Elżbieta Bilkiewicz Origin of natural gas in the Zechstein Main Dolomite strata… 4 CONTENTS STRESZCZENIE ... 1 LIST OF TABLES ... 6 LIST OF FIGURES ... 7 ABSTRACT ... 9 INTRODUCTION ... 11
1. MAIN DOLOMITE – OUTLINE OF LITHOSTRATIGRAPHICAL, SEDIMENTOLOGICAL AND TECTONIC CHARACTERISTICS ... 14
2. GENERAL CHARACTERISTICS OF STUDIED PETROLEUM DEPOSITS ... 17
2.1 BUK OIL DEPOSIT ... 17
2.2 JAROCIN GAS DEPOSIT ... 17
2.3 KIJE OIL-GAS DEPOSIT ... 17
2.4 MOZÓW S OIL DEPOSIT ... 18
2.5 OŁOBOK OIL DEPOSIT ... 18
2.6 POŁĘCKO OIL-GAS DEPOSIT ... 18
2.7 RADOSZYN OIL DEPOSIT ... 18
2.8 RETNO OIL DEPOSIT ... 19
2.9 TARCHAŁY GAS DEPOSIT ... 19
2.10 WYSOCKO MAŁE E GAS DEPOSIT ... 19
3. ORIGIN OF NATURAL GAS BASED ON MOLECULAR AND STABLE ISOTOPE COMPOSITIONS ... 20
3.1 THEORETICAL BASIS AND GENETICAL ENTANGLEMENTS OF ISOTOPE FRACTIONATION ... 20
3.2 HYDROCARBON GASES ... 22
3.3 ORIGIN OF NON-HYDROCARBON GASES ... 27
3.3.1 Carbon dioxide ... 27
3.3.2 Hydrogen sulphide ... 29
3.3.3 Molecular nitrogen ... 30
3.4 COMPARISON OF NATURAL AND HYDROUS PYROLYSIS GASES ... 32
4. RESEARCH MATERIAL AND SAMPLING ... 34
4.1 SOURCE ROCK ... 34
4.2 NATURAL GAS ... 34
4.3 GAS GENERATED DURING HYDROUS PYROLYSIS EXPERIMENTS ... 34
5. METHODS OF ANALYTICAL AND EXPERIMENTAL STUDIES ... 35
5.1 SOURCE ROCK ANALYTICAL STUDIES ... 35
5.1.1 Sample preparation ... 35
5.1.2 Rock-Eval pyrolysis ... 35
5.1.3 Stable carbon isotope analysis of kerogen ... 36
5.1.4 Elemental analysis of kerogen ... 36
5.1.5 Random reflectance of dispersed organic matter ... 37
5.2 HYDROUS PYROLYSIS EXPERIMENTS ... 37
5.2.1 Sample preparation for hydrous pyrolysis ... 37
5.2.2 Description of experiments ... 37
Elżbieta Bilkiewicz Origin of natural gas in the Zechstein Main Dolomite strata…
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5.3.1 Molecular composition ... 38
5.3.2 Stable carbon, hydrogen, and nitrogen isotope compositions ... 38
5.4 STABLE HYDROGEN ISOTOPE COMPOSITION OF WATER USED FOR HP EXPERIMENTS ... 39
6. GENERAL CHARACTERISTICS OF SOURCE ROCK – REVIEW OF PREVIOUS STUDIES ... 40
7. RESULTS OF ANALYTICAL RESEARCH ... 41
7.1 SOURCE ROCK ... 41
7.1.1 Rock Eval parameters and indices a basis of selection for hydrous pyrolysis experiments ... 41
7.1.2 Stable carbon isotope composition of kerogen ... 41
7.1.3 Elemental composition of isolated kerogen ... 42
7.1.4 Random reflectance of dispersed organic matter ... 42
7.2 MOLECULAR AND ISOTOPIC COMPOSITION OF ANALYSED NATURAL AND HYDROUS PYROLYSIS GASES ... 42
7.2.1 Molecular composition of natural gas and gas generated during hydrous pyrolysis experiments ... 42
7.2.2 Isotopic composition of natural gas and gas generated during hydrous pyrolysis experiments ... 43
8. DISCUSSION ... 45
8.1 CHARACTERISTICS OF ANALYSED ROCK ... 45
8.2 ORIGIN OF NATURAL GASES ... 46
8.2.1 Origin of hydrocarbon gases ... 47
8.2.2 Origin non-hydrocarbon gases ... 54
8.2.2.1 Origin of carbon dioxide and hydrogen sulphide ... 54
8.2.2.2 Origin of molecular nitrogen ... 57
8.2.2.3 Molecular hydrogen ... 58
8.2.2.4 Unsaturated hydrocarbons ... 59
9. CONCLUSIONS ... 60
REFERENCES ... 62
