed, will operate maintain an acceptable...