天然氣組份在分辨其有機物來源類型及成熟度的方法及應用結果

本報告建立用組份區辨氣體來源及形成成熟度之鑑識方法，可避開天然氣因其組份易由外來者混合及滲漏、移聚等作用而造成應用的困難，並在碳同位素資料缺乏情況下，可有效應用舊有氣體資料以探討其來源及形成之成熟度。解決油氣田開發較早的地區，因缺乏氣體同位素值，難以瞭解其石油系統的問題。本研究藉由水合熱裂分析結果建立天然氣組份在成熟過程的線性變化，以用於區辨天然氣組份受到滲漏、移聚及混合等自然作用或人為分析所造成影響的程度。而從分析結果顯示nC4/iC4對C2/C3即可用於天然氣成熟度之判斷，另從台灣地區不同地層的煤或國外煤的水合熱裂結果的nC3/iC4對nC4/iC4亦隨有機物成熟度增加而增大。為因應有些盆地缺乏nC3/iC4或nC4/iC4分析資料，另行建立分別由C2、C3、C4、C5等組份以不同方式計算所得之參數1及參數2，二者亦隨有機物成熟度增加而增大，因不同有機物類型差異大，二參數的合用可同時可作為區辨來源有機物類別及生成成熟度。以此組份工具進行土庫曼所產氣之來源及成熟度之對比，結果顯示土庫曼Amu Darya盆地與其西側在南裏海盆地氣體參數值的分佈在相同趨勢線上，前者成熟度較低經地化油氣生成模擬顯示侏儸紀含煤層天然氣生成量最高。土庫曼二區域的值與塔里木盆地牙哈氣田氣體的分佈值疊合，為相似的來源且土庫曼西側氣體成熟度較高，再與南裏海盆地西側的亞塞拜然天然氣比較，則南裏海盆地東側土庫曼岸上天然氣較西側的亞塞拜然天然氣有較高成熟度，這顯示南裏海盆中心土庫曼部份構造具探勘潛能，Amu Darya盆地則在盆地邊緣的阿富汗境內具有探勘潛能。

關鍵字

南裏海；天然氣組份；石油系統

並列摘要

This report establishes a method of using natural gas components to identify the genetic origin and maturity of the natural gas. It enables us to recognize the petroleum system without the use of carbon isotope data. We can do so even for contaminated or adulterated natural gases. This study uses the hydrous pyrolysis result to establish the lineation of natural gas component during maturation. Results of hydrous pyrolysis analysis of Taiwan coals and overseas coals demonstrate that nC4/iC4 vs. C2/C3 and nC3/iC4 vs. nC4/iC4 increase with the advance of organic maturity. The results are applicable for contaminated or adulterated natural gases. Two parameters were established using the C2, C3, C4 and C5 components through several correlative computations. These two parameters also increase with the advance of organic maturity, and thereby can be used to recognize genetic type of the natural gas. We applied the method for Turkmenistan and Tarim basin studies. Results show that the natural gases of these areas were derived from similar organic sources. The maturity of natural gas from the Amu Darya basin is lower than that in west Turkmenistan. These data also reveal that structures in the central South Caspian Sea Basin in Turkmenistan have a high exploration potential.

並列關鍵字

south Caspian sea ； natural gas component ； petroleum system

主題瀏覽