Hydrodynamic Analysis in Marine Operations: A Preprocessing and Postprocessing Tool

Abstract

A pre- & post-processor for modelling and analysis of marine operations to support hydrodynamic subsea installation analysis is presented in this paper. The pre-processor is automating the input model for static analysis, that also includes preliminary estimates of load effects as basis for product configuration and input parameters to dynamic analysis models, including product specific capacities and limit state criteria directly related to installation operation. Subsea installation operations will normally be weather restricted operations demanding a thorough evaluation of relevant environmental conditions. Short-term wave conditions are described by a stochastic method using wave spectra, or the deterministic design wave method. Statistical distributions are used to describe long-term and extreme value conditions, or scatter diagrams for governing sea state parameters. Joint wave-current distributions of parameters and corresponding surfaces for given exceedance probability levels are considered. The analyses establish relevant installation parameters required in order to carry out the installation operations in a safe manner. Static analysis is also used for curve stability analysis, on-bottom stability analysis, recovery analysis, J-tube pull-in analysis, tie-in analysis and sensitivity analysis. The post-processor is used to display and review the static and dynamic analysis results, including compliance with the given limit state criteria under the relevant limiting weather conditions of each operation. This also includes easy comprehension of data supported by tools that provides the ability to easily view appropriate results quantities on all model objects. Important for a fast analysis turnaround is the ability to process the data and support the user in getting the necessary information to understand the model’s hydrodynamic behaviour.