Raman and Surface-Enhanced Raman Spectroscopy for Nonregenerative Liquid H ₂ S Scavengers and Sulfur Contaminants in the Oilfield: A Mini-Review

Hydrogen sulfide and organosulfur compounds present major safety, corrosion, and environmental risks throughout the oil and gas industry. Raman spectroscopy and its surface-enhanced variant (SERS) have emerged as indispensable analytical tools for sulfur management owing to the inherently strong Raman response of sulfur-containing functional groups. This paper consolidates recent advances in real-time, in situ monitoring of nonregenerative liquid hydrogen sulfide scavengers, quantitative tracking of scavenger depletion and byproduct formation, and elucidation of reaction mechanisms, including identification of key intermediates such as 1,3,5-thiadiazine and 1,3,5-dithiazine as well as fouling pathways involving polymeric sulfur species. Portable cartridge-based and fiber-optic Raman systems now enable rapid on-site analysis of scavengers, amines, and formaldehyde, whereas SERS, leveraging plasmonic nanostructures and charge-transfer enhancement, achieves sub-parts-per-billion detection of refractory polycyclic aromatic sulfur heterocycles, biodesulfurization metabolites, thiols, and refinery process contaminants. Additional applications include high-pressure diffusion studies and accelerated screening of novel scavengers. Future directions for the continued development of Raman, SERS, and related vibrational fingerprinting technologies are also provided, highlighting their growing role in automated dosing, predictive fouling prevention, and sustainable hydrogen sulfide management across upstream, midstream, and downstream operations.