Sub-sea SCR/Flowline Preservation - Maintenance of Fill Fluids During the Thunder Horse Sub-sea Kit Re-installation Campaign

This paper will summarize the activities undertaken by the Thunder Horse Sub-sea Team in the maintenance of the hydrotest-fill fluids for the sub-sea production flow-line/equipment from initial fill until start-up.

Discussed will be:

• The initial fill of the Thunder Horse sub-sea system with chemically treated water and how this treatment aligned with BP and MMS/EPA requirements.
• The position that the project team took as related to the continued effectiveness of the chemically treated fill fluids, particularly with respect to the degradation of the biocide product (THPS) and its ability to mitigate the effects of microbial influenced corrosion (MIC), over extended periods leading to production start-up.
• The activities performed by the Thunder Horse project team to maintain the recommended chemical concentrations in the sub-sea system during construction activities.

Key Words: Hydrotest, THPS, MIC