Thin Reservoir Prediction And Potential Evaluation Of Suining Formation In Luodai Gas Field,Sichuan Province

The Luodai gas field in western Sichuan is located in the eastern slope of the western Sichuan depression and is located on the west side of the NNE-trending tectonic belt in Longquanshan.The sedimentary subfacies of the Jurassic Suining Formation in the Luodai gas field is the frontal subfacies of the shallow water delta,which is conducive to reservoir development.The microfacies are mainly underwater distributary channels and estuary dams.The thin interbedded layer of sand is the main feature of the sand group.The reservoir thickness of the Suining Formation in the Luodai gas field is thin,the cumulative reservoir thickness is generally less than 10m,the thickness of a single sand body is 5m on average,the physical properties are poor,and the average porosity is 5%.The method of reservoir prediction in the early stage cannot fully adapt to the development of thin reservoirs.With the deepening of exploration and development,the gas reservoir pressure and output in the region are gradually decreasing.How to implement effective and continuous capacity building for Luodai gas field and continuously improve the economic benefits of oil production is the current gas field development needs to be solved Important problem.In this thesis,the wells are combined and the small layer is divided into the entry points.The Jsn₁¹ layer of the main reservoir is divided into Jsn₁¹-1-1 and Jsn₁^1-2.The Jsn₁^1-2 layer sand body is widely distributed and relatively thick.The effect is better.The Jsn₁^1-1 layer sand body is relatively thin,and the identification difficulty is the biggest.The reservoir distribution and development potential are not clear in the early stage.In order to fully utilize the remaining reserves,the reservoir fine prediction work is carried out for the Jsn₁^1-1 layer.Using well logging data and seismic data to carry out high-precision small-layer division in the Suining Formation of Luodai Gas Field and to establish a fine small-layer contrast grid,to carry out targeted improvement of resolution processing methods,and to improve seismic data thin layer recognition ability in three-dimensional Seismic horizon fine picking and trial and error are optimized based on the time window.The amplitude property map is extracted to characterize the distribution characteristics of the dominant underwater channel sandstone facies.Accurate reservoir quantitative prediction is carried out by wave impedance inversion and geostatistical inversion,and sand body thickness plan and porosity plan are constructed by sedimentary facies constraints.Accurate reservoir quantitative prediction is carried out by wave impedance inversion and geostatistical inversion,and sand body thickness plan and porosity plan are constructed by sedimentary facies constraints.Combined with the structure,sedimentary facies,average porosity,sand body thickness and seismic properties?amplitude properties,wave impedance properties?,combined with gas well production,the potential reservoirs of the Jsn₁^1-1 reservoir in the Suining Formation gas reservoir in this area are evaluated for potential and rich in oil and gas.The degree of aggregation is used to classify the favorable areas:Class I is represented as oil and gas enrichment zone,Class II is represented as favorable gas producing zone,Class III is represented as favorable gas producing zone,and Class IV is expressed as sand body development but physical and gas-bearing In the poor area,it is preferred to develop the well location in the Class I area,the drilling capacity is up to expectations,and the development effect is good.