Difference Analysis Of Deposition And Reservoir Development Modes Of Different Fault Depressions In Songliao Basin

With the continuous improvement of exploration in recent years,the tight gas in Songliao Basin has gradually become the focus of oil and gas exploration.However,from the tight gas reservoirs found at present,there are great differences in sedimentary systems,reservoir development patterns and distribution characteristics of different types of fault depressions in Songliao Basin.In order to dissect the reservoir-forming characteristics of tight sandy conglomerate gas in different fault depressions in Songliao Basin,the structural types,distribution characteristics and controlling factors of the fault basin are analyzed in detail in this paper.Through field outcrop,core observation,well logging,seismic and other comprehensive study of the deep dense glutenite depositional development model,systematic study of Songliao fault depression reservoir physical properties,rock types,pore structure,diagenesis and sedimentary facies,and analysis of the main differences between typical fault depression.The main achievements are as follows: Firstly,through seismic data,the comprehensive study of typical seismic-geological interpretation profiles of different fault depressions is carried out,the internal structural styles and structural characteristics of different fault depressions are determined,a more detailed classification scheme of deep fault depression types in Songliao Basin is formed,and the development characteristics,distribution rules and controlling factors of different fault depressions are defined.Secondly,four typical and four analogous profiles of Shahezi Formation are selected by exploring the deep outcrop in Songliao Basin and its surrounding areas,and the sedimentary environment and reservoir development characteristics of each member of Shahezi Formation are determined.Because different fault depression structures in Songliao Basin have similar sedimentary system types and different sedimentary filling characteristics,based on the study of fault depression structure types and the anatomy of sedimentary characteristics of typical fault depression,the author clarifies the characteristics of sedimentary filling and the distribution pattern of glutenite body under different fault depression backgrounds.Finally,based on the typical fault depression,the characteristics of the fault depression reservoirs in Songliao Basin are defined,and the differences of the characteristics of the typical fault depression reservoirs are compared and analyzed.