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

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。

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 highmature 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.