Study On Sedimentary System Of Kong Member 3 In Kongnan Area In Huanghua Depression

Kongnan area is the second oil-rich sag of southern Huanghua Depression,from Kongnan bulge to Dengming temple ; 4700km2 area.The hydrocarbon resource of Kongnan area's feature is small but rich. As demonstrated by many years'petroleum exploration, Kongnan area is abundant of petroleum resources in Ek2 of Kongdian Formation. However, there are some differences in previous researches on deposit sourcees and sedimentary systems.Aimed at the above research meaning and problems, this thesis studying on Ek3 of Kongnan area, analyses its isochronal stratigraphic framework, the types of sedimentary systems and paleo-river systems and basin margin types, then reveals sedimentary systems spatial distributing feature and deposition filling patterns through theories and methods of Sedimentary Geology and Continental sequence stratigraphy. Utilizating the datas of drilling core, well log, seismic and interior testing analysis, based on sedimentary facies indicator analysis, and also according to the characters of rock association, sedimentary structure, section structure and evolutionary series, it identifies 6 types of depositional systems, including braided river delta, fan delta meandering river delta, beach bar, tuibidite fan and lake. And the paper establishes typical phase sequences.Utilizating the components of grave and sandstone, heavy minerals and sandstone bodies dispersion system to analyse paleo-provenances and paleo-river systems, it identifies that there were four provenance areas, northern, eastern, southern and western provenance area. And it developed two types of paleo-river systems, braided river systems and meandering river systems.Based on the above analysis, this paper analyses on the sedimentary system and the spatial distributions of Kong Member 3. Restricted in the type of basin margin, It summarizes the four kinds of depositional systems, braided river delta-lake, alluvial fan-alluvial plain, meandering river delta-lake, and fan delta-lake depositional systems.Deposition time of the Kong Member 3 in Kongnan area is during the first cracking in north China, and is also during the earliest development of Cenozoic fault basinin in Huanghua depression. Cangdong faults start its activities and to control the deposition, Kong Member 3 shows early faulting deposition features. structural models of Kong Member 3 is mainly Extensional Structural style.