东海盆地台北坳陷有机包裹体化学成分及成因

利用LAM、热爆-气相色谱等方法对东海盆地台北坳陷第三系储层中有机包裹体成分进行了系统研究,结果表明:1矿物包裹体中以CO₂为主,同时含有一定的N₂和F₂等,气态烃包裹体中CO₂含量一般可达40%～78%,液态烃包裹体中CO₂含量一般23%～41%;2烃类含量一般<30%,其中甲烷含量较低,C₂～C₇轻烃含量比甲烷含量高,甲苯含量较高(达18.8%);3对主要烃源岩加水热模拟实验也具有同样的特点。这些特点说明CO₂的成因与烃源岩中碳酸盐矿物热解有关,有机包裹体的成因类型偏腐植型,气态烃以湿气为主,且含有一定的凝析油成分,和南海盆地第三系储层中有机包裹体具有相似的特征。

ORIGIN AND COMPOSITION OF ORGANIC INCLUSIONS IN TAIBEI DEPRESSION, DONGHAI BASIN

The organic inclusions in the Taibei Depression, Donghai (the East China Sea) Basin, are studied by LAM and perogenation Gc, with results as follows. ①CO₂ is mainly component in the organic inclusions, which is 40%~78% in the gas hydrocarbon inclusions and 23%~41% in the liquid ones respectively, at the same time, there are some N₂ and F₂ . ②The component of hydrocarbon in the organic inclusions is <30%, in which, the CH₄ is less, and the C₂~C₇ is more, the toluene is 18 8%. ③The same characteristics can be observed in the simulation experiment. The composition of organic inclusions shows that the origin of CO₂ is related with the carbonate mineral in source rocks, original type of organic inclusions is III, the gas hydrocarbon is mainly humidity. All of these are similar to the organic inclusions in the Nanhai (the South China Sea) Basin.