Fine Characterization Research on Sedimentary Characteristics of the First Section of Nantun Formation in the Complex Fault Block of Wudong Oilfield

Abstract

AbstractIn view of the inconsistent understanding of the sedimentary types of the first section of Nantun Formation in the complex fault block of Wudong Oilfield, in order to finely describe the sedimentary characteristics of the target layer and provide a reliable geological basis for subsequent search for potential and development adjustments, based on previous research results, using analysis data such as core, lithology, grain size characteristics and logging, etc. to comprehensively analyze the sedimentary facies type of the research block. On this basis, the vertical use of logging data finely identify the sedimentary microfacies, and then use the point-line-surface technology to accurately draw the plane facies, and analyze the physical properties and oil test data to summarize the corresponding relationship with the sedimentary microfacies. The result shows that the first section of Nantun Formation in Wudong Oilfield is a braided river delta sedimentary system. The research block is mainly developed in the front of the braided river delta. The sedimentary microfacies mainly develop between underwater distributary channel, underwater distributary channel microfacies, mouth bar microfacies, Front edge sheet sand microfacies and underwater distributary channel flank microfacies. Among them, the underwater distributary channel microfacies sedimentary sand body has the best physical properties and it is the main reservoir. At the same time, the liquid production intensity is the highest, followed by the mouth bar microfacies, and underwater distributary channel flank microfacies and between underwater distributary channel are relatively poor.KeywordsWudong oil fieldBraided river deltaReservoirSedimentary microfaciesSedimentary characteristics