EASY%Ro法在滨北地区热演化史中的应用

EASY%Ro动力学模拟方法,适合模拟中高热演化程度的盆地模型.为考察松辽盆地滨北地区热演化历史,采用EASY%Ro动力学模拟方法,恢复了该地区的古地温场,结合现今地温场特征,分析了烃源岩热演化历史.结果表明:滨北地区白垩纪古地温梯度高于现今地温梯度,古地温梯度在晚白垩世为4.3~5.8℃/(100m),第三纪以来降低到3.2~3.6℃/(100m);最高古地温是在白垩系末期,有机质热演化在白垩纪末期达到最高峰.自第三系开始的持续抬升剥蚀(白垩纪末至早渐新世为长期沉积间断)和大地热流值衰减降温,致使热演化作用过程“冷冻”,生烃作用停止.

Application of EASY%Ro model to the research of thermal evolution in Binbei

EASY%R_o model is suitable for simulating basins with mid-high thermal evolution. EASY%R_o model is used to restore paleo-geothermal field of Binbei area in Songliao Basin in order to study the thermal evolution in this area. The simulated results are as follows: the paleo-geothermal gradient was higher than the current, it was about 4.3-5.8 ℃/(100m) before the end of Cretraceous, while it decreased to about 3.2-3.6 ℃/(100m) since Tertiary. The paleo-temperature reached the peak by the end of Cretraceous, as a result the thermal evolution of organic matters in the research area get to the peak by the end of Cretraceous, but it was "frozen" by continuous uplift and erosion and the decrease of the Terrestrial heat flow since Tertiary, which brought an end to the hydrocarbon generation.