ASTM D7708-11

Standard Test Method for Microscopical Determination of the Reflectance of Vitrinite Dispersed in Sedimentary Rocks

SIGNIFICANCE AND USE
The mean reflectance of the vitrinite maceral in sedimentary rocks as determined by this test method is used as an indicator of thermal maturity, that is, the progressive geochemical alteration of dispersed organic material experienced during diagenesis, catagenesis, and metagenesis. In the case of hydrocarbon source rocks, three major categories of thermal maturity are defined by vitrinite reflectance: immature (Roran ≤ 0.5%), mature (Roran ≈ 0.5-1.35%), and overmature (Roran ≥ 1.35%) with respect to the generation of liquid hydrocarbons. Thermal maturity as determined by the reflectance of vitrinite dispersed in sedimentary rocks is similar to the rank classification of coals as presented in Classification D388 and measured similarly to the reflectance of vitrinite in coal as presented in Test Method D2798. The mean reflectance of the vitrinite maceral in sedimentary rocks correlates with geochemically determined parameters of thermal maturity and can be used to characterize thermal maturation history, to calibrate burial history models, and to better understand the processes of hydrocarbon generation, migration, and accumulation in conventional and unconventional petroleum systems.
SCOPE
1.1 This test method covers the microscopical determination of the reflectance measured in oil of polished surfaces of vitrinite dispersed in sedimentary rocks. This test method can also be used to determine the reflectance of macerals other than vitrinite dispersed in sedimentary rocks.
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 and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 31-Mar-2011
• ICS: 91.100.15 - Mineral materials and products
• Technical Committee: D05 - Coal and Coke
• Drafting Committee: D05.28 - Petrographic Analysis of Coal and Coke

Standards Content (Sample)

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Designation:D7708 −11
StandardTest Method for
Microscopical Determination of the Reflectance of Vitrinite
1
Dispersed in Sedimentary Rocks
This standard is issued under the fixed designation D7708; 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 3.3.1 alginite, n—a liptinite maceral occurring in structured
morphologies, telalginite, and unstructured morphologies, la-
1.1 This test method covers the microscopical determination
malginite.
of the reflectance measured in oil of polished surfaces of
3.3.2 bituminite, n—an amorphous primary liptinite maceral
vitrinite dispersed in sedimentary rocks. This test method can
with low reflectance, occasionally characterized by colored
also be used to determine the reflectance of macerals other than
internal reflections and weak orange-brown fluorescence, de-
vitrinite dispersed in sedimentary rocks.
rived from bacterial biomass and the bacterial decomposition
1.2 The values stated in SI units are to be regarded as
of algal material and faunal plankton. Bituminite is equivalent
standard. No other units of measurement are included in this
to the amorphous organic matter recognized in strew slides of
standard.
3
concentrated kerogen (1).
1.3 This standard does not purport to address all of the
3.3.2.1 Discussion—Bituminite may be distinguished from
safety concerns, if any, associated with its use. It is the
vitrinite by lower reflectance, as well as higher fluorescence
responsibility of the user of this standard to establish appro-
intensity if fluorescence is present in vitrinite. Bituminite has
priate safety and health practices and determine the applica-
poorly-defined wispy boundaries and may be speckled or
bility of regulatory limitations prior to use.
unevenly colored whereas vitrinite has distinct boundaries and
is blockier and evenly colored. The occurrence of bituminite in
2. Referenced Documents
association with lamalginite and micrinite is common. Rock
2
2.1 ASTM Standards:
type, thermal maturity, and geologic occurrence can be used to
D121 Terminology of Coal and Coke
interpret the potential presence of bituminite; for example,
D388 Classification of Coals by Rank
bituminite may be expected to occur in lacustrine or marine
D2797 Practice for Preparing Coal Samples for Microscopi-
settings. It is less commonly present in fluvial or similar
cal Analysis by Reflected Light
proximal depositional environments, where vitrinite may be
D2798 Test Method for Microscopical Determination of the expected to occur in greater abundance.
Vitrinite Reflectance of Coal
3.3.3 chitinozoan, n—a group of flask-shaped, sometimes
ornamented marine microfossils of presumed metazoan origin
3. Terminology
which are composed of ’pseudochitin’ proteinic material and
3.1 Definitions—For definitions of terms, refer to Terminol-
which occur individually or in chains. Chitinozoan cell walls
ogy D121.
are thin, opaque to translucent, and range from dark gray to
white in reflected white light similar to vitrinite. Chitinozoans
3.2 Abbreviations:
are common in Ordovician to Devonian marine shales.
3.2.1 R ran—mean random reflectance measured in oil.
o
Other organizations may use other abbreviations for mean
3.3.4 conodont, n—the phosphatic, tooth-like remains of
random reflectance.
marine vertebrate worm-like animals present from the Cam-
brian through Triassic, composed predominantly of apatite
3.3 Definitions of Terms Specific to This Standard:
with subordinate amounts of organic matter. Conodont mor-
phology is variable, but often well-defined denticles and blades
1
This test method is under the jurisdiction of ASTM Committee D05 on Coal
are preserved. In reflected white light examination conodonts
and Coke and is the direct responsibility of Subcommittee D05.28 on Petrographic
range from pale yellow to light brown to dark brown and to
Analysis of Coal and Coke.
black.
Current edition approved April 1, 2011. Published April 2011. DOI: 10.1520/
D7708–11.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
3
Standards volume information, refer to the standard’s Document Summary page on The boldface numbers in parentheses refer to a list of references at the end of
the ASTM website. this standard.
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D7708−11
3.3.5 fusinite, n—an inertinite maceral distinguished princi- 3.3.13 maceral, n—an organic component occurring in sedi-
pally by
...