渤海湾盆地渤中19-6气田凝析气成因研究

Origin of Condensate Gas in Bozhong 19-6 Gas Field in Bohai Bay Basin

摘要:

为了研究渤中19-6凝析气藏的成因类型，利用同位素、轻烃参数、金刚烷参数等方法，系统分析渤中19-6凝析气藏，深入研究其形成机理，认为：渤中19-6气田天然气干燥系数较低，碳同位素偏重，成熟度分布在1.50 %左右，综合判断属于偏腐殖型高熟气；渤中19-6气田凝析油双金刚烷含量较高，生物标志化合物含量较低，指示渤中19-6气田凝析油为高成熟原油，且计算原油裂解程度低于20 %，对天然气的贡献量有限，渤中19-6气田天然气主要为干酪根裂解形成。

Abstract:

In order to analyze the genesis and source of Bozhong 19-6 gas condensate reservoir， the genesis and gas-oil relationship of Bozhong 19-6 gas reservoir were analyzed using a series of isotopes， light hydrocarbon parameters， and biomarkers.The results show that Bozhong 19-6 gas field has a low drying coefficient， a heavy carbon isotope， and a maturity distribution of about 1.50 %， representing a hybrid origin and high-mature gas. The content of dicamantane in the condensate from Bozhong 19-6 gas field is high whereas the content of biomarkers is low， showing a characteristic of high-mature oil. This indicates that the cracking degree of normal oil amounts is lower than 20 %. The contribution of natural gas produced from cracking of crude oil is small. The gas in Bozhong 19-6 gas field is mainly formed by kerogen cracking.