地球化學在生油材料的油氣潛能評估中一向佔有重要地位，在自然環境中不容易找到不同成熟度卻又有相同沉積材料與保存環境的煤，因此，可利用熱模擬方式將相同煤樣模擬至不同成熟度。熱模擬是一種研究油氣生成的有效方式，在實驗室中利用控制溫度的方式模擬地質環境，進而評估生油岩的油氣潛能。本研究透過比重離心方法富集低成熟度(Ro = 0.39%)褐煤之分離材料，進行200℃、250℃、300℃、350℃、450℃、500℃、550℃之熱模擬溫度，再將熱模擬完成的樣本與原始煤樣進行熱裂分析、煤素質組成分析、鏡煤素反射率量測等實驗，透過鏡煤素反射率、熱裂分析、油氣產率評估生油潛能，顯示在熱模擬溫度350℃附近生油潛能最高，其對應之鏡煤素反射率為1.35%，Tmax為451℃及產率指數為0.25，此結果與傳統油窗範圍相符。而熱模擬溫度350℃後，Tmax值、產率指數、總油產率皆有大幅度的變化，熱模擬溫度350℃附近可能是熱成熟度的重要轉折點。此外，在高成熟度區域，出現S1高於S2的現象，這可能為碳氫化合物受高溫熱成熟時發生的脫附現象。;Geochemistry plays an important role in hydrocarbon potential assessment of source rocks. In addition, thermal simulation provides an effective way to evaluate the generation of oil/gas from kerogen. This evaluation is performed under different controlled temperature in laboratory so as to simulate different geological and thermal environment. Liptinitic material were enriched by density centrifuge separation of a low maturity (Ro = 0.39%) lignite from China. 200℃, 250℃, 300℃, 350℃, 450℃, 500℃, 550℃ were then simulated in this study. Rock-Eval pyrolysis, vitrinite reflectance and maceral composition were examined after simulation. The results indicate the highest hydrocarbon potential occurred at 350℃, with Ro = 1.35%, Tmax = 450℃ and PI = 0.25, cope with the traditional oil window. Furthermore, Tmax, PI and oil yield exhibit significant change at 350℃, which implies a threshold or turning point in the process at thermal maturation. Finally, S1 > S2 in overmatured samples, which can be attributed to the desorption of hydrocarbon under high temperature.
