渤海湾盆地孔西潜山构造带碳酸盐岩的成藏史数值模拟

通过碳酸盐岩成藏要素生、储、盖、运、圈、保的数值模拟,建立了成藏史数值模拟系统,并以渤海湾盆地黄骅坳陷孔西潜山构造带为例说明了这一系统的应用.研究表明,孔西潜山构造带奥陶系烃源岩在印支期开始排烃,一次成藏开始;燕山期进入大量生、排烃阶段,成为本区的主要生烃期和成藏期;之后,一次生烃中止;喜马拉雅期该构造带进一步被埋深,开始二次生烃和第三次成藏,二次生烃的量较小.所以黄骅坳陷下古生界原生油气藏的勘探应注重那些位于生烃区在印支期和燕山期形成且未被后期构造运动破坏的古构造. 

NUMERICAL MODELING OF THE ACCUMULATION-FORMING HISTORY OF THE KONGXI BURIED HILL,BOHAI GULF BASIN

A new numerical modeling system of the accumulation-forming history is established by numerical modeling of the essential elements of accumulation formation in carbonate rocks including source rocks, reservoir rocks, seal rocks, traps, primary migration and preservation,and the Kongxi buried hill tectonic belt in the Huanghua depression of the Bohai Gulf basin is used as an example to illustrate the application of this system. As the modeling results show, hydrocarbons were expelled from the Ordovician source rocks of the Kongxi buried hill tectonic belt in the Indosinian period and primary hydrocarbon accumulation began. The Yanshanian period was a main hydrocarbon generation stage and accumulation formation stage, when hydrocarbons were generated, expelled and accumulated in large quantity. Then primary hydrocarbon generation paused. In the Himalayan period, the tectonic belt was further buried and secondary hydrocarbon generation and tertiary hydrocarbon accumulation began. However, the amount of hydrocarbons generated during the secondary hydrocarbon generation was small. So the exploration for Lower Paleozoic primary oil/gas accumulations in the Huanghua depression should focus on the ancient structures that formed in the Indonesian and Yanshanian periods and were not destroyed by the late-stage tectonic movements.