Richard B. Eckert

Emphasis on biofilms can improve mitigation of microbiologically influenced corrosion in oil and gas industry

Abstract From the time of construction to the point of decommissioning, oil and gas pipelines can be susceptible to internal microbiologically influenced corrosion (MIC) based on changing environmental conditions that occur over the life of the asset. Current MIC management efforts often focus on enumeration of planktonic rather than sessile microorganisms in biofilms, essentially overlooking the surface conditions that directly influence localised corrosion and MIC. Monitoring and mitigation measures that focus on the combined effects of biofilms, surface microbiological activity and corrosion provide better information for effectively managing MIC. Consideration of the relationship between biofilms and metal surfaces in the design stage of oil and gas assets can improve the ability to manage MIC in all stages of asset life. In order to move from planktonic to sessile based monitoring, pipeline operators will need improvements in the technology for sampling internal surfaces of operating pipeline systems.

Management and control of microbiologically influenced corrosion (MIC) in the oil and gas industry—Overview and a North Sea case study

Microbiologically influenced corrosion (MIC) is the terminology applied where the actions of microorganisms influence the corrosion process. In literature, terms such as microbial corrosion, biocorrosion, microbially influenced/induced corrosion, and biodegradation are often applied. MIC research in the oil and gas industry has seen a revolution over the past decade, with the introduction of molecular microbiological methods: (MMM) as well as new industry standards and procedures of sampling biofilm and corrosion products from the process system. This review aims to capture the most important trends the oil and gas industry has seen regarding MIC research over the past decade. The paper starts out with an overview of where in the process stream MIC occurs - from the oil reservoir to the consumer. Both biotic and abiotic corrosion mechanisms are explained in the context of managing MIC using a structured corrosion management (CM) approach. The corrosion management approach employs the elements of a management system to ensure that essential corrosion control activities are carried out in an effective, sustainable, well-planned and properly executed manner. The 3-phase corrosion management approach covering of both biotic and abiotic internal corrosion mechanisms consists of 1) corrosion assessment, 2) corrosion mitigation and 3) corrosion monitoring. Each of the three phases are described in detail with links to recent field cases, methods, industry standards and sampling protocols. In order to manage the corrosion threat, operators commonly use models to support decision making. The models use qualitative, semi-quantitative or quantitative measures to help assess the rate of degradation caused by MIC. The paper reviews four existing models for MIC Threat Assessment and describe a new model that links the threat of MIC in the oil processing system located on an offshore platform with a Risk Based Inspection (RBI) approach. A recent field case highlights and explains the conflicting historic results obtained through serial dilution of culture media using the most probable number (MPN) method as compared to data obtained from corrosion monitoring and the quantitative polymerase chain reaction (qPCR) method. Results from qPCR application in the field case have changed the way MIC is monitored on the oil production facility in the North Sea. A number of high quality resources have been published as technical conference papers, books, educational videos and peer-reviewed scientific papers, and thus we end the review with an updated list of state-of-the-art resources for anyone desiring to become more familiar with the topic of MIC in the upstream oil and gas sector.

Residual life predictions—extending service life

Abstract Oil and gas production, processing, and transportation assets are designed, constructed, and operated on the basis of a finite design life. The design life is based on assumptions made in regard to various degradation mechanisms and corrosion mitigation measures that are relevant to the asset, particularly external and internal corrosion. When an asset reaches the end of its design life, the operator may wish to extend its service life beyond the original design. A formalized life extension process can be applied to demonstrate that system integrity will be acceptable to the end of the new extended service life. In the process, the past operating conditions and inspection history are evaluated to assess the current condition of the asset and to examine the potential for future corrosion damage. Uncertainties in remaining life prediction originate from the lack of information about the effectiveness of corrosion control measures and how changing production conditions will affect corrosion mechanisms in the future.