Study on Sedimentation Simulation Experiment of Gentle-slope Shallow Braided River Delta

The sandbody of gentle slope shallow braided river delta is one of the most important reservoir type,which is rich in oil and gas resources,so it has practical significance to study the formation,distribution and evolution of this type of sandbody.On the background of He8 section of Xiashihezi Formation of Permian system in Ordos basin,the formation process of braided river delta is reconstructed,and the characteristics of sedimentary micro-facies are discussed by using the technology of simulation experiment.The systematic study on the main controlling factors of the formation and evolution of braided river delta is completed,and the formation mechanism of large area sandstone under the background of gentle structures is revealed.The study results show that the basement subsidence,relative lake level changes,flow,sediment supply and so on are the main controlling factors of the formation and evolution of braided river delta;the low slope,abundant sediment supply,strong currents,frequent changes of lake-level and catchment of multiple water systems are the amin reasons for the distribution of large area sandstone.Based on the initial geological pattern and the understanding of simulation experiment,the sedimentary model of the braided river delta of He8 section in Sulige area is set up under experimental condition.