Semi-submersible offshore platform

Figure 7.10 A semi-submersible offshore platform. Source http //www.mms.gov/alaska/kids/shorts/ drilplat/drilplat.htm, with permission...

The type of MIC-related problems that may be expected in, for exanple, submersible and semi-submersible platforms are, more or less, similar to stagnant water problems caused in firewater lines or pipelines. Such platforms have pontoons and columns that, when flooded with seawater, cause the pontoons to submerge to a predetermined depth. Figure 7.10 shows an example of a semi-submersible offshore platform. 

Floating exploration and production facilities are sometimes provided on jackup rigs, semi-submersible vessels or ex-crude oil shipping tankers converted to production treatment vessels. These facilities are essentially the same as fixed offshore platform or installations except they are moored in place or provided with a temporary support structure instead of provided with fixed supports to the seabed. The major process fire and explosion risks are identical to the risks produced on offshore platforms. They have one addition major facility risk, that is the maintenance of buoyancy of the installation. Should fire or explosion effects cause a loss of buoyancy (or even stability) the entire facility is at risk of submergence. Adequate compartimization and integrity assurances must be implemented in these instances. 

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