ASTM D7829-13(2018)
(Guide)Standard Guide for Sediment and Water Determination in Crude Oil
Standard Guide for Sediment and Water Determination in Crude Oil
SIGNIFICANCE AND USE
3.1 Theoretically, all of the sediment and water determination methods are valid for crude oils containing from 0 % to 100 % by volume sediment and water; the range of application is specified within the scope of each method. The round robins for all methods were conducted on relatively dry oil. All precision and bias statements included in the methods are based upon the round robin data. Analysis becomes more challenging with crude oils containing higher water contents due to the difficulty in obtaining a representative sample, and maintaining the sample quality until analysis begins.
3.2 Currently, Karl Fischer is generally used for dry crude oils containing less than 5 % water. Distillation is most commonly used for dry and wet crude oils and where separate sediment analysis is available or in situations where the sediment result is not significant. The laboratory centrifuge methods allow for determination of total sediment and water in a single analysis. The field centrifuge method is used when access to controlled laboratory conditions are not available.
3.3 In the event of a dispute with regard to sediment and water content, contracting parties may refer to the technical specifications table to determine the most appropriate referee method based upon knowledge of and experience with the crude oil or product stream.
SCOPE
1.1 This guide covers a summary of the water and sediment determination methods from the API MPMS Chapter 10 for crude oils. The purpose of this guide is to provide a quick reference to these methodologies such that the reader can make the appropriate decision regarding which method to use based on the associated benefits, uses, drawbacks and limitations.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 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.
1.4 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.
General Information
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Buy Standard
Standards Content (Sample)
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.
Designation: D7829 − 13 (Reapproved 2018)
Manual of Petroleum Measurement Standards (MPMS), Technical Report 2573
Standard Guide for
Sediment and Water Determination in Crude Oil
This standard is issued under the fixed designation D7829; 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 D4007 Test Method forWater and Sediment in Crude Oil by
the Centrifuge Method (Laboratory Procedure) (API
1.1 This guide covers a summary of the water and sediment
MPMS Chapter 10.3)
determination methods from the API MPMS Chapter 10 for
D4057 Practice for Manual Sampling of Petroleum and
crude oils. The purpose of this guide is to provide a quick
Petroleum Products (API MPMS Chapter 8.1)
reference to these methodologies such that the reader can make
D4177 Practice for Automatic Sampling of Petroleum and
the appropriate decision regarding which method to use based
Petroleum Products (API MPMS Chapter 8.2)
on the associated benefits, uses, drawbacks and limitations.
D4377 Test Method forWater in Crude Oils by Potentiomet-
1.2 The values stated in SI units are to be regarded as
ric Karl Fischer Titration
standard. No other units of measurement are included in this
D4807 Test Method for Sediment in Crude Oil by Mem-
standard.
brane Filtration
1.3 This standard does not purport to address all of the D4928 Test Method for Water in Crude Oils by Coulometric
safety concerns, if any, associated with its use. It is the
Karl Fischer Titration
responsibility of the user of this standard to establish appro- D5854 Practice for Mixing and Handling of Liquid Samples
priate safety, health, and environmental practices and deter-
of Petroleum and Petroleum Products (API MPMS Chap-
mine the applicability of regulatory limitations prior to use. ter 8.3)
1.4 This international standard was developed in accor- 3
2.2 API Standards:
dance with internationally recognized principles on standard-
API MPMS Chapter 8.1 Standard Practice for Manual Sam-
ization established in the Decision on Principles for the
pling of Petroleum and Petroleum Products (ASTM
Development of International Standards, Guides and Recom-
D4057)
mendations issued by the World Trade Organization Technical
API MPMS Chapter 8.2 Standard Practice for Automatic
Barriers to Trade (TBT) Committee.
Sampling of Petroleum and Petroleum Products (ASTM
D4177)
2. Referenced Documents
API MPMS Chapter 8.3 Standard Practice for Mixing and
2.1 ASTM Standards:
Handling of Liquid Samples of Petroleum and Petroleum
D473 Test Method for Sediment in Crude Oils and Fuel Oils
Products (ASTM D5854)
by the Extraction Method (API MPMS Chapter 10.1)
MPMS Chapter 10.1 Standard Test Method for Sediment in
D4006 Test Method for Water in Crude Oil by Distillation
Crude Oils and Fuel Oils by the Extraction Method
(API MPMSChapter 10.2)
(ASTM D473)
MPMS Chapter 10.2 Standard Test Method for Water in
Crude Oil by Distillation (ASTM D4006)
This guide is under the jurisdiction of ASTM Committee D02 on Petroleum
MPMS Chapter 10.3 Standard Test Method for Water and
Products, Liquid Fuels, and Lubricants and the API Committee on Petroleum
Sediment in Crude Oil by the Centrifuge Method (Labo-
Measurement, and is the direct responsibility of Subcommittee D02.02 /COMQ the
ratory Procedure) (ASTM D4007)
joint ASTM-API Committee on Hydrocarbon Measurement for Custody Transfer
(JointASTM-API).Thisguidehasbeenapprovedbythesponsoringcommitteesand MPMS Chapter 10.4 Determination of Water and/or Sedi-
accepted by the Cooperating Societies in accordance with established procedures.
ment in Crude Oil by the Centrifuge Method (Field
This practice was issued as a joint ASTM-API standard in 2013.
Procedure)
Current edition approved Oct. 1, 2018. Published November 2018. Originally
ɛ1
MPMS Chapter 10.7 Standard Test Method for Water in
approved in 2013. Last previous edition approved in 2013 as D7829 – 13 . DOI:
10.1520/D7829-13R18.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on Available from American Petroleum Institute (API), 1220 L. St., NW,
the ASTM website. Washington, DC 20005-4070, http://www.api.org.
© Jointly copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, USA and the American Petroleum Institute (API), 1220 L Street NW, Washington DC 20005, USA
D7829 − 13 (2018)
Crude Oils by Potentiometric Karl Fischer Titration determine that the mixing time is sufficient without undue
(D4377) temperature increases.
MPMS Chapter 10.8 Standard Test Method for Sediment in
4.4 Sampling error can be a source of bias in analytical
Crude Oil by Membrane Filtration (D4807)
methods. This is reflected in the precision and bias statement
MPMS Chapter 10.9 Standard Test Method for Water in
for each method, but it should be considered when evaluating
CrudeOilsbyCoulometricKarlFischerTitration(D4928)
methods.Alarger sample size will increase the probability that
asampleisrepresentativeoftheentireparcelandcanminimize
3. Significance and Use
the potential bias arising from a less homogenous sample
3.1 Theoretically, all of the sediment and water determina-
stream. Measuring sample size by weight using an analytical
tion methods are valid for crude oils containing from 0 % to
balance is not subject to human error; measuring sample size
100 % by volume sediment and water; the range of application
by volume using analytical glassware is a source of human
is specified within the scope of each method. The round robins
error.
for all methods were conducted on relatively dry oil. All
4.5 When sample size is determined by weight, consider the
precision and bias statements included in the methods are
type of analytical balance used to weigh the sample. Ensure
based upon the round robin data. Analysis becomes more
that the resolution is appropriate, having sufficient significant
challenging with crude oils containing higher water contents
figures, for the analysis.
due to the difficulty in obtaining a representative sample, and
maintaining the sample quality until analysis begins.
5. Report
3.2 Currently, Karl Fischer is generally used for dry crude
Water Only Determination Methods
oils containing less than 5 % water. Distillation is most
commonly used for dry and wet crude oils and where separate
5.1 MPMS Chapter 10.4, Determination of Water and/or
sediment analysis is available or in situations where the
Sediment in Crude Oil by the Centrifuge Method (Field
sediment result is not significant. The laboratory centrifuge
Procedure):
methods allow for determination of total sediment and water in
NOTE 1—ASTM Test Methods D96 for Water and Sediment in Crude
a single analysis. The field centrifuge method is used when
Oil By Centrifuge (Field Procedure), the technically equivalent ASTM
access to controlled laboratory conditions are not available.
standard was withdrawn without replacement in 2000.
3.3 In the event of a dispute with regard to sediment and
5.1.1 Range of Application:
water content, contracting parties may refer to the technical
5.1.1.1 There is no approved precision and bias statement
specifications table to determine the most appropriate referee
for this method.
method based upon knowledge of and experience with the
5.1.1.2 The practical minimum detection limit is 0.025 %
crude oil or product stream.
v/v water. Lower concentrations of water should be reported as
less than 0.025 % v/v or 0 % v/v.
4. Procedure
5.1.1.3 This scope of the method indicates that it applies to
4.1 To obtain the total sediment and water results when the
crude oil, there is no water content specified in the scope.
two are determined by separate methods: First, add the raw,
5.1.2 Interferences, Biases, and Limitations:
unrounded results together, and then round the sum to the
5.1.2.1 The round robin for this method was conducted for
correct significant figure.
combined sediment and water, not the sediment or water
4.2 It is critically important that the analytical samples are
fractions separately. Therefore the precision and bias state-
collected and handled with careful regard to ensure that they
ments do not apply to analysis of water only.
are representative of the entire parcel. The crude oil or product
5.1.2.2 This method will typically quantify light alcohols
stream should be homogenous at the sampling point, and the
such as, (but not limited to), methanol and ethanol in the water
sample properly mixed prior to analysis. Sub-samples should
fraction, biasing the water result high.
not be allowed to settle prior to transfer into an analytical
5.1.2.3 Centrifuge tubes may be filled directly from a
device such as a centrifuge tube, distillation apparatus, or
sample tap and analyzed minimizing sample handling. Mini-
extraction thimble. Refer to API MPMS Chapter 8.1 (ASTM
mizing sample handling helps to maintain the representative
D4057) Standard Practice for Manual Sampling of Petroleum
nature of a sample.
and Petroleum Products, API MPMS Chapter 8.2 (ASTM
5.1.2.4 A50 mL sample is used for analysis as measured in
D4177) Standard Practice for Automatic Sampling of Petro-
the centrifuge tube.
leum and Petroleum Products, API MPMS, and Chapter 8.3
5.1.2.5 The variety of acceptable solvents allows the user to
(ASTM D5854) Standard Practice for Mixing and Handling of
match the best solvent to the crude type. This can minimize
Liquid Samples of Petroleum and Petroleum Products for
bias resulting from precipitated material (asphaltenes or paraf-
appropriate sample collection and mixing.
fins) being measured as sediment.
4.3 Itisimperativethateverysampleismixedsufficientlyto 5.1.2.6 This method will not measure dissolved water, thus
ensure that it is homogeneous. However, with prolonged the results may be biased low in crudes with dissolved water.
mixing the temperature of the sample will increase. This will In addition, depending upon the efficiency of the emulsion
decrease the representative nature of the sample due to breaker used, some highly stable emulsions may not fully
evaporative losses. The mixing system must be evaluated to break down which will bias the results low.
D7829 − 13 (2018)
5.1.2.7 The sensitivity of this method is limited to the 5.3.2.1 This test method may be appropriate for crude oils
divisions marked on centrifuge tubes.The intervals range from and products which contain light alcohols such as, but not
0.025 % to 12.5 % by volume of sediment and water. limited to, methanol and ethanol. However, no samples con-
5.1.2.8 The method is not highly prescriptive, and lack of taining alcohols were used in the round robin study; conse-
consistency may be a source of variability in the results. quently the precision and bias statements in the test method do
5.1.2.9 Because the user reads the result directly off the not apply.
glassware, result interpretation is susceptible to human error.
5.3.2.2 Mercaptans in crude oils will bias the results high.
5.1.2.10 Because this method is often performed in an
This interference is limited with the use of pyridine free
uncontrolled environment, maintaining “stoppered” tubes
reagents. The titration speed and sensitivity settings on Karl
throughout the entire analytical process may help maintain the
Fischer units may also mitigate the interference. Refer to the
representative nature of the sample.
method for information about mercaptan bias.
5.3.2.3 This test method allows the user flexibility with
5.2 MPMS Chapter 10.2 (ASTM D4006, IP 358/82), Stan-
dard Test Method for Water in Crude Oil by Distillation: implementation, the lack of consistency may be a source of
variability in the results.
5.2.1 Range of Application:
5.2.1.1 The scope of this test method does not indicate a
5.3.2.4 Syringes of sample may be drawn directly from the
range of water content. The round robin, upon which the
sample vessel of they may be drawn from a subsample
precisionandbiasstatementwasdeveloped,rangedfrom0.1%
container. The syringe contents are then transferred to the
to 1 % water by volume.
titration vessel. The use of a subsample container and the
5.2.1.2 Thepracticalminimumdetectionlimitis0.025%by
syringe are a source of error.
volume.Lowerconcentrationsofsedimentandwatershouldbe
5.3.2.5 The analytical sample size is 1 g to 5 g of crude oil.
reported as less than 0.025 % v/v or 0 % v/v.
5.3.2.6 The resolution for this test method is in the nearest
5.2.2 Interferences, Biases, and Limitations:
hundredth 0.08 mass % for relatively dry crude up to the
5.2.2.1 This test method will typically quantify light alco-
nearest 0.4 mass % for wetter crude oils.
hols such as, but not limited to, methanol and ethanol in the
5.3.2.7 This repeatability for this test method ranges from
water fraction, biasing the water result high.
0.012 for 0.05 mass % of water to 0.040 mass % for 2.0 mass
5.2.2.2 Volumetric glassware may be filled directly from a
% of water.
sample tap. The volumetric glassware is rinsed with multiple
5.3.2.8 Due to the non-prescriptive flexibility in selection of
portions of solvent to ensure full transference of sample into
solvents and titration parameters, the potentiometric Karl
the distillation apparatus.This helps ensure that sample did not
Fischermethodmayhavegreaterinterferencefrommercaptans
settle prior to collection of analytical portions. If the sample is
than the coulometric method.
allowed to settle, the representative nature may be in question.
5.3.2.9 Samplesandaliquotsinsecondarycontainers,which
5.2.2.3 Samplesusedforanalysisrangefrom5 gto200 gor
includes syringes, may stratify over time and bias the results.
mL, with the smaller sample used for crude oils containing a
higher water content. 5.3.2.10 This test method requires weighing the sample, but
5.2.2.4 The sensitivity of this test method is limited to the does not include a balance as required equipment.
divisions marked on the distillation trap. The intervals range
5.3.2.11 This test method allows manual titration using
from0.125 %to0.5 %waterbyvolume.Theintervalsincrease
Karl-Fischer reagent. Because the user reads the result directly
as the water content of the crude oil increases.
off the glassware, result interpretation is susceptible to human
5.2.2.5 The repea
...
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D7829 − 13 (Reapproved 2018)
Manual of Petroleum Measurement Standards (MPMS), Technical Report 2573
Standard Guide for
Sediment and Water Determination in Crude Oil
This standard is issued under the fixed designation D7829; 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 D4007 Test Method for Water and Sediment in Crude Oil by
the Centrifuge Method (Laboratory Procedure) (API
1.1 This guide covers a summary of the water and sediment
MPMS Chapter 10.3)
determination methods from the API MPMS Chapter 10 for
D4057 Practice for Manual Sampling of Petroleum and
crude oils. The purpose of this guide is to provide a quick
Petroleum Products (API MPMS Chapter 8.1)
reference to these methodologies such that the reader can make
D4177 Practice for Automatic Sampling of Petroleum and
the appropriate decision regarding which method to use based
Petroleum Products (API MPMS Chapter 8.2)
on the associated benefits, uses, drawbacks and limitations.
D4377 Test Method for Water in Crude Oils by Potentiomet-
1.2 The values stated in SI units are to be regarded as
ric Karl Fischer Titration
standard. No other units of measurement are included in this
D4807 Test Method for Sediment in Crude Oil by Mem-
standard.
brane Filtration
1.3 This standard does not purport to address all of the
D4928 Test Method for Water in Crude Oils by Coulometric
safety concerns, if any, associated with its use. It is the Karl Fischer Titration
responsibility of the user of this standard to establish appro-
D5854 Practice for Mixing and Handling of Liquid Samples
priate safety, health, and environmental practices and deter- of Petroleum and Petroleum Products (API MPMS Chap-
mine the applicability of regulatory limitations prior to use.
ter 8.3)
1.4 This international standard was developed in accor- 3
2.2 API Standards:
dance with internationally recognized principles on standard-
API MPMS Chapter 8.1 Standard Practice for Manual Sam-
ization established in the Decision on Principles for the
pling of Petroleum and Petroleum Products (ASTM
Development of International Standards, Guides and Recom-
D4057)
mendations issued by the World Trade Organization Technical
API MPMS Chapter 8.2 Standard Practice for Automatic
Barriers to Trade (TBT) Committee.
Sampling of Petroleum and Petroleum Products (ASTM
D4177)
2. Referenced Documents
API MPMS Chapter 8.3 Standard Practice for Mixing and
2.1 ASTM Standards:
Handling of Liquid Samples of Petroleum and Petroleum
D473 Test Method for Sediment in Crude Oils and Fuel Oils
Products (ASTM D5854)
by the Extraction Method (API MPMS Chapter 10.1)
MPMS Chapter 10.1 Standard Test Method for Sediment in
D4006 Test Method for Water in Crude Oil by Distillation
Crude Oils and Fuel Oils by the Extraction Method
(API MPMSChapter 10.2)
(ASTM D473)
MPMS Chapter 10.2 Standard Test Method for Water in
Crude Oil by Distillation (ASTM D4006)
This guide is under the jurisdiction of ASTM Committee D02 on Petroleum
MPMS Chapter 10.3 Standard Test Method for Water and
Products, Liquid Fuels, and Lubricants and the API Committee on Petroleum
Sediment in Crude Oil by the Centrifuge Method (Labo-
Measurement, and is the direct responsibility of Subcommittee D02.02 /COMQ the
ratory Procedure) (ASTM D4007)
joint ASTM-API Committee on Hydrocarbon Measurement for Custody Transfer
MPMS Chapter 10.4 Determination of Water and/or Sedi-
(Joint ASTM-API). This guide has been approved by the sponsoring committees and
accepted by the Cooperating Societies in accordance with established procedures.
ment in Crude Oil by the Centrifuge Method (Field
This practice was issued as a joint ASTM-API standard in 2013.
Procedure)
Current edition approved Oct. 1, 2018. Published November 2018. Originally
ɛ1
MPMS Chapter 10.7 Standard Test Method for Water in
approved in 2013. Last previous edition approved in 2013 as D7829 – 13 . DOI:
10.1520/D7829-13R18.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on Available from American Petroleum Institute (API), 1220 L. St., NW,
the ASTM website. Washington, DC 20005-4070, http://www.api.org.
© Jointly copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, USA and the American Petroleum Institute (API), 1220 L Street NW, Washington DC 20005, USA
D7829 − 13 (2018)
Crude Oils by Potentiometric Karl Fischer Titration determine that the mixing time is sufficient without undue
(D4377) temperature increases.
MPMS Chapter 10.8 Standard Test Method for Sediment in
4.4 Sampling error can be a source of bias in analytical
Crude Oil by Membrane Filtration (D4807)
methods. This is reflected in the precision and bias statement
MPMS Chapter 10.9 Standard Test Method for Water in
for each method, but it should be considered when evaluating
Crude Oils by Coulometric Karl Fischer Titration (D4928)
methods. A larger sample size will increase the probability that
a sample is representative of the entire parcel and can minimize
3. Significance and Use
the potential bias arising from a less homogenous sample
3.1 Theoretically, all of the sediment and water determina-
stream. Measuring sample size by weight using an analytical
tion methods are valid for crude oils containing from 0 % to
balance is not subject to human error; measuring sample size
100 % by volume sediment and water; the range of application
by volume using analytical glassware is a source of human
is specified within the scope of each method. The round robins
error.
for all methods were conducted on relatively dry oil. All
4.5 When sample size is determined by weight, consider the
precision and bias statements included in the methods are
type of analytical balance used to weigh the sample. Ensure
based upon the round robin data. Analysis becomes more
that the resolution is appropriate, having sufficient significant
challenging with crude oils containing higher water contents
figures, for the analysis.
due to the difficulty in obtaining a representative sample, and
maintaining the sample quality until analysis begins.
5. Report
3.2 Currently, Karl Fischer is generally used for dry crude
oils containing less than 5 % water. Distillation is most Water Only Determination Methods
commonly used for dry and wet crude oils and where separate
5.1 MPMS Chapter 10.4, Determination of Water and/or
sediment analysis is available or in situations where the
Sediment in Crude Oil by the Centrifuge Method (Field
sediment result is not significant. The laboratory centrifuge
Procedure):
methods allow for determination of total sediment and water in
NOTE 1—ASTM Test Methods D96 for Water and Sediment in Crude
a single analysis. The field centrifuge method is used when
Oil By Centrifuge (Field Procedure), the technically equivalent ASTM
access to controlled laboratory conditions are not available.
standard was withdrawn without replacement in 2000.
3.3 In the event of a dispute with regard to sediment and
5.1.1 Range of Application:
water content, contracting parties may refer to the technical
5.1.1.1 There is no approved precision and bias statement
specifications table to determine the most appropriate referee
for this method.
method based upon knowledge of and experience with the
5.1.1.2 The practical minimum detection limit is 0.025 %
crude oil or product stream.
v/v water. Lower concentrations of water should be reported as
less than 0.025 % v/v or 0 % v/v.
4. Procedure
5.1.1.3 This scope of the method indicates that it applies to
4.1 To obtain the total sediment and water results when the
crude oil, there is no water content specified in the scope.
two are determined by separate methods: First, add the raw,
5.1.2 Interferences, Biases, and Limitations:
unrounded results together, and then round the sum to the
5.1.2.1 The round robin for this method was conducted for
correct significant figure.
combined sediment and water, not the sediment or water
4.2 It is critically important that the analytical samples are
fractions separately. Therefore the precision and bias state-
collected and handled with careful regard to ensure that they
ments do not apply to analysis of water only.
are representative of the entire parcel. The crude oil or product
5.1.2.2 This method will typically quantify light alcohols
stream should be homogenous at the sampling point, and the
such as, (but not limited to), methanol and ethanol in the water
sample properly mixed prior to analysis. Sub-samples should
fraction, biasing the water result high.
not be allowed to settle prior to transfer into an analytical
5.1.2.3 Centrifuge tubes may be filled directly from a
device such as a centrifuge tube, distillation apparatus, or
sample tap and analyzed minimizing sample handling. Mini-
extraction thimble. Refer to API MPMS Chapter 8.1 (ASTM
mizing sample handling helps to maintain the representative
D4057) Standard Practice for Manual Sampling of Petroleum
nature of a sample.
and Petroleum Products, API MPMS Chapter 8.2 (ASTM
5.1.2.4 A 50 mL sample is used for analysis as measured in
D4177) Standard Practice for Automatic Sampling of Petro-
the centrifuge tube.
leum and Petroleum Products, API MPMS, and Chapter 8.3
5.1.2.5 The variety of acceptable solvents allows the user to
(ASTM D5854) Standard Practice for Mixing and Handling of
match the best solvent to the crude type. This can minimize
Liquid Samples of Petroleum and Petroleum Products for
bias resulting from precipitated material (asphaltenes or paraf-
appropriate sample collection and mixing.
fins) being measured as sediment.
4.3 It is imperative that every sample is mixed sufficiently to 5.1.2.6 This method will not measure dissolved water, thus
ensure that it is homogeneous. However, with prolonged the results may be biased low in crudes with dissolved water.
mixing the temperature of the sample will increase. This will In addition, depending upon the efficiency of the emulsion
decrease the representative nature of the sample due to breaker used, some highly stable emulsions may not fully
evaporative losses. The mixing system must be evaluated to break down which will bias the results low.
D7829 − 13 (2018)
5.1.2.7 The sensitivity of this method is limited to the 5.3.2.1 This test method may be appropriate for crude oils
divisions marked on centrifuge tubes. The intervals range from and products which contain light alcohols such as, but not
0.025 % to 12.5 % by volume of sediment and water. limited to, methanol and ethanol. However, no samples con-
5.1.2.8 The method is not highly prescriptive, and lack of taining alcohols were used in the round robin study; conse-
consistency may be a source of variability in the results. quently the precision and bias statements in the test method do
5.1.2.9 Because the user reads the result directly off the not apply.
glassware, result interpretation is susceptible to human error.
5.3.2.2 Mercaptans in crude oils will bias the results high.
5.1.2.10 Because this method is often performed in an
This interference is limited with the use of pyridine free
uncontrolled environment, maintaining “stoppered” tubes
reagents. The titration speed and sensitivity settings on Karl
throughout the entire analytical process may help maintain the
Fischer units may also mitigate the interference. Refer to the
representative nature of the sample.
method for information about mercaptan bias.
5.2 MPMS Chapter 10.2 (ASTM D4006, IP 358/82), Stan- 5.3.2.3 This test method allows the user flexibility with
implementation, the lack of consistency may be a source of
dard Test Method for Water in Crude Oil by Distillation:
5.2.1 Range of Application: variability in the results.
5.2.1.1 The scope of this test method does not indicate a
5.3.2.4 Syringes of sample may be drawn directly from the
range of water content. The round robin, upon which the
sample vessel of they may be drawn from a subsample
precision and bias statement was developed, ranged from 0.1 %
container. The syringe contents are then transferred to the
to 1 % water by volume.
titration vessel. The use of a subsample container and the
5.2.1.2 The practical minimum detection limit is 0.025 % by
syringe are a source of error.
volume. Lower concentrations of sediment and water should be
5.3.2.5 The analytical sample size is 1 g to 5 g of crude oil.
reported as less than 0.025 % v/v or 0 % v/v.
5.3.2.6 The resolution for this test method is in the nearest
5.2.2 Interferences, Biases, and Limitations:
hundredth 0.08 mass % for relatively dry crude up to the
5.2.2.1 This test method will typically quantify light alco-
nearest 0.4 mass % for wetter crude oils.
hols such as, but not limited to, methanol and ethanol in the
5.3.2.7 This repeatability for this test method ranges from
water fraction, biasing the water result high.
0.012 for 0.05 mass % of water to 0.040 mass % for 2.0 mass
5.2.2.2 Volumetric glassware may be filled directly from a
% of water.
sample tap. The volumetric glassware is rinsed with multiple
5.3.2.8 Due to the non-prescriptive flexibility in selection of
portions of solvent to ensure full transference of sample into
solvents and titration parameters, the potentiometric Karl
the distillation apparatus. This helps ensure that sample did not
Fischer method may have greater interference from mercaptans
settle prior to collection of analytical portions. If the sample is
than the coulometric method.
allowed to settle, the representative nature may be in question.
5.3.2.9 Samples and aliquots in secondary containers, which
5.2.2.3 Samples used for analysis range from 5 g to 200 g or
includes syringes, may stratify over time and bias the results.
mL, with the smaller sample used for crude oils containing a
higher water content. 5.3.2.10 This test method requires weighing the sample, but
5.2.2.4 The sensitivity of this test method is limited to the does not include a balance as required equipment.
divisions marked on the distillation trap. The intervals range
5.3.2.11 This test method allows manual titration using
from 0.125 % to 0.5 % water by volume. The intervals increase
Karl-Fischer reagent. Because the user reads the result directly
as the water content of the crude oil increases.
off the glassware, result interpretation is susceptible to human
5.2.2.5 The repeatability for this test method ranges fr
...
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.
´1
Designation: D7829 − 13 D7829 − 13 (Reapproved 2018)
Manual of Petroleum Measurement Standards (MPMS), Technical Report 2573
Standard Guide for
Sediment and Water Determination in Crude Oil
This standard is issued under the fixed designation D7829; 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.
ε NOTE—API information was added editorially in September 2013.
1. Scope
1.1 This guide covers a summary of the water and sediment determination methods from the API MPMS Chapter 10 for crude
oils. The purpose of this guide is to provide a quick reference to these methodologies such that the reader can make the appropriate
decision regarding which method to use based on the associated benefits, uses, drawbacks and limitations.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.4 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. Referenced Documents
2.1 ASTM Standards:
D473 Test Method for Sediment in Crude Oils and Fuel Oils by the Extraction Method (API MPMS Chapter 10.1)
D4006 Test Method for Water in Crude Oil by Distillation (API MPMSChapter 10.2)
D4007 Test Method for Water and Sediment in Crude Oil by the Centrifuge Method (Laboratory Procedure) (API MPMS
Chapter 10.3)
D4057 Practice for Manual Sampling of Petroleum and Petroleum Products (API MPMS Chapter 8.1)
D4177 Practice for Automatic Sampling of Petroleum and Petroleum Products (API MPMS Chapter 8.2)
D4377 Test Method for Water in Crude Oils by Potentiometric Karl Fischer Titration
D4807 Test Method for Sediment in Crude Oil by Membrane Filtration
D4928 Test Method for Water in Crude Oils by Coulometric Karl Fischer Titration
D5854 Practice for Mixing and Handling of Liquid Samples of Petroleum and Petroleum Products (API MPMS Chapter 8.3)
2.2 API Standards:
API MPMS Chapter 8.1 Standard Practice for Manual Sampling of Petroleum and Petroleum Products (ASTM D4057)
API MPMS Chapter 8.2 Standard Practice for Automatic Sampling of Petroleum and Petroleum Products (ASTM D4177)
API MPMS Chapter 8.3 Standard Practice for Mixing and Handling of Liquid Samples of Petroleum and Petroleum Products
(ASTM D5854)
MPMS Chapter 10.1 Standard Test Method for Sediment in Crude Oils and Fuel Oils by the Extraction Method (ASTM D473)
MPMS Chapter 10.2 Standard Test Method for Water in Crude Oil by Distillation (ASTM D4006)
This guide is under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and the API Committee on Petroleum Measurement,
and is the direct responsibility of Subcommittee D02.02 /COMQ,/COMQ the joint ASTM-API Committee on Hydrocarbon Measurement for Custody Transfer (Joint
ASTM-API). This guide has been approved by the sponsoring committees and accepted by the Cooperating Societies in accordance with established procedures. This practice
was issued as a joint ASTM-API standard in 2013.
Current edition approved May 1, 2013Oct. 1, 2018. Published July 2013November 2018. Originally approved in 2013. Last previous edition approved in 2013 as
ɛ1
D7829 – 13 . DOI: 10.1520/D7829-13E01.10.1520/D7829-13R18.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Available from American Petroleum Institute (API), 1220 L. St., NW, Washington, DC 20005-4070, http://www.api.org.
© Jointly copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, USA and the American Petroleum Institute (API), 1220 L Street NW, Washington DC 20005, USA
D7829 − 13 (2018)
MPMS Chapter 10.3 Standard Test Method for Water and Sediment in Crude Oil by the Centrifuge Method (Laboratory
Procedure) (ASTM D4007)
MPMS Chapter 10.4 Determination of Water and/or Sediment in Crude Oil by the Centrifuge Method (Field Procedure)
MPMS Chapter 10.7 Standard Test Method for Water in Crude Oils by Potentiometric Karl Fischer Titration (D4377)
MPMS Chapter 10.8 Standard Test Method for Sediment in Crude Oil by Membrane Filtration (D4807)
MPMS Chapter 10.9 Standard Test Method for Water in Crude Oils by Coulometric Karl Fischer Titration (D4928)
3. Significance and Use
3.1 Theoretically, all of the sediment and water determination methods are valid for crude oils containing from 00 % to 100 %
by volume sediment and water; the range of application is specified within the scope of each method. The round robins for all
methods were conducted on relatively dry oil. All precision and bias statements included in the methods are based upon the round
robin data. Analysis becomes more challenging with crude oils containing higher water contents due to the difficulty in obtaining
a representative sample, and maintaining the sample quality until analysis begins.
3.2 Currently, Karl Fischer is generally used for dry crude oils containing less than 5 % water. Distillation is most commonly
used for dry and wet crude oils and where separate sediment analysis is available or in situations where the sediment result is not
significant. The laboratory centrifuge methods allow for determination of total sediment and water in a single analysis. The field
centrifuge method is used when access to controlled laboratory conditions are not available.
3.3 In the event of a dispute with regard to sediment and water content, contracting parties may refer to the technical
specifications table to determine the most appropriate referee method based upon knowledge of and experience with the crude oil
or product stream.
4. Procedure
4.1 To obtain the total sediment and water results when the two are determined by separate methods: First, add the raw,
unrounded results together, and then round the sum to the correct significant figure.
4.2 It is critically important that the analytical samples are collected and handled with careful regard to ensure that they are
representative of the entire parcel. The crude oil or product stream should be homogenous at the sampling point, and the sample
properly mixed prior to analysis. Sub-samples should not be allowed to settle prior to transfer into an analytical device such as
a centrifuge tube, distillation apparatus, or extraction thimble. Refer to API MPMS Chapter 8.1 (ASTM D4057) Standard Practice
for Manual Sampling of Petroleum and Petroleum Products, API MPMS Chapter 8.2 (ASTM D4177) Standard Practice for
Automatic Sampling of Petroleum and Petroleum Products, API MPMS, and Chapter 8.3 (ASTM D5854) Standard Practice for
Mixing and Handling of Liquid Samples of Petroleum and Petroleum Products for appropriate sample collection and mixing.
4.3 It is imperative that every sample is mixed sufficiently to ensure that it is homogeneous. However, with prolonged mixing
the temperature of the sample will increase. This will decrease the representative nature of the sample due to evaporative losses.
The mixing system must be evaluated to determine that the mixing time is sufficient without undue temperature increases.
4.4 Sampling error can be a source of bias in analytical methods. This is reflected in the precision and bias statement for each
method, but it should be considered when evaluating methods. A larger sample size will increase the probability that a sample is
representative of the entire parcel and can minimize the potential bias arising from a less homogenous sample stream. Measuring
sample size by weight using an analytical balance is not subject to human error; measuring sample size by volume using analytical
glassware is a source of human error.
4.5 When sample size is determined by weight, consider the type of analytical balance used to weigh the sample. Ensure that
the resolution is appropriate, having sufficient significant figures, for the analysis.
5. Report
Water Only Determination Methods
5.1 MPMS Chapter 10.4, Determination of Water and/or Sediment in Crude Oil by the Centrifuge Method (Field Procedure):
NOTE 1—ASTM Test Methods D96 for Water and Sediment in Crude Oil By Centrifuge (Field Procedure), the technically equivalent ASTM standard
was withdrawn without replacement in 2000.
5.1.1 Range of Application:
5.1.1.1 There is no approved precision and bias statement for this method.
5.1.1.2 The practical minimum detection limit is 0.025 % v/v water. Lower concentrations of water should be reported as less
than 0.025 % v/v or 0 % v/v.
5.1.1.3 This scope of the method indicates that it applies to crude oil, there is no water content specified in the scope.
5.1.2 Interferences, Biases, and Limitations:
5.1.2.1 The round robin for this method was conducted for combined sediment and water, not the sediment or water fractions
separately. Therefore the precision and bias statements do not apply to analysis of water only.
D7829 − 13 (2018)
5.1.2.2 This method will typically quantify light alcohols such as, (but not limited to), methanol and ethanol in the water
fraction, biasing the water result high.
5.1.2.3 Centrifuge tubes may be filled directly from a sample tap and analyzed minimizing sample handling. Minimizing sample
handling helps to maintain the representative nature of a sample.
5.1.2.4 A 50 mL sample is used for analysis as measured in the centrifuge tube.
5.1.2.5 The variety of acceptable solvents allows the user to match the best solvent to the crude type. This can minimize bias
resulting from precipitated material (asphaltenes or paraffins) being measured as sediment.
5.1.2.6 This method will not measure dissolved water, thus the results may be biased low in crudes with dissolved water. In
addition, depending upon the efficiency of the emulsion breaker used, some highly stable emulsions may not fully break down
which will bias the results low.
5.1.2.7 The sensitivity of this method is limited to the divisions marked on centrifuge tubes. The intervals range from 0.025 %
to 12.5 % by volume of sediment and water.
5.1.2.8 The method is not highly prescriptive, and lack of consistency may be a source of variability in the results.
5.1.2.9 Because the user reads the result directly off the glassware, result interpretation is susceptible to human error.
5.1.2.10 Because this method is often performed in an uncontrolled environment, maintaining “stoppered” tubes throughout the
entire analytical process may help maintain the representative nature of the sample.
5.2 MPMS Chapter 10.2 (ASTM D4006, IP 358/82), Standard Test Method for Water in Crude Oil by Distillation:
5.2.1 Range of Application:
5.2.1.1 The scope of this test method does not indicate a range of water content. The round robin, upon which the precision and
bias statement was developed, ranged from 0.1 % to 1 % water by volume.
5.2.1.2 The practical minimum detection limit is 0.025 % by volume. Lower concentrations of sediment and water should be
reported as less than 0.025 % v/v or 0 % v/v.
5.2.2 Interferences, Biases, and Limitations:
5.2.2.1 This test method will typically quantify light alcohols such as, but not limited to, methanol and ethanol in the water
fraction, biasing the water result high.
5.2.2.2 Volumetric glassware may be filled directly from a sample tap. The volumetric glassware is rinsed with multiple portions
of solvent to ensure full transference of sample into the distillation apparatus. This helps ensure that sample did not settle prior
to collection of analytical portions. If the sample is allowed to settle, the representative nature may be in question.
5.2.2.3 Samples used for analysis range from 55 g to 200 g 200 g or mL, with the smaller sample used for crude oils containing
a higher water content.
5.2.2.4 The sensitivity of this test method is limited to the divisions marked on the distillation trap. The intervals range from
0.125 % to 0.5 % water by volume. The intervals increase as the water content of the crude oil increases.
5.2.2.5 The repeatability for this test method ranges from 0.017 for 0.005 volume % of water to 0.08 for 0.130 volume % of
water.
5.2.2.6 This test method is more time consuming than the centrifuge or Karl Fischer methods.
5.2.2.7 This test method requires a laboratory environment to set up and operate.
5.2.2.8 Because the user reads the result directly off the glassware, result interpretation is susceptible to human error.
5.3 MPMS Chapter 10.7 (ASTM D4377-00, IP 356/99), Standard Test Method for Water in Crude Oils by Potentiometric Karl
Fischer Titration:
5.3.1 Range of Application:
5.3.1.1 The scope of this test method applies to crude oils containing 0.02 to 2 mass or volume % of water.
5.3.1.2 The average practical minimum detection limit for this method is 0.08 mass %. This is based upon oil with a relative
density of 0.850 and a water equivalence of 4 for the titration.
5.3.2 Interferences, Biases, and Limitations:
5.3.2.1 This test method may be appropriate for crude oils and products which contain light alcohols such as, but not limited
to, methanol and ethanol. However, no samples containing alcohols were used in the round robin study; consequently the precision
and bias statements in the test method do not apply.
5.3.2.2 Mercaptans in crude oils will bias the results high. This interference is limited with the use of pyridine free reagents.
The titration speed and sensitivity settings on Karl Fischer units may also mitigate the interference. Refer to the method for
information about mercaptan bias.
5.3.2.3 This test method allows the user flexibility with implementation, the lack of consistency may be a source of variability
in the results
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