Significance and Use 5.1 Understanding the stability and compatibility of a petroleum product (crude oil or refinery stream, or both) is critical to facilities that receive multiple types of products and perform blending and processing operations. Blending incompatible streams can cause asphaltene precipitation with potential consequences such as but not limited to: refinery unit fouling, processing problems, throughput reduction, emulsion stabilization, pipeline and tank deposition, and equipment fouling. 5.2 The ability to predict the results of blending operations allows operators to anticipate potential problems and mitigate those problems prior to receiving the products. It also helps facilities to manage their product movements in the most effective manner to avoid future issues. 5.3 Some petroleum products are unstable without blending and understanding the stability of a product in terms of asphaltene precipitation is an important factor in product selection for refining. Products with poor stability can contribute to refinery unit fouling as well as the overall processibility and yield of that product.Scope 1.1 This test method covers the use of a basic microscope to determine the asphaltene solvency properties of bitumen, crude oil, condensate or related products, or the combinations thereof. These properties can be used to calculate the solubility parameters required to calculate and predict asphaltene stability for blending purposes, refinery unit fouling, processibility, emulsion stabilization, pipeline and tank deposition, and equipment fouling. If the solubility properties are known for two products, then the compatibility of potential blend ratios can be predicted. 1.2 This test method is limited to products that allow handling at atmospheric pressure and room temperature conditions without a significant loss of light end components. Loss of light ends will result in changes in the solubility properties of the product and may alter or bias the results, or both. Samples with vapor pressures (VPCR4 at 37.8 °C using Test Method D6377) greater than 100 kPa are not suitable for use with this test method. 1.3 This test method is primarily suited to products that are freely flowing at test conditions. Samples that are too viscous to flow at test conditions, such as semi-solids, may need to be heated to allow handling (See Annex A1.) 1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
