ABSTRACT
Accomplished in this paper is the stability appraisal of a 43,620kN barge-ladden oil rig platform in the mangrove swamp of southern Nigeria. The rig is to be deployed to a dredged slot and while in place it is meant to be ballasted prior to the oil drilling exercise. The appraisal of the rig-soil system was carried out using analytical methods and based on the operational requirements of the rig, soil condition and tidal information. The ratio of the bearing resistance to the rig load was found to be greater than 20; indicating that ultimate limit state is ensured. Serviceability limit state checks gave 207mm consolidation settlement which was estimated to occur over 18years period. Within the 10 months period over which the oil drilling exercise is planned, only about 25% degree of consolidation is expected. The results suggest that the operational minimum freeboard of 0.61m will be not exceeded.
