Study On Reservoir Characteristics Of Dengying Formation In Moxi Buried Structure In Central Sichuan Area

The Dengying Formation of Moxi structural belt in Sichuan basin area,strong heterogeneity,have many reservoir space type,complex pore structure,is typically carbonate reservoir.according to the complexity reservoir of dengying formation,Based on absorbing and summarizing the results of previous studies,the paper is guided by the theory of carbonate sedimentology,reservoir geology,oil geology,and the updated development in domestic and abroad study.According to the exploration and development of each well in Moxi Gas Reservoir,Make full Use of core,log and the logging information,this paper has made a thorough study on the Moxi dengying formation,Sedimentary Facies,Reservoir Characteristics and logging interpretation of reservoir,proposal that advantageous explore area,Following are the achievements of this thesis:Sedimentary research indicates that,Dengying Formation in Moxi area is mainly composed of carbonate platform facies and shelf facies.According to its sedimentary characteristics,it can be further divided into four sub-facies:open platform,restricted platform,shallow mixed shelf and deep shelf,as well as granular beach,algae beach,lagoon,sand cloud beach and other micro-facies.In this paper,the types and characteristics of sedimentary facies and their relationship with reservoirs are described in detail.The planar distribution of sedimentary facies in each member of Dengying Formation in Moxi area is established,and the sedimentary facies model of Dengying Formation is established.On the basis of macroscopic,microscopic characteristics and geochemical analysis data of drilling core,the paper indicates that The main reservoir lithology,reservoir space type,reservoir physical properties,reservoir vertical and horizontal relationship characteristics.The top boundary of Dengying Formation is the Deng4 Member and the Qiongzhusi Formation at the bottom of the overlying Cambrian strata,and the bottom boundary is the bottom of Dengying Formation and the top of the underlying Doushantuo Formation.To provide the basis for reservoir types,the paper Interpretes and analysis of well logging data,established The logging interpretation model and Image Interpretation Modes of the study area.In addition,summarizes the logging response characteristics of typical gas reservoir in this area.Build the identification method and plate for gas reservoir in Dengying Formation of this study area.Analysis on the gas reservoir has the results of the data on deep-shallow dual laterolog,made the crossplot,divided into gas reservoir,poor gas reservoir and dry reservoir.From the crossplot of ?-SW,we can see that the gas reservoir has hyperbolic characteristics,from the Rt/Rxo-Rt crossplot,we can see that there is gas reservoir at Rt/Rxo>2.Reasonable cutoff values in the reservoirs are thus determined(porosity 2%,and permeability 0.01×10-3 ?m 2).The results of RT/RXO-RT crossplot can basically separate the gas layer,the poor gas layer and the dry layer.The study of the Dengying Formation reservoir is divided into three classes,Combined with the logging response characteristics of three Reservoirs,made logging crossplot,got the standard of reservoir logging parameter response.,It provides a basis for reservoir division in the study area.The reservoir in the western part of Moxi area is better than that in the east by the plane distribution of reservoir layer number and reservoir thickness.According to the distribution of reservoir can be determined by favorable reservoirzones.