Organsko-geohemijski pristupi u definisanju zone generisanja nafte u panonskom basenu Srbije
Organic-geochemical approaches in defining oil generation zone in the pannonian basin in Serbia
Author
Stojadinović, Sanja M.Mentor
Stojanović, KsenijaCommittee members
Kostić, AleksandarJovančićević, Branimir
Šajnović, Aleksandra
Metadata
Show full item recordAbstract
Tokom rada na disertaciji ispitivana su 33 uzorka mogućih matičnih
stena iz tri najznačajnije lokalne generativne depresije našeg dela Panonskog
basena: Banatsko Aranđelovo, Srpska Crnja i Zrenjanin. Devet ispitivanih
uzoraka je bilo iz srednjeg miocena (baden i sarmat), 16 uzoraka je iz gornjeg
miocena (panon i pont), sedam uzoraka iz nedefinisanog miocena (srednji
miocen ili panon) i jedan uzorak je nepoznate stratigrafske pripadnosti. Uzorci
potiču sa relativnih dubina od 1540 do 3420 m, na kojima temperature iznose
88-175 °C. Ispitivano područje se odlikuje specifičnim geotermičkim
karakteristikama: povišenim geotermalnim gradijentom (4,0 – 7,5 °C/100m),
toplotnim tokovima visokog intenziteta (90 – 110 mW/m2) i veoma velikim
brzinama zagrevanja sedimenata srednjeg i gornjeg miocena (9 – 22 °C/milion
godina).
Osnovni predmet disertacije bio je definisanje zone generisanja nafte u
Panonskom basenu Srbije, odnosno definisanje „naftnog prozora” na osnovu
detaljnih geohemijskih istraživ...anja u kombinaciji sa već poznatim geološkim
podacima. Ciljevi ove teze bili su i utvrđivanje porekla, sredine taloženja i
zrelosti organske supstance ispitivanih matičnih stena, kao i utvrđivanje
primenljivosti maturacionih parametara i jednačina za izračunavanje refleksije
vitrinita za uzorke matičnih stena iz hipertermalnog basena. Na osnovu
korelacije biomarkerskih parametara procenjena je i starost za sedam uzoraka iz
nedefinisanog miocena.
Opšta karakterizacija organske supstance podrazumevala je elementarnu
analizu i Rock-Eval pirolizu, a refleksija vitrinita je korišćena za utvrđivanje
Izvod
ii
stepena zrelosti kerogena. Rastvorna organska supstanca je izolovana
ekstrakcijom po Soksletu (Soxhlet), a zatim je razdvojena na ugljovodonični deo
i polarni ostatak. Za analizu individualnih biomarkera (n-alkani, izoprenoidni
alifatični alkani, sterani i terpani) i aromatičnih jedinjenja (derivati naftalena,
fenantrena i dibenzotiofena) primenjene su savremene instrumentalne metode
gasna hromatografija sa masenom spektrometrijom (GC-MS) i gasna
hromatografija sa tandemskom masenom spektrometrijom (GC-MS-MS).
Organska supstanca je mešovitog drvenasto-algalnog porekla, pretežno
sačinjena od kerogena tipa II. Taloženje organske supstance se odvijalo u
promenljivim uslovima, od redukcionih do suboksičnih, pri čemu se salinitet
paleosredine postepeno smanjivao od srednjeg ka gornjem miocenu.
Početak generisanja nafte odgovara temperaturi 110-120 °C i dubini od
1850 do 2100 m, pri refleksiji vitrinita, Rc ≈ 0,53-0,58 %. „Naftni prozor“ dostiže
maksimum na oko 145-150 °C, pri Rc ≈ 0,72-0,75 %, na dubinama od 2600 do
2900 m. Kraj „naftnog prozora“ je na 170-175 °C, pri Rc ≈ 0,89-0,93 %, i dubini
od oko 3500 m. Izvedena je i aproksimativna kalibracija vrednosti
biomarkerskih maturacionih parametara u odnosu na „naftni prozor“. Pri tome
je definisana i moguća primena dva, u organsko-geohemijskoj literaturi,
relativno nova biomarkera, „rano eluirajućih“ hopana (čija struktura je
pretpostavljena, ali ne i u potpunosti potvrđena) i C(14a)-homo-nor-17α(H)-
hopana.
Kada je reč o primenljivosti maturacionih parametara i jednačina za
izračunavanje refleksije vitrinita na uzorcima matičnih stena iz hipertermalnog
basena ustanovljeno je da su najprimenljivije jednačine zasnovane na
savremenoj temperaturi, steranskim i dibenzotiofenskim maturacionim
parametrima i maturacionom parametru predloženom u ovoj disertaciji koji
predstavlja odnos C(14a)-homo-nor-17α(H)-hopana i C30 17α(H),21β(H)-hopana.
Takođe, po prvi put su ustanovljene linearna i logaritamska jednačina koje
povezuju refleksiju vitrinita sa vrednostima steranskog maturacionog
parametra C29ββ(R)/C29(ββ(R)+αα(R)).
In this thesis 33 samples of potential source rocks taken from three most
important local generative depressions in the Serbian part of the Pannonian
Basin, Banatsko Aranđelovo, Srpska Crnja and Zrenjanin were investigated.
Nine samples were from Middle Miocene (Badenian and Sarmatian), 16 were
from Upper Miocene (Pannonian and Pontian), 7 samples were from undefined
Miocene (Middle Miocene or Pannonian) and for one sample age was
unknown. Samples were taken from relative depths from 1540 to 3420 m at
which subsurface temperatures ranges from 88 to 175 °C, respectively. The
investigated area is characterized by specific geotermal characteristics: high
geothermal gradients (4.0 – 7.5 °C/100m), high heat flow (90 – 110 mW/m2) and
the exceptionally high heating rate of Middle and Upper Miocene sediments (9
– 22 °C/Ma).
The main objective of this thesis was to determine oil generation zone in
the Pannonian Basin in Serbia, i.e. to define “oil window” based on
comprehensive geochemical rese...arch in combination with already known
geological data. The goals of this thesis were to determine the origin,
depositional environment and maturity of organic matter of investigated source
rocks, as well as applicability of maturation parameters and equations for
calculation of vitrinite reflectance for source rocks’ samples from a
hyperthermal basen. The age of seven samples from undefined Miocene was
estimated based on correlation of biomarker parameters.
General characterisation of organic matter was done by elemental
analysis and Rock-Eval pyrolysis, whereas vitrinite reflectance was used for
Abstract
v
determination of kerogen maturity. The extractable organic matter was isolated
using the Soxhlet method and then it was separated into hydrocarbons and
polar residue. For analysis of individual biomarkers (n-alkanes, isoprenoid
aliphatic alkanes, steranes and terpanes) and aromatic compounds (derivatives
of naphthalene, phenanthrene and dibenzothiophene) the modern instrumental
techniques, gas chromatography-mass spectrometry (GC-MS) and gas
chromatography-tandem mass spectrometry (GC-MS-MS) were used.
The organic matter is of mixed woody-algal origin and consists
predominantly of Type II kerogen. Organic matter was deposited under
variable conditions from reducing to sub-oxic. Salinity of the
palaeoenvironment gradualy decreased from Middle to Upper Miocene.
The oil generation begins at the temperature of 110-120 °C and % Rc ≈
0.53-0.58 %, “oil window” peaks at ca. 145-150 oC and % Rc ≈ 0.72-0.75 %, and it
ends at 170-175 °C and % Rc ≈ 0.89-0.93 %, which corresponds to the relative
depths of 1850–2100 m, 2600–2900 m and ca. 3500 m, respectively. An
approximate calibration of the values of biomarker ratios relative to “oil
window” was proposed. The possible applicability of two relatively novel
biomarkers in organic geochemical literature “early eluting hopanes“, which
structure is proposed - but not entirely proven, and C(14a)-homo-nor-17α(H)-
hopane was established.
Concerning the applicability of maturity parameters and equations for
calculation of vitrinite reflectance for the source rocks’ samples from a
hyperthermal basin, the obtained results indicated that the most relevant are
equations based on maximal palaeotemperature, sterane and dibenzothiophene
maturity parameters and maturity parameter proposed in this thesis, which
represents the ratio of C(14a)-homo-nor-17α(H)-hopane and C30 17α(H),21β(H)-
hopane. Also, linear and logarithmic equations, connecting vitrinite reflectance
and values of the sterane maturity parameter, C29ββ(R)/C29(ββ(R)+αα(R)), have
been established for the first time.
Faculty:
Универзитет у Београду, Хемијски факултетDate:
31-08-2016Projects:
- Geochemical investigations of sedimentary rocks - fossil fuels and environmental pollutants (RS-176006)