我国近海海底浅层气分布特征

Distribution characteristics of the shallow gas in Chinese offshore seabed

海底浅层气是一种海洋灾害地质类型,一旦发生灾害,将对经济造成不可估量的损失。本文在相关文献资料和调查结果的基础上编制了1∶50万我国近海海底浅层气分布图。对已发现的我国近海海底浅层气分布特征进行了初步总结与探讨,以期为海上工程建设及减灾防灾提供重要的环境资料与参考。我国近海海底分布着大面积的浅层气,在辽东湾、山东半岛滨浅海、长江口、杭州湾、浙江近岸、珠江口、北部湾、琼东南近海、黄河水下三角洲外海海底、长江水下三角洲前缘和前三角洲相,存在大面积以生物成因为主的浅层气;而黄海、东海、南海陆架油气资源区数百米地层中的浅层气受断裂控制,分布有热成成因的浅层高压气囊和气团。

The sub-bottom gas was one of the marine geological disasters.It would cause tremendous loss to the economy.According to the relevant literatures and various types of survey data,the map of the shallow gas distribution in our country＇s offshore seabed was drawn,scaled in 1：500000.The distribution characteristics of the shallow gas found in the seabed was preliminary summarized and discussed to provide important environmental data and reference to the marine engineering construction and the reduction and prevention of disasters.Large area of shallow gas distributed in our country＇s offshore seabed.In Liaodong Bay,Shandong Peninsula in shallow Sea,Yangtze River Estuary,Hangzhou Bay,Zhejiang coastal waters,the Pearl River estuary,North Bay,southeast of Hainan coast,Yellow River Delta outside the seabed,and the leading edge of the Yangtze subaqueous delta and its pre-delta facies,a large area of shallow biogenic gas existed.In a few hundred-meter continental shelf bearing oil and gas resources in Yellow Sea,East China Sea,South China Sea,there were high-pressure gas bags or gaseous mass with thermal genesis controlled by faults.