Relevance. Chemical demulsification plays an important role in ensuring the quality of export oil. At the same time, holistic approach to chemical treatment of well fluid is hampered by empirical methods of efficiency testing and quality assurance procedures of demulsifiers non-specific to their formulation. Aim. Obtaining comprehensive information on the composition of chemical products for separating water-oil emulsions in current use by Russian operators. Methods. Infrared spectroscopy. Results and conclusions. Analysis of over 70 commercial demulsifiers from the current portfolio of domestic suppliers has shown that the principal component of the active base are block copolymers of ethylene and propylene oxides, with outer ethylene oxide blocks ranging in content from 15 to 45 mol% and molecular weight of 4000–12000 g/mol. In less than half of all cases the active components include up to 3–5 wt% oxyalkylated alkylphenols and/or esters. A review of domestic and foreign laboratory studies has confirmed that structures with 20–40 mol% external polyethylene glycol blocks and molecular weight of 4000–7000 g/mol based on diols and diamines possess the maximum separation efficiency for dispersive systems comprising hydrocarbon and aqueous phases. Corresponding dendrimers based on polyfunctional polymerization initiators weigh 10000–20000 g/mol. The experimental conclusions of this work diverge from literature recommendations to treat water-oil emulsions using multicomponent products, incorporating alkylphenol formaldehyde resins, polyurethanes, sulfonic acids and sulfonates, nitrogen- and phosphorus-containing compounds in addition to aliphatic polyethers. At the same time, the results obtained allow for streamlining demulsifier testing protocols by excluding obviously inactive and duplicate products based on their structural characteristics.