25th International Meeting on Organic Geochemistry IMOG 2011

P-026
Comparison of comprehensive two-dimensional gas
chromatography/time-of-flight mass spectrometry and gas
chromatography-mass spectrometry for calculating the
geochemical parameter
Huitong Wang 1,2,3 , Na Weng 1,2 , Shuichang Zhang 1,2,3
1 Petroleum Geology Research and Laboratory Center, Institute of Petroleum Exploration & Development,
PetroChina, Beijing, China, 2 Key Laboratory of Petroleum Geochemistry of PetroChina, Beijing, China,
3 State key laboratory of enhanced oil recovery, RIPED, PetroChina, Beijing, China (corresponding
author:wanght@petrochina.com.cn)
In this paper, comprehensive two-dimensional gas
chromatography / time-of-flight mass spectrometry
and gas chromatography-mass spectrometry are
applied respectively to analyze saturated and
aromatic hydrocarbons of crude oil, moreover,
differences of some common oil and gas geochemical
parameters are compared.
Comparison of parameter results obtained from
different instruments shows that, among calculated 20
common oil and gas geochemical parameters, most
of them (17 parameters) have a deviation within 5%,
which indicates that comprehensive two-dimensional
gas chromatography / time-of-flight mass
spectrometry is equivalent to traditional gas
chromatography-mass spectrometry analysis in
respect of calculation of oil and gas geochemical
parameters.
However, for gammacerane/αβ-hopane, 2-ethylnaphthalene/1-ethyl-naphthalene
(ENR), (2,6dimethyl-naphthalene
+ 2,7- dimethylnaphthalene)/1,5-
dimethyl-naphthalene (DNR), the
results from two instruments deviate significantly. This
is because during traditional gas chromatographymass
spectrometry inspection, because of the
limitation of the peak capacity and separating power
for chromatographic column, compounds will form
codistilled peak, or disturbed by other substances,
quantitative results are influenced.
Comprehensive two-dimensional gas chromatography
/ time-of-flight mass spectrometry prevails over
traditional gas chromatography-mass spectrometry in
terms of removing ―codistilled peak‖ effectively.
The former may generate relatively real baseline,
more accurate quantitation of compounds and
accordingly more objective oil and gas geochemical
parameters.
Comprehensive two-dimensional gas chromatography
/ time-of-flight mass spectrometry is one of effective
tools for oil and gas geochemical study.
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