Integration of Solid Modeling Into Real-Time Navigation

Abstract

Abstract The Downed Platforms project deals with seven platforms containing 59 wells which were toppled during Hurricane Katrina in water depths ranging from 86 to 135 feet. Visibility at these depths in these locations is limited at best. As part of an effort to extend the ability of remote operated vehicles (ROV) to work in low visibility, solid models of downed platforms were built and were exported into a form which could be used in the real-time navigation system for offshore vessel, ROV and diving operations. The paper will discuss:Zero Visibility Operations - The Initial ConceptSubsea Model DevelopmentNavigation System DevelopmentIntegrating the Model with Navigation for Field DeploymentROV Control System IntegrationModel Maintenance The paper will describe techniques which could be applied to subsea navigation in complex environments, where model based positioning can deliver operational efficiencies. Key elements of this system are the structural model and the deployment of navigation system components to ensure accurate and high update rate positioning. The paper will present results from various stages of field work. While many technologies presented in the paper are pre-existing, the integration of all systems to enable continued operations in zero visibility represents a new application. The application of these technologies increased the operating envelope for the ROV, enhanced co-ordination and safety of activities in the field and in the project and presented significant advances in subsea positioning, control and navigation. Background The 2005 hurricane season was the most active on record and hurricanes Katrina and Rita inflicted major damage to Gulf of Mexico (GoM) production facilities on the outer continental shelf (OCS). Seven platforms were completely destroyed in the Grand Isle 41/43/47 field, or " downed??. All platforms located in the Grand Isle (GI) and West Delta (WD) lease areas are in water depths from 86 to 135 feet. The locations were GI 40B, GI 40F, GI 41A, GI 47C, GI 48D, WD 69C, and WD 69K (Figure 1), which are all within 20 to 35 miles west of the centerline track of Hurricane Katrina.