江陵凹陷烃源岩热演化史探讨

Thermal Evolutional History of Hydrocarbon Source Rocks in Jiangling Depression

以镜质体反射率和今地温梯度为依据,通过计算机模拟技术分析了岩心实测镜质体反射率与古埋深关系,建立了江陵凹陷不同地史时期镜质体反射率分布模型,探讨了该凹陷烃源岩热演化史。研究表明:新沟咀组下段烃源岩在荆沙组沉积未期进入成熟阶段,潜江组沉积未期进入生油高峰期,荆河镇组沉积未期局部进入过成熟阶段,现今处于高成熟-过成熟阶段,这为江陵凹陷成藏研究提供了重要依据。

Based on vitrinite reflectance and present geothermal gradient, computer simulation technique was used to measure the vitrinite reflectance and palaeo-buried depth, a distributive model of vitrinite reflectance in different geohistorical periods was established and thermal evolutional history of the source rocks was discussed. The results show that at the later stage of Jingsha Formation the lower member of Xingouzui Formation enters the mature stage and enters the high stage of oil genesis in the later period of Jianjiang Formation sediment, it is still in high-mature and over-mature period. It provides an important basis for studying hydrocarbon accumulation in Jiangling Depression.