Improving Risk Based Inspection with Molecular Microbiological Methods

摘要

The South Arne platform is located in the Danish Sector of the North Sea and production started from the chalk reservoir in 1999. In late 2008, an increasing hydrogen sulphide (H_2S) scavenger consumption raised questions about the souring status of the field and the actual value of the implemented microbial monitoring strategy. An investigation of the increasing H_2S levels and the microbial monitoring program were initiated and molecular microbiological methods (MMM) were subsequently introduced as the preferred technology in the future microbial monitoring program. The improved monitoring program has given attention to numerous optimization possibilities within operation practice and production chemistry application. Lately, the corrosion inspection program, corrosion probe monitoring and the microbial monitoring program have been aligned to give appropriate input to a risk based inspection (RBI) program. This paper describes three field cases to which the new microbial monitoring program was applied and the decisions made were based on analysis results. Results and actions from monitoring program have inspired to implementation in the RBI program. The field cases include determination of reservoir souring microbes (sulphate reducing prokaryotes), microbial growth in seawater injection facilities and microbiologically influenced corrosion (MIC) in the produced water system at the South Arne platform.