塔里木盆地群5井和曲1井原油的油源研究——脂肪酸及烷基环己烷系列化合物提供的新证据

STUDY ON THE OIL SOURCE OF CRUDE OILS FROM WELL QUN-5 AND WELL QU-1 IN THE TARIM BASIN-NEW EVIDENCES FROM FATTY ACIDS AND ALKYL CYCLOHEXANES SERIES COMPOUNDS

段毅 周世新 孟自芳

DUAN Yi ZHOU Shi-xin MENG Zi-fang

中国科学院兰州地质研究所, 甘肃, 兰州, 730000

State Key Laboratory of Gas Geochemistry, Lanzhou Institute of Geology, Academy of Science, Lanzhou 730000, China

塔里木盆地群5井和曲1井原油中的脂肪酸主要来自母源,其组成特征反映了母质主要为菌藻类.群5井和曲1井原油含有丰富的烷基环己烷系列化合物.脂肪酸和烷基环己烷系列分布特征,在群5井和曲1井原油中差别显著,反映了它们具有不同的油源.结合原油的碳同位素、长链三环萜烷、藿烷和甾烷组成特征,认为塔里木盆地群5井原油可能来自寒武-奥陶系海相碳酸盐岩生油岩,而曲1井原油可能来自石炭系海相泥岩生油岩.

Oils from well Qun-5 and well Qu-1 in the Tarim Basin contain abundant fatty acids and a series of long-chain alkyl cyclohexanes.The compositions of fatty acids are in the range of C10-C26,and exhibit a model distribution with maximum at C16 for oil from well Qun-5 and at C 15 for oil from well Qu-1.Studied data show that these fatty acids come mainly from their source rocks and are derived from algae and bacteria.The compositions of long-chain alkyl cyclohexanes are in the range of C12-C32.They contain a model distribution with maximum at C13 for oil from well Qun-5 and bimodel distributions with maxima at C14,C15 or C19.Significant differences in the distributions of fatty acids and long-chain alkyl cyclohexanes in oils from well Qun-5 and well Qu-1 indicatethat these oils have different oil sources.Together with the features of compositions of carbon isotopes,long-chain tricyclic terpanes,hopanes and steranes,it is suggested that oil from well Qun-5 originate from Cambrian-Ordovician marine carbonate source rock and oil from well Qu-1 originate from Carboniferous marine mudstone source rock.

中国科学院知识创新工程(KZCX2-1);“九五”国家重点科技攻关项目(96-111-01-04-02);国家自然科学基金(400072040)

https://doi.org/10.11781/sysydz200104433