Reservoir Configuration Of N 2 1 Reservoir In Gaskule Oilfield, Qaidam Basin

This thesis takes the sedimentary petrology,reservoir characterization and modeling,sequence stratigraphy,petroleum geology,reservoir geology and other related disciplines as the theoretical basis,and adopts synthetically the information of core,debris and logging data,and in accordance with the principle of multiple methods of comprehensive analysis,this research has finished the division and correlation of small layers.Combining with the research production of the prehominid,the author has done the research and analysis of the sedimentary microfacies of the N21 oil deposit.Based on the study of sedimentary facies,guided by the theory of Miall's theory of reservoir architecture,the detailed study of the reservoir architecture has been completed.The results of this study are as follows:According to the characteristics of the formation development of the study area,based on the principle of stratigraphic contrast from point to line to surface and three-in-one,with the method of marker bed,sliced comparative,depositional cycles,constant depth,small layer of the 508 wells in the study has been divided and contrasted.The stratigraphic correlation of the geological profile of 23 lines was completed,ultimately,a fine isochronous stratigraphic framework was established.On the basis of fully understanding the characteristics of the source of the work area,the paleogeographic structure and the change of the regional sedimentary pattern,based on the geological facies and logging facies marks of the drilled strata in the study area,after comprehensive analysis of the core and well logging data of the N21 oil deposit,there sums up:the N21 oil deposit is a lake-braided river delta depositional system.Based on the analysis of single well facies,the relative ratio of the wells and the feature of the face,it is believed that the whole reservoir sedimentary period of the Gasikule N21 oil deposit is a process of Lake retreat,in the early stage,the work area was in the lake environment,followed by crustal uplift,the underwater channel extends to the center of the lake,there appears the braided river delta front deposits.To III reservoir group sedimentary period,the braided river delta front deposits have become the main body,the characteristics of the whole cycle are counter cycle,during which it experienced a series of process of fluctuation of lake level,which caused the lateral differentiation and vertical evolution of sedimentary microfacies.Based on the theory of reservoir configuration of Miall,the interface of reservoir structure in the study area is divided into four stages.The purpose of this study is the configuration of the underground reservoir,sedimentary microfacies are regarded as the configuration unit of this study,and seven different types of configuration units are summarized.Based on the analysis of interlayer identification and lateral phase transition,the longitudinal overlap and lateral stitching of the configuration unit of the braided river delta front are discussed,there are five main types of vertical superposition relation among them,and the side stitching relation is divided into seven categories.The 24 types of lithofacies of the different configuration units are summarized in the established configuration units.Finally,based on the above research results,the configuration model of the study area is designed.