ASTM_F_3045_-_15.pdf

Designation:F304515Standard Test Method forEvaluation of the Type and Viscoelastic Stability of Water-in-oil Mixtures Formed from Crude Oil and Petroleum ProductsMixed with Water1This standard is issued under the fixed designation F3045;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers a procedure to determine thewater-in-oil emulsification tendencies and stabilities in thelaboratory.The results of this test method can provide oilbehavior data for input into oil spill models.1.2 This test method covers a specific method of determin-ing emulsion tendencies and does not cover other procedureswhich may be applicable to determining emulsion tendencies.1.3 The test results obtained using this test method areintended to provide baseline data for the behavior of oil andpetroleum products at sea and input to oil spill models.1.4 The test results obtained using this test method can beused directly to predict certain facets of oil spill behavior or asinput to oil spill models.1.5 The accuracy of the test method depends very much onthe representative nature of the oil sample used.Certain oilscan form a variety of water-in-oil types depending on theirchemical contents at the moment a sample is taken.Other oilsare relatively stable with respect to the type formed1.6 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.7 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Summary of Test Method2.1 Oil is mixed with 33(3.3%)saline water for 12 h ina standard rotating apparatus.The resulting mixture is charac-terized after this shaking period.2.2 The resulting mixture as created in step 2.1,is charac-terized visually,by measuring water content and by rheologicalmeasurements.The mixture is then classified as a stable,meso-stable,unstable emulsion or an entrained water mixture.Each of these four types of mixtures has different characteris-tics affecting the oils behavior once spilled.3.Terminology3.1 Definitions:3.1.1 complex modulusOne of the results of viscoelasticmeasurement,a measure of the resistance of a viscoelasticsubstance to flow under an applied dynamic stress,combiningboth the non-reversible(viscous)flow of the test substance andthe reversible(elastic)deformation of the test substance.3.1.2 emulsionA type of colloid,specifically,a dispersionof small droplets of one liquid in another.3.1.2.1 meso-stable emulsionsEmulsions which lack oneor more of the compositional factors necessary to form a stableemulsion,but which are sufficiently stable to persist for shortperiods,typically a few days.3.1.2.2 stableemulsionsEmulsionsthatpersistindefinitely,consisting of fine droplets with a rigid filminterface which resists coalescence.3.1.2.3 unstable emulsionsMixtures of water and oilwhich resolve rapidly into two phases,usually within a fewminutes to hours.There may be residual water remaining inlow percentages.3.1.2.4 water-in-oil emulsionAn emulsion consisting of acontinuous phase of oil containing a dispersed phase of water.3.1.3 entrained waterThis is not an emulsion but a me-chanical mixture of oil and water which has not separated dueto the physical properties of the water and oil.3.1.3.1 DiscussionTypically,the oil and water have simi-lar densities and the oil phase has a high viscosity.ragTheremnant of a broken water-in-oil emulsion.3.1.3.1 DiscussionRag will not reform an emulsion.Ragis thought to consist of tightly bound asphaltenes and resins.3.1.4 stability indexAn index describing the stability of anemulsion.1This test method is under the jurisdiction of ASTM Committee F20 onHazardous Substances and Oil Spill Response and is the direct responsibility ofSubcommittee F20.16 on Surveillance and Tracking.Current edition approved Oct.1,2015.Published December 2015.DOI:10.1520/F304515Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.1.4.1 DiscussionIn this standard,it is calculated usingdata derived from rheological measurements.3.1.5 storage modulusOne of the results of viscoelasticmeasurement,a measure of the elastic(reversible)deformationbehavior of a viscoelastic substance under an applied dynamicstress.4.Significance and Use4.1 A standard test is necessary to establish a behaviorpattern for spilled oils or petroleum products at different oilweathering stages.4.2 Water-in-oil mixtures vary with oil type and oil condi-tions such as weathering.Results from this test method form abaseline,and