The Sequence Research Of Great Campos,in Brazil

The Great Campos basin is the most important hydrocarbon basin groups of Brazil.It is composed of the Santos basin,the Campos basin and the Espiritu santo basin.There are three stage of basin evolution: rift stage(early Cretaceous Neocomian),transition stage(Aptian)and drift stage(Albian).In this paper,we used the data of seismic,logging and combined the global sea level curve and predecessors' studying results to research on the following: Firstly,Great Campos basin is divided into three tectonic units.Secondly,There are two sequences in pre-salt stratum and the sequence boundary is fault-depression transformation.The sequence filling feature is the near shore development delta clastic rock,and the uplift development carbonate rock is far away from the source,and the low-lying development deep water facies.The salt layer is one sequence and post-salt layers are divided into two sequences.There is deltaic-turbidite fan sedimentary system.Finally,we compared the three basin sequence pattern and filling characteristics,and the studying found that Great Campos basin salt formation is under the structure control,due to different basin evolution scale making the sequence filling difference,and make different carbonate development horizon;Salt formation is affected by tectonic movement and global sea level changing.Santos basin and Campos basin is affected by river systems.At SSQ8 period,because river sedimentary convert from Santos bodies to Campos basin,resulting in different sedimentary system development scale.