中国新生代生物天然气藏的基本形成模式

受新生代大地构造演化分区及古地理、古气候分区的控制,我国新生代盆地发育5种生物气藏的基本形成模式。第一类是西北部山间大型走滑挤压坳陷盆地的高原、高纬度、高海拔、寒冷、干旱气候下的内陆咸化湖、盐湖生物天然气藏;第二类为西南部山间超小型走滑拉分裂陷盆地的热带亚热带、潮湿气候下的内陆微咸水、淡水湖成因的生物天然气藏;第三类为东南沿海亚热带区平原、河口湾相、大型三角洲相区的第四系生物天然气藏;第四类为东部走滑拉张裂陷盆地的混合成因生物天然气藏;第五类为南海准被动大陆边缘上第三系—第四系亚热带、热带贫营养滨浅海生物成因天然气藏。

BASIC FORMING MODELS OF THE CENOZOIC BIOGAS POOLS IN CHINA

Under the control of geotectonic evolution zonality and paleogeographic and paleoclimatic zonality of the Cenozoic, five kinds of basic forming models of biogas pools were developed in the Cenozoic basins of China. The first pools are in salt lakes and inland salt lakes in the circumstances of highlands, high latitude, high elevation and cold and dry climate, which are located in large intermontane strike-slip compressional down-warped basins in the northwestern part of China. The second are in inland brackish water and fresh water lakes under humid tropic and subtropical zone climate, which are located in ultra small intermontane strike-slip extensional rift basins in the southwestern part of China. The third are the Quaternary biogas pools in plain, estuarine facies and large delta facies areas in the southeast coastal subtropical zones of China. The forth are mixed-genetic biogas pools in the eastern strike-slip extensional rift basins of China. The fifth are the Upper Tertiary-Quaternary biogas pools in the poor-trophic shallow littoral areas of tropic and subtropical zones, which are on the quasi-passive continental margins of the South China Sea.