October 07, 2022 | Oil and Gas Blogs
Organisms may be “micro” in size, but the impact that they have on the oil and gas (O&G) industry is anything but micro.
Microorganisms are abundantly present in the O&G frameworks such as pipeline networks, vessels, reservoirs and other infrastructure. The corrosion induced by the presence of these microorganisms on the surface of a material is known as microbiologically influenced corrosion (MIC) or simply microbial corrosion. MIC, estimates indicate, account for up to 30% of all corrosion-related costs in the O&G industry.
Activities of archaea, bacteria and fungi in colonies create biofilms on the surfaces of materials, resulting in corrosion on metallic and non-metallic surfaces. These surfaces are exposed to seawater, soil, distilled water, fresh water, crude oil, process chemicals and sewage. Their exposure to microbes expedites the corrosion of alloys and metals .
Corrosion generally takes place in the presence of an amalgamation of multiple types of microorganisms. Depending on the environment, these microbes typically include metal-oxidizing bacteria, acid-producing bacteria (APB), sulfate-reducing bacteria (SRB), metal-reducing bacteria (MRB), and methanogens. MIC may result in crevice, pitting, galvanic corrosion, and sometimes dealloying in oil & gas metallic pipelines.
MIC is of significant interest to the O&G industry because it typically accounts for more than 75% of the corrosion in productive oil wells and more than 50% of failures in pipeline systems. SRB is a major cause of MIC in oil and gas pipeline systems. Moreover, reservoir souring, equipment and pipeline failures, and storage tank leakages are some key issues faced by the industry due to MIC.
A major reason for oil well failures and internal pipeline corrosion, MIC has become a prime research area in the O&G industry to develop technologies for timely detection, monitoring and mitigation. Some points supplementing development of such technologies are:
The O&G industry has conventional techniques for preventing and treating identified MIC in pipelines. These include cleaning methods such as mechanical and chemical cleaning, using oxidizing biocides (such as chlorine, bromine, ozone and hydrogen peroxide) and non-oxidizing biocides (glutaraldehyde, quaternary ammonium compounds, isothiazolones), coatings, material protection, and cathodic protection.
However, oilfield service provider Schlumberger also introduced an unconventional tool like Microbial InstaCheck, which is a rapid onsite service for real-time bacteria measurement, monitoring, and control. It uses bacteria enumeration techniques in conjunction with ChemWatcher integrated chemical management system, enabling clients to develop informed control strategies for MIC.
Timely detection and monitoring of MIC is difficult, and hence it poses significant problems throughout the oil and gas supply chain. The industry is adopting measures to take early action and mitigate its effects. This also helps protect the environment and carry out safer operations by reducing the risk of costly pipeline failures.
Few steps taken by the O&G industry are:
The O&G industry is already under pressure from various fronts given its impact on the environment, costs and the rising adoption of electric vehicles. MIC could deepen the woes for the sector if not addressed with urgency and on priority.