Study On The Sedimentary Evolution Of Baikouquan Formation In Triassic In Mahu Depression Of Junggar Basin

Sedimentation simulation technology is an important experimental method and technical method based on the theory of sedimentology.Sedimentation simulation can verify the sedimentation model,design the model based on the existing problems,reproduce the sedimentation process through simulation,study the influence and control factors,and the distribution of sand bodies,and establish the corresponding deposition model to provide oil exploration and development More practical ideas and directions.The Mahu Sag in this study is located in the central depression of the Junggar Basin and is one of the favorable hydrocarbon generation depressions.Combining the results of previous studies,the Dionisos Sediment Forwarding simulation software developed by the French Petroleum Research Institute was used to combine sedimentary facies,tectonic subsidence,and sequence stratigraphy based on the data of the Triassic Baikouquan Formation earthquake,logging,and cores in the study area.The comprehensive analysis of the data,etc.,establishes the initial sedimentary evolution model by setting the space for accommodation,source supply,and transport coefficient.After comparing the initial sedimentary evolution simulation results with the differences in geological data and sedimentary model recognition,several parameters were simulated and adjusted,and the model was optimized.Finally,a forward modeling of the sedimentary formation of the B aikouquan formation in Mahu sag was performed at 250-244 Ma.,reproduce the process of sedimentary evolution.Through this simulation,the sedimentary environment,the environmental parameters affecting deposition,and the sedimentary facies distribution were analyzed.The distribution and sedimentary facies evolution of the sandstones in the Baikouquan Formation of the Triassic in Mahu Depression are summarized.The sedimentary facies and sand bodies of the third member of the Baikouquan Formation in the Ring-Mahu Depression are controlled by the lake surface elevation.The delta and fan deltas in the Baishang and Baiyi sections are relatively developed,and the distribution range of the sand bodies is large;the sands in the Baisan section are in a range of contraction,mainly in the lacustrine mudstone.The summer salt fan has weaker response to lake level rise and fall,and has a smaller accretion-retreat rate,which is mainly controlled by source of supply.The Karamay fan and Huangyangquan fan have a larger amount of product-retreat and a larger change in morphology.