渤海湾盆地东濮凹陷桥口—白庙地区古近系沙河街组天然气成因  

Origin of the Natural Gas from Paleogene Shahejie Formation in the QiaokouBaimiao Areas of the Dongpu Depression,Bohai Bay Basin

作　　者：李才学[1] 陈峰[1] 

机构地区：[1]中国石化中原油田分公司采油六厂,山东东明274511

出　　处：《天然气地球科学》2015年第11期2114-2121,共8页Natural Gas Geoscience

摘　　要：通过分析渤海湾盆地东濮凹陷桥口—白庙地区古近系沙河街组天然气的组分、稳定碳同位素特征,对其天然气成因类型、成熟度和混源比例进行了研究,取得以下认识:桥口—白庙地区古近系沙河街组天然气成因复杂,有煤成气、油型气和混合气3种天然气类型;桥口地区烷烃气中甲烷含量明显低于白庙地区,而重烃气含量较高;白庙地区天然气成熟度普遍高于桥口地区,前者为成熟—高成熟阶段的烃源岩生成,后者为成熟早期—成熟阶段生成;桥口地区的桥14井、桥73井和桥76井为典型的油型气,主要来源于沙三段腐泥型有机质。白庙地区靠近兰聊断层的白3井和白8井,天然气为典型的煤成气,来源于石炭系—二叠系煤系地层。桥口地区的混合气以油型气为主,白庙地区的混合气则以煤成气为主。2个地区混合成因气具有多套烃源岩层位来源,石炭系—二叠系煤系、古近系腐泥型、腐殖型烃源岩均有贡献。Based on the analysis of chemical components and stable carbon isotopes of the natural gases from the Paleogene Shahejie Formation in the Qiaokou-Baimiao areas of the Dongpu Depression,the origin,maturity and the mixed proportion of the gases are studied,and the following conclusions are obtained.Three types of natural gases have been discovered,coal-derived gas,oil-derived gas and mixed gases.The methane contents in the Qiaokou area are lower than those in the Baimiao area,while the contents of heavy alkane gases in the Qiaokou area are higher.Gases in the Baimiao area were generated by mature to high-mature source rocks,and gases in the Qiaokou area were generated by low mature to mature source rocks.Gases in the wells Qiao 14,Qiao 73 and Qiao 76 are typical oil-derived gas which was sourced from the sapropelic source rocks in the 3^（rd） member of Shahejie Formation.Gases in the wells Bai 3 and Bai 8,close to the Lanliao deep fault,are typical coal-derived gases,and they were sourced from the Carboniferous-Permian coal measures.Mixed gases in the Qiaokou area are dominated by oil-derived gas,while those in the Baimiao area are dominated by coal-derived gas.The Carboniferous-Permian and Paleogene coal measures both contributed to the mixed gases in the study area.

关 键 词：古近系 天然气成因 桥口—白庙地区 东濮凹陷 渤海湾盆地 

分 类 号：TE122.1[石油与天然气工程—油气勘探]