Logging Sedimentary Microfacies Recognition Method Of Deng 4 Member In Gao Mo Area And Its Application

Marine carbonate rocks occupy an extremely important position in global oil and gas production.Since 2011,breakthroughs have been made in the exploration of the Sinian Deng 4 Member in the Gao-Mo area in the central Sichuan Basin,demonstrating the great potential for oil and gas exploration of ancient carbonate rocks in the Sinian Deng 4 Member in the central Sichuan.The large-scale development of microbial dolomite hills and shoals in the Deng 4 Member of the Gao-Mo area in central Sichuan provides good material conditions for high-quality reservoir.However,due to the control of sedimentary facies,the reservoir distribution has obvious heterogeneity.In this paper,based on geological data such as cores and thin slices,conventional logging,imaging logging and other logging data,the logging identification method of lithologic lithofacies and sedimentary microfacies in the study area is established,and the sedimentary facies of the Deng 4 Member is studied.According to the typical image interpretation plate of imaging logging,the imaging logging facies pattern of the Deng 4member is divided into 4 major categories and 7 minor categories.The rock types in the area are summarized and divided into six types of lithologic lithofacies,and the logging identification standards for various lithologic and lithofacies are established.Based on the division of sedimentary microfacies,combined with conventional and imaging logs,conventional sedimentary microfacies identification standards and imaging logging identification plates were formed,and single-well and continuous-well sedimentary facies analysis was carried out.Finally,a "single factor analysis and multi-factor comprehensive mapping method" was used to quantitatively study lithofacies and paleogeography.The results show that during the deposition period of the lower Deng 4member,The hilly and shoal facies are developed in the platform margin zone of the Gao-Mo area,mainly distributed in the Gaoshiti area,and The Moxi area is mainly dominated by sedimentary deposits between sluic hills and beaches,Yunping sedimentary subfacies predominate within the limited platform facies.During the sedimentary period of upper Deng 4 member,the range of mound-beach facies in the platform margin zone is expanded and distributed continuously.Intraplatform deposits within the platform are developed within the platform,and the lagoon subfacies are restricted by the development of the bunds in the platform.