ASTM F3045-21

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: F3045 − 20 F3045 − 21
Standard Test Method for
Evaluation of the Type and Viscoelastic Stability of Water-in-
oil Mixtures Formed from Crude Oil and Petroleum Products
Mixed with Water
This standard is issued under the fixed designation F3045; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This test method covers a procedure to determine the water-in-oil emulsification tendencies and stabilities of crude oils and
petroleum products in the laboratory. The results of this test method can provide oil behavior data for input into oil spill models.
1.2 This test method covers a specific method of determining emulsion tendencies and does not cover other procedures that may
be applicable to determining emulsion tendencies.
1.3 The test results obtained using this test method are intended to provide baseline data for the behavior of oil and petroleum
products at sea and input to oil spill models.
1.4 The test results obtained using this test method can be used directly to predict certain facets of oil spill behavior or as input
to oil spill models.
1.5 The accuracy of the test method depends very much on the representative nature of the oil sample used. Certain oils can form
a variety of water-in-oil types depending on their chemical contents at the moment a sample is taken. Other oils are relatively stable
with respect to the type formed
1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.7 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.
1.8 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.
2. Summary of Test Method
2.1 Oil is mixed with 33 ‰ (3.3 %) saline water for 12 h in a standard rotating apparatus. The resulting mixture is characterized
after this shakingmixing period.
This test method is under the jurisdiction of ASTM Committee F20 on Hazardous Substances and Oil Spill Response and is the direct responsibility of Subcommittee
F20.16 on Surveillance and Tracking.
Current edition approved April 1, 2020Sept. 1, 2021. Published April 2020September 2021. Originally approved in 2015. Last previous edition approved in 20152020 as
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F3045–15–20. . DOI: 10.1520/F3045–20.10.1520/F3045–21.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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2.2 The resulting mixture as created in step 2.1, is characterized visually, by by visual qualities, by measuring water content and
by rheological measurements. 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 characteristics affecting the oils behavior once spilled.behavior of oil
in the aquatic environment.
3. Terminology
3.1 Definitions:
3.1.1 complex modulus—One of the results of viscoelastic measurement, a measure of the resistance of a viscoelastic substance
to flow under an applied dynamic stress, combining both the non-reversible (viscous) flow of the test substance and the reversible
(elastic) deformation of the test substance.
3.1.2 emulsion—A type of colloid, specifically, a dispersion of small droplets of one immiscible liquid in another.
3.1.2.1 meso-stable emulsions—Emulsions that lack one or more of the compositional factors necessary to form a stable
emulsion, but that are sufficiently stable to persist for short periods, typically a few hours to days.
3.1.2.2 stable emulsions—Emulsions that persist indefinitely, consisting of fine droplets with a rigid film interface which resists
coalescence.
3.1.2.3 unstable emulsions—Mixtures of water and oil that resolve rapidly into two phases, usually within a few minutes to
hours. There may be residual water remaining in low percentages.
3.1.2.4 water-in-oil emulsion—An emulsion consisting of a continuous phase of oil containing a dispersed phase of water.
3.1.3 entrained water—This is not an emulsion but a mechanical mixture of oil and water which has not separated due to the
physical properties of the water and oil.
3.1.3.1 Discussion—
Typically, the oil and water have similar densities and the oil phase has a high viscosity.
3.1.4 rag—The remnant of a broken water-in-oil emulsion.
3.1.4.1 Discussion—
Rag will not reform an emulsion. Rag is thought to consist of tightly bound asphaltenes and resins.
3.1.5 stability index—An index describing the stability of an emulsion.
3.1.5.1 Discussion—
In this standard, it is calculated using data derived from rheological measurements.
3.1.6 storage modulus—One of the results of viscoelastic measurement, a measure of the elastic (reversible) deformation behavior
of a viscoelastic substance under an applied dynamic stress.
4. Significance and Use
4.1 A standard test is necessary to establish a behavior pattern for spilled crude oils or petroleum products at different oil
weathering stages.
4.2 Water-in-oil mixtures vary with oil type and oil conditions such as weathering. Results from this test method form a baseline,
and usually are a measure of behavior at sea.
4.3 This test has been developed over many years using standardized equipment, test procedures, and to overcome difficulties
noted in other test procedures.
4.4 This test should be performed at the temperatures and degrees of weathering corresponding to the spill conditions of interest.
5. Interferences and Sources of Error
5.1 Interferences can be caused by contaminants, particularly such as residual oil or surfactants on labware, and other sample
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handling supplies and apparatus that lead to irregular results. Surfactants in particular will influence results, as small amounts will
disrupt the stability of a water-in-oil emulsion. All glassware must be thoroughly cleaned. The cleaning process includes rinsing
with dichloromethane to remove the oil, followed by rinsing three times each with tap water, purified water (reverse osmosis), and
acetone. Once cleaned, precautions must be taken to minimize contact of the labware with contaminants to prevent interferences.
5.2 Emulsion formation is somewhat susceptible to energy levels. The rotational speed of the shaker should be checkedverified
with a tachometer every day. before each use. The specified direction of rotation should be followed (vessel cap leads rotation on
start-up).
5.3 The specified fill volumes of the test vessels must be observed as the energy level varies with the amount of fill.
5.4 Temperature is a factor in emulsification, so it is important that all components (salt water, pre-mix,oil, and temperature
controlled chamber) are stable at 15° C or the selected test temperature, before starting.
5.5 The handling of the samples after the mixtures are formed is important. Care must be taken to take a representative sample.
Excess water should be avoided when sampling.
5.6 Since the test results may be affected by salinity, thorough mixing of the salt water is required. Salinity should be verified using
a salinity meter before use.
5.7 Oil sources, recovered for a source, especially crude oil sources,fields, vary much with production timeconditions and
conditions. over time. Oil samples mustshould be treated as unique considered as indicative of the oil source at a moment within
a range of variability and are not necessarily representative of all oil recovered from the source. Some oils are near the threshold
of two different water-in-oil types. Depending on the actual conditions under which thisthe oil was sampled, different results may
occur. Other oils are not as sensitive.
5.8 Additives introduced in the production and transport of oils can change their emulsification behavior. Some oils have added
asphaltene suspenders or emulsion inhibitors. These may significantly alter the outcome of this test. Information on the oil
treatment should be obtained before making the test.
6. Apparatus
6.1 2.2-litre fluorinated HDPE wide-mouth bottles, approximately 24 cm in height and 6 cm in radius (Nalgene or equivalent),
used as the test vessel. These vessels match the shaker as described below.
6.2 Variable speed end-over-end rotary mixer capable of maintaining 55 RPM, with a radius of rotation of 15 cm (7.5 cm from
center of vessel) (Associated Design or equivalent).
6.3 Automated Karl Fischer titration analyser, This device is used to measure the water content of the resulting water-in-oil
mixture.
6.4 Rheometer, with a 35 mm parallel-plate geometry, capable of functioning in forced-oscillation mode. mode with parallel plate
geometry. This device is used to measure the rheological properties of the resulting water-in-oil mixture.
6.5 Circulating bath with a range from 0 to 25 °C (60.1).
6.6 Salinometer or water quality meter, SensIon 745 or equivalent.equivalent with a sensitivity of 60.1 PSU (practical salinity
unit).
6.7 Oil-mixing devices including a shaker for mixing the small samples prior to use and devices to mix the oil contained in drums.
These devices are described in EPA standards for use in extraction tests: EPA Method 1310 Extraction Procedure (EP) Toxicity Test Method And Structural Integrity Test,
EPA Method 1311 Toxicity Characteristic Leaching Procedure (TCLP), and EPA 1312 Synthetic Precipitation Leaching Procedure (SPLP). Environmental Protection Agency
1200 Pennsylvania Avenue, N.W. Washington, DC 20460. http://www3.epa.gov/
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6.8 The following is a list of other necessary supplies. Equivalent supplies are acceptable.
6.8.1 Disposable 30- and 1-mL plastic syringes,
6.8.2 20-L plastic or glass carboy, stirring plate and stir bar.
6.8.3 Spatulas Spatulas, scoops and wide-mouth bottles for sample handling and storage,
6.8.4 Electronic timer switch.
7. Reagents
7.1 Reagents—Water purified by reverse osmosis or equivalent means is used for the test water. Fine granular sodium chloride or
table salt, non-iodized, is used for making the salt water. The typical brine solution of 33 ‰ (3.3 %) NaCl is prepared from salt
and purified water, iswater and stored in a 20 L carboy at ambient temperatures until needed. Alternate salinities may also be
prepared for testing. Reagent-grade sea salt mix (for example, SigmaAldrich or equivalent) may be substituted for preparing brine
solutions. Fresh water may also be used for the test to mimic non-saline conditions.
7.1.1 Oil—is used as received, but is shaken for 30 minutes prior to use and is maintained at the test temperature of 15 °C or the
chosen test temperature.
7.1.2 Karl Fischer reagent, 5 mg/mL H O, O is recommended, single component, pyridine free.
7.1.3 Toluene, methanol and chloroform, reagent grade, as solvent for the Karl-Fischer titration.
7.1.4 Dichloromethane and acetone, as clean-up solvents, and RO purified water
8. Procedure
8.1 Crude Oil Sample Collection and Storage—The bulk oil as received is mechanically mixed for 1 to 2 hto attain homogeneity
prior to obtaining a working sample. Working samples are stored in 2-L high-density polyethylene bottles with polypropylene
screw closures. clean, airtight containers. The working sample is mechanically shaken for 30 min at 15 °C or the selected operating
temperature prior to removing a sub-sample for testing. When not in use, all samples should be stored in a temperature-controlled
room at 5 °C.
8.2 Generating the water-in-oil mixture—In summary, water-in-oil mixtures are formed in 2.2 L fluorinated vessels on an
end-over-end rotary mixer (Associated Design, VA or equivalent) at a rotational speed of 55 RPM.
8.2.1 Each 2.2 L mixing vessel is filled with 600 mL of water, either salt or fresh water as selected for the test. The water should
be at the test temperature at the time of addition.
8.2.2 Oil is introduced at a ratio of 1:20 oil:water by adding 30 mL of the test oil to the vessel.
8.2.3 The vessels are sealed and mounted in the rotary mixer such that the cap of each mixing vessel leads the direction of rotation
to maximize the turbulence of mixing.
8.2.4 The rotary mixer and vessels are held at 15 °C or the selected operating temperature in a temperature controlled cold room
for the duration of the experiment. This temperature (15 °C) or the selected operating temperature (Note that 15 °C is the standard
temperature for measuring oil properties,properties.) If the predicted temperatures the time of temperature(s) of interests for a spill
are differentis different, the test should be performed at those predicted temperatures as well. Testing at different temperatures
necessitate that the entire study be performed at the new chosen temperature.
8.2.5 The vessels and their contents are allowed to stand for 4 h to thermally equilibrate.
ACS Reagent Chemicals, Specifications and Procedures for Reagents and Standard-Grade Reference Materials, American Chemical Society, Washington, DC. For
suggestions on the testing of reagents not listed by the American Chemical Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and
the United States Pharmacopeia and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.
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8.2.6 The mixing is initiated using an electronic timer switch. The vessels are mixed continuously for 12 h at a rotation speed of
55 RPM.
8.2.7 After 12 h mixing, the water-in-oil mixtures are collected from the vessels and transferred to appropriately sized glass
wide-mouthed jars for observation and analysis.
8.2.8 The emulsions are stored in the cold room at 15 °C or the selected operating temperature for one week, followed by
additional observation and analysis.
8.2.9 Each oil is tested in triplicate.
8.2.10 The visual observations, viscosity, viscoelastic properties and water content of the starting oil and the resulting water-in-oil
mixture are measured for comparison as outlined in the procedures described below.
8.3 Sampling and analysis—A small sample is withdrawn from each wide-mouth jar for further analysis as described below.
Analysis is performed twice, immediately after mixing and after one week.
8.4 Sample Analysis for Water Content—Water content is measured using a Metrohm 784 KFP Titrino Karl Fischer volumetric
titrator (or equivalent) and Metrohm 703 Ti Stand (or equivalent). The titre reagent is Aquastar Comp 5 (or equivalent) and the
by a volumetric titrator using an appropriate Karl Fischer reagent. The solvent is 1:1:2 methanol:chloroform:toluene. A set of three
measurements areis made for each sample.
8.5 Viscosity Measurement of oils—Dynamic viscosities of the oils are measured at 15 °C using a VT550 with rotational
viscometer using concentric cylinder geometry. The appropriate cup and spindle combination is selected on the basis of the valid
viscosity range for each type, as provided by the manufacturer. The highest suitable shear rate is selected from the manufacturer’s
guidance manual. The measurement protocol follows a one-minute ramp up to the target shear rate, holding for five minutes, then
ramping back down to zero to evaluate thixotropy. The reported value for the oil is the average viscosity over the five minutes hold
period.period of constant shear. Triplicates are performed for each sample.
8.6 Viscoelastic Measurements of the water-in-oil mixtures—The viscoelastic properties are determined on a ThermoHaake
RheoStress RS6000 rheometer with RheoWin software (or equivalent) using 35 mm plate-plate geometry in forced oscillation
mode. rotational rheometer using plate-plate geometry. The sample stage height is set for a 2.00 mm gap. gap to allow for larger
th
water droplets in the sample (1/10 the gap or less). The sample is measured at 15 °C in forced oscillation mode using a stress
sweep from 0.100 to 10.0 Pa at a frequency of one reciprocal second. Values of the complex modulus, storage modulus, loss
modulus, and tan (δ) the phase shift of the strain response (tan (δ)) are obtained in the linear viscoelastic range (stress independent
region of the stress response curve). Samples are measured in duplicate.
8.7 Data recording of the measurements—The visual observations and the data on the water content and the viscoelastic
measurements are recorded for the water-in-oil mixtures on the test day following the 12-h mixing and again after one week. The
water content and viscosity measurements are taken of the starting oil. All values are recorded to 3-significant-figure accuracy. For
the viscoelastic measurements, it is necessary to record the complex modulus (mPa), storage modulus (mPa). Viscosity modulus
(mPa) and tan delta (V/E). The water content is measured as recorded as percentage water in oil by weight. Three oil samples are
taken for the tests, the water content and viscosity are measured in triplicate and the viscoelastic measurements are taken in
duplicate.
8.8 Calibration Standards and Methods:
8.8.1 The mixing apparatus is checkedverified daily with a tachometer to ensure a rotational rate of 55 RPM 62 RPM.
8.8.2 The salinity of the salt solution is verified using a water quality meter (SensIon 745 or equivalent), 3.3%0.05 degrees
salinity or ppt.3.3.0 % 6 0.1 PSU.
8.8.3 The rheometer calibration is checked with certified viscosity standards. If the rheometer reading is out of the manufacturer’s
specification (5%(65 % mPa.s of certified value), the instrument is to be serviced by certified technicians.
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8.8.4 The Karl-Fischer titrant is calibrated following each addition to the titrant reservoir following the manufacturer’s protocol
using purified water. The relative standard deviation is acceptable if less than 1 %.
8.8.5 The Karl-Fischer titration apparatus is checked daily using purified Type 1 water (Ultrapure water as defined by laboratory
water standards) in Sample Mode. A response of 100 % 6 1 % water (by weight) is acceptable.
8.9 Cleaning Labware—A thorough cleaning program is undertaken throughout the procedure to reduce possible cross-
contamination and accumulation of contaminants on the labware. Labware is thoroughly rinsed with, DCM, cleaned with DCM
and rinsed with tap and purified (RO) water, between each experimental run. Glassware is dried at 180 °C while plastic ware is
air dried. run and allowed to dry. Rheometer spindles are cleaned with DCM and acetone.
9. Calculation and Reporting
9.1 The values of viscosity, water content and the values from the viscoelastic measurements are ev
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