| 摘要: | 有機材料熱成熟作用可記錄深埋史上最強烈的熱事件。在熱力作用下，有機質同時存在分子結構縮聚和部份分子鍵斷裂降解二個相反的反應方向。隨著演化程度加深，油母質結構中的支鏈及雜原子基團斷裂脫落，芳香性縮合程度增高，其H/C 原子比改變，因而使有機質成熟度產生改變，並影響其生油潛能，且H/C 原子比值隨鏡煤素反射率（Ｒ o％）值增加而減小。因此，建立有機質在受熱過程的相關指標至為重要。而烴類的甾烷及?烷其相關參數已被廣泛的用來評估熱成熟度，不同的Ro ?階段，適用不同的烴類成熟度參數，必須要進一步詳細探究，方可建構有效的有機材料生油潛能指標。有機材料生烴潛能與油母質的類型、沉積環境及成熟度密切相關，其可能涉及的參數與有機質丰度有關的如TOC、S1、S2 等，與品質有關的如Atomic H/C、HI、BI、QI 等，及與成熟度有關的如Ro%、Tmax、PI 等。這些參數彼此間必存在著某些相關性，可以數學及統計分析的方法進行更深入探討。本研究擬透過煤素質分析、鏡煤素反射率量測、Rock-Eval 熱裂分析、元素分析與多變量統計分析等建構確實有效之生油潛能評估參數，並探究各項評估參數的相關性，以期獲得較佳的生烴潛能評估指標，且能對油氣潛能與探勘提供建議。 ; Rock-Eval pyrolysis is one of the most widely used method for assessing the petroleum generative potential and thermal maturity. The total genetic potential of organic matter in the synthetic assessment of petroleum potential is evaluated by hydrogen index (HI, S2/TOC), bitumen index (BI, S1/TOC), and quality index (QI, (S1+S2)/TOC). Although organic matter has various types of evolution, thermal maturation process is an important factor in hydrocarbon generation. The maturity of organic matter is one of the most important parameters in the evaluation of oil-gas potential. In the assessing maturity of organic matter, vitrinite reflectance (Ro%) is the mostly examined parameter. There are three major characteristics need to be studied for getting good petroleum potential in source rock: properties of organic matter, mature process, and hydrocarbon abundance. Because of pressure increases the activation energies of organic matter in maturation reactions, which might lead to the suppression of vitrinite reflectance. In addition, vitrinite reflectance may also be strongly influenced by oxidation, so we must be careful in avoiding the underestimation or overestimation of Ro% values. In order to achieve a reliable synthetic evaluation of petroleum potential, the process of thermal maturation which varied as the organic matter altered, needs to be studied in detail. The maturation process is irreversible, not influenced by retrograde metamorphism, can only record the maximum thermal event in the burial history. During the thermal maturation process, the construction of hydrocarbon maturity is the most important work. The sterane and terpane isomerization ratios have been applied widely for the assessment of thermal maturity in crude oils and their source rocks. Rock-Eval pyrolysis and TOC determinations are the most widely used methods to characterize source rocks. Traditionally, the hydrogen index (HI) is used to assess the oil and gas potential of source rocks, unless calibrations between the hydrogen index and pyrolysis GC are done. We can use Rock-Eval and TOC data to give a rapid assessment of the average oil- and gas-producing constituents in source rocks. Therefore, the maturity parameters of hydrocarbon must be explored in order to construct the effective indices for the assessment of petroleum potential. The reflectance of vitrinite is a widely used parameter as a geothermometer for the estimation of the thermal maturity. But three problems have occurred about human mistakes, technical problems, and problems associated with the structural and compositional inhomogeneity of organic matter. In most cases the first two types of uncertainties can be handled by standardization (ASTM, ISO). The handling of the third problem may be solved by statistical analysis. The purpose of this study is to establish the reliable indices of synthetic assessment of organic matter in the evaluation of petroleum potential. The scope of this study will be focused on maceral composition analysis, vitrinite reflectance measurement, Rock-Eval pyrolysis, elemental analysis, and multivariate statistical analysis. In addition, it is to present new guidelines for improved assessment of the kerogen type, generative potential and thermal maturity using Rock-Eval parameters. ; 研究期間 9701 ~ 9712 |
