论文部分内容阅读
查干凹陷是内蒙古银-额盆地最具勘探潜力的凹陷,为了揭示查干凹陷中、新生代热史及烃源岩热演化历史,首先利用9口井的镜质体反射率数据恢复了查干凹陷中、新生代热史,结果显示查干凹陷在早白垩世巴音戈壁组沉积开始至银根组沉积末期,地温梯度逐渐增加,且到银根组沉积末期达到最大,为50～58℃/km;自晚白垩世乌兰苏海组沉积开始至今,地温梯度逐渐下降,现今地温梯度仅为31～34℃/km.再以热史为基础,结合沉积和构造发育史及烃源岩地球化学资料,模拟了查干凹陷9口井3套烃源岩的成熟度演化历史,模拟结果显示查干凹陷烃源岩成熟度演化受古地温控制,3套烃源岩成熟度都在早白垩世晚期达到最大.
In order to reveal the Mesozoic and Cenozoic thermal histories and the thermal evolution history of source rocks in the Chagan Sag, the Chagan Sag was first recovered from the vitrinite reflectance data of 9 wells During the deposition of the Early Cretaceous Bayingebi Formation to the end of the deposition of the Yingen Formation, the geothermal gradient gradually increased and reached its maximum at the end of the deposition period of 50-50 ℃ / km. Since the Late Cretaceous, the geothermal gradient gradually decreased from the beginning of the Ulan-Suhai Formation, and the present geothermal gradient is only 31 ~ 34 ℃ / km. Based on the thermal history, combining with the history of sedimentary and tectonic evolution and source rocks, The results show that the evolution of maturity of source rocks in the Chagan depression is controlled by paleo-geothermal temperature and the maturity of three sets of source rocks are in the early Cretaceous The late stage of the world to reach the maximum.