本文關鍵詞： 碳同位素 頁巖氣 五峰組 龍馬溪組 焦石壩 石油地質(zhì)　出處：《地球科學》2017年07期 　論文類型：期刊論文

【摘要】：焦石壩地區(qū)五峰組-龍馬溪組頁巖富集有大量的天然氣,但針對頁巖氣地球化學特征研究還較薄弱,其蘊含的地質(zhì)意義不甚明確.通過頁巖氣組分及其碳同位素特征和頁巖干酪根的碳同位素特征分析,討論了頁巖氣的來源、成因類型和"完全倒轉(zhuǎn)"的碳同位素分布特征.五峰組-龍馬溪組頁巖具有很好的生烴能力、有機質(zhì)豐度與含氣量的關系有明顯的正相關性、甲烷與干酪根相似的碳同位素特征、地層的超壓特征等,綜合表明研究區(qū)天然氣應為頁巖自生自儲的頁巖氣;頁巖氣的甲烷含量均超過98%,其碳同位素平均為-29.93‰,反映了成熟度已經(jīng)達到過成熟干氣階段;相對穩(wěn)定的ln(C_1/C_2)和快速增大的ln(C_2/C_3)揭示其成因主要為二次裂解氣;頁巖氣碳同位素"完全倒轉(zhuǎn)"的分布特征主要受到在相對封閉環(huán)境中的原油裂解生氣作用的影響,其"完全倒轉(zhuǎn)"的碳同位素分布特征也反映了研究區(qū)良好的頁巖氣保存、富集條件.
[Abstract]:The shale of Wufeng formation and Longmaxi formation in Jiaoshiba area is rich in a large amount of natural gas, but the study on geochemical characteristics of shale gas is still weak. The source of shale gas is discussed by analyzing the composition of shale gas, its carbon isotopic characteristics and the characteristics of shale kerogen. The shale of Wufeng formation and Longmaxi formation has good hydrocarbon generation ability, and the relationship between organic matter abundance and gas content is obviously positive correlation. The carbon isotope characteristics of methane and kerogen are similar to those of kerogen, and the overpressure characteristics of strata, etc., which indicate that the natural gas in the study area should be shale gas of self-generation and self-reservoir, and the methane content of shale gas exceeds 98 鈥，

本文編號：1511554