The Research On Sedimentary Microfacies And Reservoir Characteristic Of E₁f₁ Formation In Gaoji Oilfield, Jinhu Sag

Through the regional strata correlation, and combined with the index of regional marker beds and fossils, the 1st Member of Funing Formation in Gaoji oilfield was divided into two sand section, 13 sand layers. On the basis of huge research and analysis, such as rock characteristics, sedimentary structure feature, grain size analysis, single well facies and logging facies, we came to a conclusion that the sedimentary facies of 1st Member of Funing Formation in Gaoji Oilfield belong to delta facies, while its microfacies belong to underwater distributary channel, river mouth bar microfacies, far sand dam microfacies, distributary Bay microfacies and front sheet sands microfacies. Finally the sedimentary model is correspondingly established.For the purpose of the comprehensive evaluation of reservoir, we started from the research of reservoir characteristics, for instance diagenesis, porosity evolution, reservoir heterogeneity of 1st Member of Funing Formation in Gaoji Oilfield and so on, especially on the study of reservoir heterogeneity. Furthermore we studied the influencing factors of reservoir heterogeneity, such as the analysis from, the interlayer heterogeneity, in situ heterogeneity, plane heterogeneity. All of that came to a conclusion that reservoir of the 1st Member of Funing Formation in Gaoji Oilfield is a kind of middle porosity- low permeability reservoir.And on the basis of the research of reservoir sedimentary microfacies distribution, the sand body distribution, reservoir characteristics, we carried out the reservoir evaluation, it can be divided into Ⅰ ~ Ⅳ Categories. Among in the Category I is good reservoir, category II is better reservoir, category III is poor reservoir and category IV is non reservoir.