Organic-geochemical characterization and correlation of crude oils samples from the most significant oil fields in the Sirte basin, Lybia
Organsko-geohemijska karakterizacija i korelacija uzoraka sirove nafte iz najznačajnijih naftnih polja basena Sirte, Libija
Докторанд
Faraj, Musbah Abduljalil M.Ментор
Jovančićević, BranimirЧланови комисије
Šolević-Knudsen, TatjanaStojanović, Ksenija
Метаподаци
Приказ свих података о дисертацијиСажетак
Ova doktorska disertacija sastoji se od dve jasno definisane celine.
U prvom delu ove teze vrednosti parametara izračunatih na osnovu raspodela i obilnosti
odabranih pentacikličnih terpana u sirovim naftama iz Libije i Srbije, koji su originalno dobijeni
iz rezultata gasno hromatografsko – maseno spektrometrijske (GC-MS) analize upoređene su sa
kvantifikacionim rezultatima koji su zasnovani na gasno hromatografsko – maseno
spektrometrijsko – maseno spektrometrijskoj (GC-MS-MS) analizi. Analizirani parametri su
najčešće korišćeni terpanski izvorni i maturacioni parametri, koji su primenjeni na veliku grupu
uzoraka od 70 sirovih nafti, koje potiču iz pet naftnih polja. Cilj je bio da se ispita u kojoj meri se
merenja odabranih parametara ovim dvema tehnikama slažu i da se odredi uticaj razlika između
vrednosti ovih parametara na geohemijsku interpretaciju. U tom cilju, korišćene su dve
statističke metode: koeficijent slaganja korelacija i dijagram srednja vrednost-razlika. Dobijeni
rezul...tati pokazuju da izračunavanje C2718α(H)-22,29,30-trisnorneohopan/(C2718α(H)-22,29,30-
trisnorneohopan + C2717α(H)-22,29,30- trisnorhopan), C2918α(H)-30-
norneohopan/C2917α(H)21β(H)-30-norhopan i C2917α(H)21β(H)-30- norhopan
/C3017α(H)21β(H)- hopan odnosa bilo GC-MS ili GC-MS-MS tehnikom ne utiče značajno na
interpretaciju. S druge strane, određivanje C3017β(H)21α(H)-moretan/C3017α(H)21β(H)-hopan
odnosa, gamaceranskog indeksa i oleananskog indeksa GC-MS ili GC-MS-MS tehnikom može
značajno uticati na interpretaciju. Ove razlike se mogu objasniti koeluiranjem i preklapanjem
pikova tokom GC-MS analize ali takođe i boljim razdvajanjem, većom preciznošću i boljom
selektivnošću GC-MS-MS tehnike. Odstupanje skoro svih parametara od linije jednakosti je
slično za nafte iz istog naftnog polja ali su uočene razlike pri analizi nafti iz različitih naftnih
polja. Stoga, kada se planira primena GC-MS-MS rezultata u organsko geohemijskim
interpretacijama, preporučuje se i regionalna kalibracija odnosa između GC-MS i GC-MS-MS rezultata za svaki naftni sistem...
This thesis consists of two dinstictive parts.
In the first part of this thesis the values of parameters calculated from distributions and
abundances of selected pentacyclic terpanes in crude oils from Libya and Serbia, which were
originally derived from gas chromatography-mass spectrometry (GC-MS) were compared with
quantification results based on gas chromatography-mass spectrometry-mass spectrometry (GCMS-
MS). The parameters analyzed are the most often used terpane source and maturity
parameters, which were applied to a large sample set of 70 oils, originating from five oil fields.
The aim of the paper was to investigate to which extent the measurements of the selected
parameters by these two instrumental techniques agree and to determine influence of differences
between parameter values on geochemical interpretation. For that purpose two methods,
concordance correlation coefficient and mean-difference plot were used. The obtained results
indicate that calculation of C2718α(H)-22,2...9,30-trisnorneohopane/(C2718α(H)-22,29,30-
trisnorneohopane + C2717α(H)-22,29,30-trisnorhopane), C2918α(H)-30-
norneohopane/C2917α(H)21β(H)-30-norhopane and C2917α(H)21β(H)-30-
norhopane/C3017α(H)21β(H)-hopane ratios either by GC-MS or GC-MS-MS do not
significantly influence interpretation. On the other hand, determination of C3017β(H)21α(H)-
moretane/C3017α(H)21β(H)- -hopane ratio, gammacerane index and oleanane index by GC-MS
vs. GC-MS-MS could notably affect interpretation. These differences can be explained by coelution
and peak overlapping in GC-MS but also by better separation, higher precision and better
selectivity of the GC-MS-MS. Deviation of the almost all studied parameters from the line of
equality was similar for the oils from the same oil field but some differences were observed for
the oils from different oil fields. Therefore, when GC-MS-MS results are to be used in organic
geochemical interpretations, a regional calibration of GC-MS vs. GC-MS-MS relationship for
each petroleum system is highly recommended...