SARA Analysis


Weatherford Laboratories provides a variety of methods for the accurate quantification and analysis of asphaltenes and SARA components.

Crude oils and bitumens can be separated into four compound classes: saturates, aromatics, resins, and asphaltenes (SARA). Separation is largely achieved based on polarity and molecular weight differences. Using the relative abundance of the four fractions, we can assess oil quality and predict potential flow assurance problems.

Traditional SARA
- Initial topping
- Asphaltene precipitation
- Maltene separation

Asphaltene and SARA analysis is used to determine the distribution of saturates, aromatics, resins, and asphaltene in topped petroleum samples. The procedure is divided into two stages: The first stage involves the precipitation and quantification of asphaltenes, while the second stage is the open-column chromatographic separation of the deasphaltene oil (maltene) into saturate, aromatic, and resin fractions.

Whole oil SARA
- Gas Chromatography
- Asphaltene precipitation
- Maltene separation

Traditional SARA involves topping the sample prior to asphaltene precipitation and maltene separation. The material lost during topping is not characterized. Weatherford Laboratories has developed an alternate technique that combines GC analysis with traditional SARA methods resulting in a SARA distribution that is more representative of the analyzed material.

Why perform Asphaltene/SARA analysis?

  • To predict flow assurance problems (in pipelines, process equipment, and in reservoir formations)

  • To determine oil quality

  • Performing Oil-oil correlations

  • Characterization of heavy oil, oil sand, tar, and bitumen

  • Identification of vertical and lateral oil quality gradients in reservoirs

  • Detection of tar mats

  • In absence of available source rock, asphaltenes can be used as surrogate for kerogen kinetics

  • Artificial maturation of asphaltene in highly biodegraded petroleum to “regenerate” biomarkers

  • Oil-source rock correlation

  • Research studies on asphaltene structure/behavior relationships

  • Preparation technique for other geochemical analyses such as biomarker and stable carbon isotope analysis

Application & Data Examples

Typical SARA interpretive plot, generated from plot template in Isologica™ software

High-quality asphaltene content and SARA data from Weatherford Laboratories provide critical information on the properties of a producible crude oil.