渤海湾盆地中南部中—新生代盆地叠合特征及上古生界生烃规律

MESOZOIC-CENOZOIC BASIN SUPERIMPOSITION AND UPPER PALEOZOIC HYDROCARBON GENERATION DISCIPLINE IN THE MIDDLE AND SOUTH OF BOHAI BAY BASIN

胡宗全 朱建辉

Hu Zongquan Zhu Jianhui

中国石油化工股份有限公司, 石油勘探开发研究院, 北京, 100083 2. 中国石油化工股份有限公司, 石油勘探开发研究院, 无锡石油地质研究所, 江苏, 无锡, 214151

Research Institute of Exploration and Production, SINOPEC, Beijing 100083, China 2. Wuxi Research Institute of Petroleum Geology, Research Institute of Petroleum Exploration and Production, SINOPEC, Wuxi, Jiangsu 214151, China

渤海湾盆地上古生界煤系地层是良好的气源岩。该套烃源岩在中—新生代经历了复杂的盆地叠合过程,导致不同地区之间生烃史的差异性。三叠纪、侏罗纪—白垩纪、新生代是上古生界烃源岩所经历的3个生烃阶段。中—新生代盆地的叠合期次、叠合样式和不均衡性控制着上古生界烃源岩在各个生烃阶段的生烃量多少与比例以及生烃中心的迁移,从而控制着上古生界资源潜力及资源分布。该区盆地的不均衡性越到晚期越强,上古生界烃源岩的早期生烃强度较稳定,但在晚期局部地区仍可经历强生烃过程。上古生界经历的盆地叠合期次和上覆地层数越少、中生代埋藏越浅、新生代埋藏越深,其晚期生烃潜力越大。基于"二次生烃"地质模型和生烃史数值模拟,评价了渤海湾盆地中南部各凹陷上古生界生烃潜力。

The Upper Paleozoic coal bearing formation in the Bohai Bay Basin is favorable for gas generation.It has undergone complex basin superimposition,resulting in differences of hydrocarbon generation history among different areas.Triassic,Jurassic-Cretaceous and Cenozoic are the 3 periods of hydrocarbon generation of the Upper Paleozoic source rock.Time,style and imbalance of Mesozoic-Cenozoic basin superimposition control hydrocarbon generation amounts and ratio in different periods and transference of hydrocarbon generation centers,which control hydrocarbon potential and distribution of the Upper Paleozoic.Imbalance of basin becomes stronger in the late period.Hydrocarbon generation intensity of the Upper Paleozoic source rocks in the early period is relatively stable;however,strong hydrocarbon generation may also exist in some regions during the late period.With fewer basin superimposition stages,fewer overlying strata,shallower imbedding depth in Mesozoic and deeper imbedding depth in Cenozoic,the Upper Paleozoic source rocks have greater generation potential in the late period.Based on geological model of secondary hydrocarbon generation and numerical simulation,hydrocarbon generation potential of the Upper Paleozoic in different sags is evaluated.

https://doi.org/10.11781/sysydz200805439