Crude Oil Assays and Fractionation
A crude oil assay is a detailed analysis that measures the quality, composition, and characteristics of crude oil. It provides key data such as gravity (API), viscosity, pour point, sulfur content, octane/cetane numbers, carbon residue, and a true boiling point (TBP) curve.
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To perform an assay, crude oil is distilled following ASTM D86 (atmospheric) and ASTM D1160 (vacuum) standards. Atmospheric distillation separates lighter fractions like naphtha, kerosene, and diesel, while heavier residues are distilled under vacuum to produce vacuum gas oil (VGO) and asphalt.
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Fractionation works by heating crude so its components condense at different levels of a column according to boiling point. This process yields refinery gases, gasoline, naphtha, kerosene, diesel, fuel oils, and bitumen.
At Texas OilTech Laboratories, we provide complete crude oil assays and fractionation analysis to evaluate crude quality, grade, and its distribution of valuable components.
Key quality measures include:
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Specific gravity and API gravity
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Sulfur content
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Octane and Cetane numbers
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Viscosity
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Carbon residue
