台灣鑽遇地層的碳氫化合物氣體特徵及其在油氣潛能上的意義

Hydrocarbon Gases Occurred in Encountered Formations and Their Significances in Oil and Gas Exploration

翁榮南(J.N. Oung) ； 陳德權(D.C. Chen)

《鑛冶：中國鑛冶工程學會會刊》 47卷4期 (2003/12) Pp. 101-107+94

https://doi.org/10.30069/MM.200312_47(4).0010

摘要

本研究分析台灣海域鑽探井鑽遇地層的碳氫化合物氣體，分析結果顯示台灣北方海域及台西盆地新竹海域下部中新統含煤地層氣體含量相當高，是重要的產氣源岩。下部中新統鏡煤素反射率0.4%－0.5%開始出現丙烷以上氣體，顯示熱生成氣開始生成，部份火成活動對地層中的成熟度有增強作用。台南盆地北部凹陷下部中新統鑽遇地層的碳氫化合物氣體含量普遍低，可能是缺乏含煤層所致。台灣地區大部分鑽遇地層的C_5^+含量偏低，顯示生油岩有機質以產氣型為主。

關鍵字

石油探勘 ； 地球化學 ； 罐頂氣體分析 ； 岩屑氣體

並列摘要

Fresh cuttings collected from drilling wells, offshore Taiwan, were analyzed for hydrocarbon gases using the headspace gas analysis technique. The content and chemical composition of the hydrocarbon gases was applied to evaluate the hydrocarbon generation potential, including organic richness, maturation level and organic matter type, of the encountered formations. The Lower Miocene coal-bearing formations in northern and western offshore area show high content of gases, indicating their potential for natural gas generation. The Miocene in the northern depression of the Tainan Basin shows relatively less gas generation potential compared to the offshore Taihsi Basin, probably due to lack of coal-bearing formations. The threshold of the gas generation is usually at the formation with Ro value of 0.4-0.5% based on the occurrence of C_3^+ hydrocarbons. Major organic matter in all encountered formations is gas-prone, judged from their low C_5^+ content.

並列關鍵字

Oil Exploration ； Geochemistry ； Headspace Gas Analysis ； Cutting gas