松辽盆地东南隆起氧化作用与有机质的演化

OXIDATION AND ORGANIC MATTER EVOLUTION IN SOUTHEAST UPLIFT OF SONGLIAO BASIN

王永春 苗洪波 刘长伟 景成杰 王亚波 于淑梅

Wang Yongchun Miao Hongbo Liu Changwei Jing Chengjie Wang Yabo Yu Shumei

有机质在遭受氧化作用后,其元素的组成比例、最高热解峰温、生烃转化率及镜质体反射率均发生了较大的变化,常规判识有机质演化程度的指标已失去意义。松辽盆地东南隆起区的研究结果表明 :有机质在遭受氧化作用影响后,干酪根元素的O/C比随演化程度的加深而迅速降低,致使其反映的演化程度高于实际值;有机质氧化后,导致增高;经过氧化的有机质在相同的热力条件下,具有较高的转化率;在强氧化作用下形成的镜质体,其反射率值比正常情况下增长大,强还原环境下则减小。因此,在研究松辽盆地东南隆起区的有机质演化,特别是营城组的演化时,不能以某一指标而定论。

When organic matter undergo oxidation,the compositive proportion of elements,the highest pyrolysis peak temperature,the rate of hydrocarbon conversion and vitrinite reflectance would change distinctly,the conventional distinguishing index of organic matter evolution would lose its significance.The study results of the southeast uplift in Songliao Basin show that after the oxidation of organic matter,the O/C ratio of kerogen decreases with the increasing of evolution degree,thus reulting in the reflected evolution degree higher than the actural one and increasing in .The oxidated organic matter usually has higher conversion ratio under the same thermal condition.The reflectance of the vitrinite formed in strong oxidation condition is higher than in normal circumstance,and that in strong reduction condition reduces.Therefore,to study the evolution of organic matter in the southeast uplift,especially in Yingcheng Formation of the uplift in Songliao Basin,one could not make a conclusion according to a certain index.

10.11743/ogg20000110