东濮凹陷上古生界热演化史与生烃期关系

Relationship between thermal evolution history and stage of hydrocarbon generation of Upper Paleozoic in the Dongpu Sag

根据磷灰石裂变径迹、流体包裹体均一温度及EASY %Ro数值模拟等研究结果 ,结合构造演化及埋藏史特征 ,研究东濮凹陷上古生界热演化史与生烃期次。东濮凹陷上古生界经历了 3个埋藏阶段 :印支期地热梯度约为 3 .0℃ / 10 0m ,上古生界埋藏受控于三叠系原始沉积差异 ,至印支期末Ro值多超过 0 .60 % ,有机质处于生烃早期 ,此后再次抬升至中生代末期 ;喜马拉雅早期 (古近纪 )发生大规模断陷 ,地热梯度为 3 .1～ 3 .9℃ / 10 0m ,东营组沉积后上古生界多达最大埋深 ,在凹陷北部处于成熟—高成熟阶段 ,南部处于高成熟—过成熟阶段 ,发生广泛的二次生烃作用 ;喜马拉雅晚期 (新近纪以来 )地热梯度为 2 .85～ 3 .2 5℃ / 10 0m ,新近系的广泛沉积使上古生界埋深再加大 ,但受热未超过前期。图 3表 3参

The technology of uranium fission tracks in detrital apatites, homogenization temperatures of fluid inclusion and EASY% data modeling synthesizing the characteristics of history of tectonic-bury, thermal evolution history and stage of hydrocarbon generation of Upper Paleozoic in Dongpu Sag show that thermal evolution history of Upper Paleozoic has three stages. The geothermal gradient is 3.0℃/100m in Hercynian-Indosinian. The Upper Paleozoic embedding was controlled by the original Triassic differences. The R _o values could be over (0.60)%, when the organic matter was in an early stage of hydrocarbon generation. The geothermal gradient is 3.1-3.9℃/100m during the stage of massive faulting of early Paleogene. The geothermal gradient is 2.85-3.25℃/100m in late Hyma-layanian (since Neogene), when wide deposition of Neogene deepened the Upper Paleozoic.