High Resolution Sequence Stratigraphic Division and Isochronous Framework Establishment in Wuerxun-baer Sag

摘要

High-resolution sequence stratigraphy and related technical methods have been widely used in the analysis of complex and changeable continental petroliferous basins in China in recent years.At present,the main fields of oil and gas exploration in Hailaer Basin have been transferred to lithologic reservoirs,so it is very important to find lithologic traps and analyze the favorable formation conditions of lithologic traps..The tectonic evolution,sequence stratigraphic framework and tectonic control over the sedimentary system of Nantun Formation have been studied in depth by predecessors.However,the division accuracy of Nantun Formation can only reach the level of system tract,and the distribution characteristics of sand bodies and source-reservoir allocation under high-resolution sequence framework are seldom studied.Therefore,on the basis of predecessors'research,the author synthetically uses the related technology and methods of high-resolution sequence stratigraphy,and according to the sequence boundary characteristics reflected by drilling,core,seismic and logging data,establishes the high-resolution sequence stratigraphic framework through fine division and correlation of base-level cycles at various levels.The distribution law of sand body under its control and the source-reservoir allocation relationship favorable to lithologic trap formation are studied in order to have important guiding significance for further tapping the potential of lithologic reservoir.