华北盆地中南部早古生代沉积特征及油气成藏条件

华北盆地下古生界分布广泛,沉积厚度较大。虽然其沉积沉降中心不断迁移,但其迁移性主要受板缘构造活动带影响,板内并未发生构造变形(褶皱、断裂),故沉积环境和沉积厚度差异不大,总体表现为浅水、高能、盆内碎屑丰富的陆表海沉积环境。沉积岩的有机质丰度低,基本无有效生油岩发育。统计了1500余个沉积岩有机质丰度资料,总结了有机质丰度与岩性、沉积相的关系,下古生界碳酸盐岩孔洞型储集层的形成机理及其与构造运动的关系表明,加里东期古岩溶主要发生在太康—开封古斜坡,印支期古岩溶主要发生在郯庐断裂西侧的褶皱和推覆构造带,可形成有工业意义的碳酸盐岩储集层。

Sedimentary characteristics and petroliferous condition of Lower Paleozoic inland sea in south-middle North China Basin

The Lower Palaeozoic groups have the wide range of distribution and thicker sedimentary thickness in North China Basin.The sedimentation and subsidence center of the Lower Palaeozoic is migrated continually,and the migratory property is mostly controlled by the tectonic mobile belt of slab fringe.There is no structural deformation(fold or fracture) in the slab,so the difference between sedimentary environment and sedimentary thickness is small.Generally,the basin shows the inland sea sedimentary environment of shallow water, high energy and abundant detritus.The organic matter abundance of sedimentary rock is low,and there is basically no effective source rock.The organic matter abundances of more than 1500 samples of sedimentary rocks were counted,and the relationship between organic matter abundance and lithology or sedimentary facies was discussed.The relationship between forming mechanism of cave-type reservoir of carbonate rocks in the Lower Palaeozoic and structural movement shows that the ancestral karst in the Caledonian Stage mostly happened in Taikang-Kaifeng ancestral incline,and the ancestral karst in the Indosinian Stage mostly happened in the fold or nappe structural belt in the western Tanlu Fault.They all may form the commercial carbonate rock reservoirs.