As is well-known, a major problem for the management of oil and gas pipelines is corrosion influenced by microorganisms particularly, but not exclusively, bacteria. The present study focuses on the influence particularly of the sulfate reducing prokaryotes
on the internal corrosion of water injection pipelines. The research is based on reports from long-term observations of several water injections pipelines from the North Sea continental shelf. Observation data taken into consideration are pigging operation
information, composition of corrosion products and their amount, corrosion rates and pipe geometry, identified biological consortia, water chemistry and process parameters. Observations regarding water quality and mitigation methods are made also.
The distribution of corrosion including pitting and ‘features’ along the pipeline as well as the localization of these in relation to the orientation of the surfaces, is considered. This includes different corrosion patterns along the pipeline and the relative
severity of six o’clock corrosion. These observations are then used to make correlation estimates between severity and location of corrosion and service history and the local environmental conditions, where this information is available.
The correlations are used to develop a clearer view of the proportion of biocorrosion contributing to the total corrosion in water injection pipelines. Additionally, an assessment is made of the efficiency of mitigation procedures such as biocide treatments
and pigging operations.
The paper provides possible explanations for different rates and spatial patterns of corrosion for water injection pipelines transporting seawater.
The present study is part of a joint Research Training Project, BIOCOR ITN, with the focusing on biocorrosion in the oil and gas industry.
The research leading to these results has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement n° 238579. Project website: www.biocor.eu/ip IP6 (RSP 2).