黄骅坳陷上古生界油气成藏史数值模拟

Numerical simulation of Upper Paleozoic pool-forming history in Huanghua Depression

成藏史数值模拟是通过对成藏温度及成藏诸要素(生、储、盖、运、圈、保)的模拟来研究油气聚集规律,确定成藏主控因素。对黄骅坳陷孔西潜山埋藏史、地热史、生储盖发育史和排烃史的研究表明,上古生界煤系烃源岩主要形成两期油气藏,第一期油气成藏发生在晚侏罗世—早白垩世,该期生烃量有限,成藏规模较小;第二期成藏始于早第三纪且持续至今,是黄骅坳陷的主要成藏期。对上古生界石炭—二叠系成藏条件的综合研究表明,以孔西潜山为代表的黄骅坳陷的成藏主控因素是生、排烃史和构造发育史的匹配以及成藏后的保存条件,次要因素是储集层和盖层条件。

Numerical simulation of pool-forming history was used to explore oil gas accumulation and discuss the major controlling factors of pool-forming by modeling the development history of source reservoir seal rocks and traps as well as the conditions for migration and preservation of oil and gas, and paleotemperature in the Upper Paleozoic of Kongxi Buried Hill in Huanghua Depression. The study of buried history, geothermal history, source-reservoir seal assemblage and hydrocarbon expulsion history of the depression showed that the pools generated by the coal-related source rocks in the Upper Paleozoic were formed in two stages of the Late Mesozoic and the Palaeogene periods to present. In the Late Mesozoic,the hydrocarbon generation quantity was poor and the size of hydrocarbon reservoir was small. The Palaeogene to present was the major stage of pool formation. The formation of pools in the studied area mainly depended on the match of hydrocarbon-generation history, hydrocarbon-expulsion history and structural history and also depended on the preservation conditions of pools after pool formation. The reservoir and cap rocks are the secondary controlling factors for Kongxi Buried Hill in Huanghua Depression.