成岩史模拟与成岩阶段预测——以黄骅坳陷碳酸盐岩为例

通过在时空领域内模拟镜质组反射率、古地温、伊/蒙混层中蒙皂石层含量和甾烷异构化率的变化，建立了碳酸盐岩成岩作用数值模拟系统。模拟结果表明，黄骅坳陷奥陶系碳酸盐岩在加里东期处于早成岩阶段，海西期-印支期处于中成岩阶段A期，燕山期进入中成岩阶段B期。古近纪-现今，奥陶系下部碳酸盐岩一直处于晚成岩阶段，但中、上部地层仍处于中成岩阶段。目前，在黄骅坳陷的北部和南部地区，奥陶系碳酸盐岩进入中成岩阶段B期，有利于天然气的生成与聚集；中部地区则处于中成岩阶段A期，可以生成和聚集液态烃，是石油勘探的有利地区。

SIMULATION OF DIAGENETIC HISTORY AND PREDICTION OF DIAGENETIC STAGES: TAKING CARBONATES IN HUANGHUA DEPRESSION AS AN EXAMPLE

A numerical simulation system of carbonate diagenesis is built through modeling variations of vitrinite reflectance (R_o), palaeogeothermal, content of smectite in I/S mixed layers and sterane C_ 29S/R+S in time and space. Simulation results indicate that the Ordovician carbonates were in the early diagentic stage during the Caledonian epoch, and were in the middle diagenetic stage A from the Hercynianin epoch to the Indo-Chinese epoch,and entered the middle diagenetic stage B in the Yanshan epoch. From Paleogene till present, the carbonates in the lower interval of Ordovician have been in the late diagenetic stage, but the carbonates in the middle and upper intervals of Ordovician were still in the middle diagenetic stage. At present, the Ordovician carbonates are in the middle diagenetic stage B in the southern and northern Huanghua depression, which is favorable for generation and accumulation of natural gas. While the Ordovician carbonates are in the middle diagenetic stage A in the middle part of the Huanghua depression, which is favorable for generation and accumulation of liquid hydrocarbons, thus this area is favorable for oil exploration.