冀中坳陷东北部石炭-二叠系烃源岩热史及成熟史模拟

石炭-二叠系煤成气藏是冀中坳陷东北部亟待突破的勘探领域。文中基于大量的钻井、测井、地球化学和古地温资
料，分别模拟构建了大城凸起、文安斜坡和武清凹陷的埋藏史和考虑岩浆热液侵入作用的热演化史。研究结果表明冀中坳
陷东北部石炭-二叠系地层总体上经历了“三沉两抬”的构造演化过程，在印支运动前全区具有近似的演化历史，印支
期、燕山期区内构造演化开始分异，至新生代形成总体“东隆西坳”的构造格局。区内烃源岩热演化包括一次生烃和二次
生烃，并可细分为长期隆升型、后期强烈沉降深成变质型和岩浆热变质型三种类型。一次成烃主要发生在三叠系末期，二
次成烃分别在新近纪和古近纪岩浆侵入期。区内斜坡浅部和隆起区一次成烃，斜坡和凹陷深部为后期强烈沉降深成变质二
次成烃、斜坡和凸起岩浆热液侵入区发生岩浆热变质二次成烃。一次成烃期Ro 值在0.7%左右，不具成藏潜力，二次成烃
期烃源岩可达高熟、过熟阶段，成藏配置条件好，成藏潜力巨大。

Simulation of the Thermal and Maturity History of Carboniferous-Permian Source Rock in the Northeast of Jizhong Depression

Carboniferous-Permian coal-formed gas reservoir in the northeast of Jizhong Depression is a main target exploration field. In this work, the burial history and the thermal evolution history considering the role of magma intrusion were simulated based on a large number of regional drilling, logging, geochemistry and paleo-temperature data. The results show that the Carboniferous-Permian strata in general experienced three stages of subsidence and two uplift stages after deposition in the northeast of Jizhong Depression. The tectonic evolution of the whole research area is similar before the Indo-Sinian orogeny, and began to show difference in the Indo-Sinian and the Yenshanian orogeny. Finally, in the Cenozoic the tectonic framework formed with uplift in the east and depression in the west. The source rocks in the region contain two styles of hydrocarbon generation: primary and secondary. The thermal evolution can be subdivided into three types, namely long-term uplift, later strong subsidence, and magmatic thermal metamorphism. The primary hydrocarbon generation occurred in the late Triassic, and the secondary hydrocarbon generation in Neogene or the magmatism period in Paleogene. Also, primary hydrocarbon generation only occurred in the shallow slope and the uplift regions and the secondary hydrocarbon generation occurred in the deep slope and sags because the later subsidence was strong. The secondary hydrocarbon also occurred in the slope and the uplift with magma intrusion caused by magmatic thermal metamorphism. The hydrocarbon was of non-accumulation potential as a result of low kerogen maturity, which was about 0.7% of Ro, in primary hydrocarbon generation period. However, the hydrocarbon was of accumulation potential because of the high maturity and over-maturity stage of the source rocks, and the good reservoir favorable conditions in the second hydrocarbon generation stage.