渤海湾盆地渤中坳陷天然气成藏主控因素与有利勘探方向  

Main controlling factors of natural gas accumulation and favorable exploration target in Bozhong Depression,Bohai Bay Basin

作　　者：牛成民 于海波 胡安文 叶涛 秦德海 华晓莉 梁舒艺 Niu Chengmin;Yu Haibo;Hu Anwen;Ye Tao;Qin Dehai;Hua Xiaoli;Liang Shuyi(Tianjin Branch of CNOOC(China)Co.,Ltd.)

机构地区：[1]中海石油(中国)有限公司天津分公司

出　　处：《中国石油勘探》2021年第6期152-164,共13页China Petroleum Exploration

基　　金：中海石油(中国)有限公司“七年行动计划”重大科技专项课题“渤海油田上产4000万吨新领域勘探关键技术”(CNOOC-KJ135-ZDXM-36-TJ-08-TJ)。

摘　　要：近年来,渤海湾盆地渤中坳陷天然气勘探相继取得重大突破,成为未来天然气勘探的重要区带。基于三维地震、测井、录井等资料和油气地球化学等分析化验资料,系统总结了渤中坳陷天然气藏特点及成藏主控因素,理清了天然气勘探潜力和下一步勘探方向。研究结果表明,渤中坳陷天然气藏主要分布于太古宇变质岩潜山、下古生界碳酸盐岩潜山和新生界古近系砂砾岩体中。天然气藏CO_(2)含量差异大,低含CO_(2)气藏为凝析气,高含CO_(2)气藏为干气。大型天然气藏的形成受多因素联合控制:混合型烃源岩晚期快速熟化高强度生气是大型气藏形成的物质基础,多类型优质规模性储层是大气藏形成的关键,厚层超压泥岩盖层是大中型天然气藏形成的保障。研究表明,厚层超压泥岩盖层覆盖下的潜山和新生界砂砾岩体是下一步渤中坳陷天然气有利勘探方向。In recent years,major breakthroughs have been made in natural gas exploration in Bozhong Depression in Bohai Bay Basin,where is an important area for natural gas exploration in the future.The gas reservoir characteristics and the main controlling factors of natural gas accumulation are systematically summarized,and natural gas resource potential and exploration targets are identified in Bozhong epression in Bohai Bay Basin by using 3D seismic,wireline logging,mud logging,and geochemical lab test data.The results show that the gas reservoirs in Bozhong Depression are mainly accumulated in the Archean metamorphic rocks buried hills,the Lower Paleozoic carbonate buried hills and the Cenozoic Paleogene glutenite reservoirs.The CO_(2) content of natural gas reservoirs varies greatly.The condensate gas is characterized by low CO_(2) content,while the dry gas is high CO_(2) content.The formation of large natural gas reservoir is jointly controlled by multiple factors.The late rapid maturation and high intensity gas generation of mixed source rocks are the material basis,and the multi type,large-scale and high-quality reservoir is the key to the formation of large-scale gas reservoir.The thick and over pressured mudstone caprock is the guarantee for the formation of large and medium-sized natural gas reservoir.The study indicates that buried hill and the Cenozoic glutenite reservoir covered by thick and over pressured mudstone caprock are the favorable exploration targets in Bozhong Depression.

关 键 词：天然气藏 成藏特征 成藏主控因素 勘探方向 渤中坳陷 渤海湾盆地 

分 类 号：TE112[石油与天然气工程—油气勘探]