istván dunkl sedimentology, university of göttingen · caving mud additives subtypes vary ro (

Beckenanalyse 2:Analytic tools for basin analysis: thermometers and geochronometers [M.Geo.136b]

Part 2a: How to measure the paleo-tempearture? (by organic methods)

István DunklSedimentology, University of Göttingen

http://www.sediment.uni-goettingen.de/staff/dunkl/

1) Heat flow in basins2) Geothermometry in basins by: vitrinite-, bitumen-, graptolite reflectance,

Raman spectroscopy, conodont alteration index, spore colour, fluorescence, Rock-Eval, molecular ratios, clay mineralogy ...

3) Fission track thermochronology (nuclear physics, statistics)4) Dating volcanic events (= formation ages) and

basement exhumation (= cooling ages)5) Complex thermal histories of basins & thermal modelling6) Detrital geochronology (provenance by single-grain ages)

7) (U-Th)/He thermochronology8) K/Ar, Ar/Ar, Luminescence, ESR and cosmogenic dating of sediments9) U-Pb and U-series dating of sediments

University of Göttingen

SOURCE ROCKmostly fine clay with more than 0.5% kerogene

RESERVOIR ROCKporous and permeable as required for production

SEAL - CAP ROCKimpermeable cover of the reservoir

TRAPgeometric ordening of source rock /reservoir/seal

MATURATIONtime and temperature

CONDUITpermeable migration path from source rock to trap

TIMINGtrap needs to be present at the time of migration

Hydrocarbon – fundamental conditions for economic hydrocarbon accumulation

... in this temperature? only the grass grows ...

Geothermometry - organic-based method groups

Zeolite mineralogy

Two-carbonate thermometry

Illite – smectitite "thermometry"

Illite "crystallinity" (IC, Kübler index)

b0-parameter

Chlorite "crystallinity"

Fluid inclusion

Optical

Chemical

Molecular

Isotope

Geothermometry - inorganic bench-marks

Thermometry – organic bench-marksVitrinite reflectance (Ro) Vitrinite is a maceral in coal and organic particles derived from land plants since Silurian. With increasing thermal stress, the reflectance value of vitrinite maceralincreases.

Graptolite reflectance

Raman spectroscopy

Thermal Alteration Index (TAI) The darkening of kerogen particles with increasing thermal maturity can be used as an indicator of maturity. In order to minimize differences in color caused by changes in the type or thickness of the kerogen particles, TAI measurements are carried out on bisaccate pollen grains whenever possible. If no pollen can be found, TAI values are estimated, with lower confidence, from amorphous kerogen.

Conodont Alteration Index (CAI) Colors of the specimens thus obtained are determined under a binocular microscope and compared with standards. Although conodonts are composed of carbonate apatite, changes in conodont color are apparently due to carbonization of inclusions of small amounts of organic matter during catagenesis and metagenesis.

Rock eval pyrolysis temperature (Tmax)

Carbon Preference Index (CPI) Immature rocks often had high CPI values (> 1.5), whereas those of oils were almost always below 1.2. However, the decrease in CPI with increasing maturity depends upon the type of organic matter originally present as well as on maturity. In particular, rocks deposited in pelagic environments, in which the input of terrestrial lipids was very limited, have low CPI values even when immature.

Vitrinite in microscope ( w: white light, f: fluorescence )

[Borrego et al., 2006]

Optical observation of organic material

[Diessel, 1992]

reflected

light

reflected

light

transmitted

light

UVfluorescence

Ordering and maturation of organic matter

[Taylor et al., 1998]

2 38U 20.000.00 01�-decay (Hegas)natura l fission

Temperature [°C]

H eliumorfiss iontrackage [Ma]

zonesensit

[Wol fetal., 1998

He-ageFT-ag e

Pr inciple Sens itivity

a patite

[Bustin et al., 1985]

Vitrinite Reflectance (%Ro) is a measurement of the percentage of light reflected off the vitrinite maceral in oil immersion.

Vertical trend of VR


Influence of heat flow on VR trend


[Laczó & Jámbor, 1986]

Primary and recycled vitrinitein a basin fill

VR --- interlaboratory comparison

[Borrego et al., 2006]

Bias on vitrinite reflectance

problem I: anisotropy

[Teichmüller & Teichmüller, 1981][Teichmüller & Teichmüller, 1984]


Temperature

[°C]


zonesensit

[Wol fetal., 1998

He-ageFT-ag e


a patite

[Cardott, 2012]

PROPERLY IDENTIFIED VITRINITE PrimaryRecycledCavingMud additives Subtypes vary Ro (<0.5)

FACTORS AFFECTING ACCURATE Ro MEASUREMENT Rough textured vitriniteWeatheredPartially dissolved (pitted) FracturedOxidized vitriniteInclusionsPyriteBitumenOther maceralsOily vitriniteNatural coking Too few readings (<20)

MATERIAL WHICH MAY LOOK LIKE VITRINITE Solid bitumen (several types) PseudovitriniteSemifusinite

Problems in obtaining true Ro maturities (major maceral types)

[Allen & Allen]

Bias of vitrinite reflectance II:

other maceral types

Maturation trends of the most common maceral types

Reflectance histograms indicating three vitrinite (or maceral!) populations

[Nzoussi-Mbassani et al.]

Typical vertical trends of organic maturation

Change in the trend of vitrinite reflectance ?

[Teichmüller & Teichmüller, 1968]

[Engel and Macko, 1993]

Typical trends?

Contouered vitrinite reflectance depth profile

[Vermeesch et al., 2006]

Estimation of the removed sediment thickness

[Bray et al., 1992]

What was the reason of the increased temperature?

[Bray et al., 1992]

?

[Feinstein et al., 1996]

Thermometry - vitrinite reflectance


[Suggate, 1998]

100°C/km70°C/km

50°C/km40°C/km

30°C/km

20°C/km

Dep

th [k

m]

Reflectance [%]Vitrinite reflectance depth profile

VR depth profiles from the Danish Basin (present day)

[Petersen et al., 2008]

VR depth profiles

(shale sonic velocity

corrected depth)

[Petersen et al., 2008]

Sonic velocity profile (a small excursion towards compaction indicators)

[Japsen et al., 2007]


Thermometry -

vitrinite reflectance

vs.

Burial diagenesis –

porosity

http://www.petrodynamics.com/Products/Simulators/Hydrocarbon/Html/ThermalConductivity.html

Vitrinite reflectance Temperature

Specific heatThermal conductivity

A real-life example --- excursion into the oil kitchen (Gulf of Mexico)

Time-temperature influence on vitrinite reflectance

VR is calibrated principally for diagenetic conditions

[Underwood et al., 1993]

TTI (an old, but logic method)

Principle of subsidence & maturation modelling

[Palumbo et al., 1999]

What is bitumen?

[Quick, 1998]

Mean vitrinite vs. bitumen reflectance

[Quick, 1998]

Geothermometry by bitumen reflectance

[Quick, 1998]

Geothermometry

Bitumen reflectance (can be 'compressively matured solid bitumen')

[Gao et al., 2001]

Geothermometry by graptolite reflectance

[Goodarzi and Norford, 1985]

CAI: conodont alteration index

[Königshof, 2003]

[Goodarzi and Norford, 1985]

Thermometry - conodont alteration index

[Ibrahim, 1996]

Spore colour index

[Matchette-Downes, 2009]

Transmitted light vs. UV light excitation of spores

Vitrinite reflectance (Ro) vs. spore colour index (SCI)

[Subroto et al., 2010]

Geothermometry

(other methods: e.g. fluorescence)

Thermometry - fluorescence vs. vitrinite reflectance

Fluorescence alteration curves for vitrinites

[Pickel et al., 2001]

FAMMTM (fluorescence alteration of multiple macerals)


FAMM (fluorescence alteration of multiple macerals)

!! modification by storage


Correlation of variousmaturationindicators for organic matter

[ICCP,Borrego, 2014]

Geothermometry -

Raman spectroscopy of

carbonaceous material

[Beyssac et al., 2004]

Geothermometry -

Raman spectroscopy

of carbonaceous

material



Geothermometry -

Raman spectroscopy

of carbonaceous

material


Temperature

[°C]


zonesensit

[Wol fetal., 1998

He-ageFT-ag e


a patite

[Lis et al., 2005]

Fourier transformation infra red spectroscopy (FTIR)


Temperature

[°C]


zonesensit

[Wol fetal., 1998

He-ageFT-ag e


a patite

[Lis et al., 2005]

Correlation of FTIR parameters and VR

Pyrolysis –

Example of rock eval trace. HC = hydrocarbon

[http://www-odp.tamu.edu/]

[Behar et al., 2001]

Rock-Eval: distinction of organic and mineral carbon


Hydrocarbon -maturation

[Behar et al., 2001]Major Rock-Eval parameters

Tmax is temperature at which maximum yield of hydrocarbons occurs during pyrolysis; S1 is integral of first peak (existing hydrocarbons volatized at 250°C for 5 minutes); S2 is integral of second peak (hydrocarbons produced by pyrolysis of solid organic matter between 250° and 550°C); S3 is integral of third peak (CO2 produced by pyrolysis of kerogen between 250° and 390°C); PI, production index (S1/S1+S2); TOC, total organic carbon; HI, hydrogen index (S2/TOC); OI, oxygen index (S3/TOC)

[Nuccio and Condon, 1996 / U.S. GEOLOGICAL SURVEY BULLETIN 2000–O]

Major Rock-Eval parameters

Calibration of Rock-Eval Tmax to VR

[Lee et al., 2010]


Maturation estimation by molecular ratios


Temperature

[°C]


zonesensit

[Wol fetal., 1998

He-ageFT-ag e


a patite

[Matchette-Downes, 2009]

Correlation between optical and hydrocarbon maturity indicators

[Lüders and Plessen, 2011]

Carbon isotope signature as indicator on the transformation temperature

[Lüders and Plessen, 2011]

Carbon isotope signature as indicator on the transformation temperature

istván dunkl sedimentology, university of göttingen · caving mud additives subtypes vary ro (

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