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

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.

Key words:natural gas;condensate oil;diamantane;oil-cracking;Bozhong depression