High-resolution Sequence Stratigraphy Research And The Difference Evaluation Of Low Permeability Reservoir Of Fuyang Oil Layer In Shang 9 Block Of Yushulin Oilfield

Fuyang reservoir in Shang 9 block of Yushulin oilfield lay in Shangjia nosing structure of Sanzhao sag northeast in Songliao basin, which has shallow burial depth, the scattered distribution of sand body, the complex oil and water distribution and not a unified sequence division, lacking of systematic understanding of the structure and reservoir characteristics. In allusion to these problems, this paper starts with the establishment of a high-resolution sequence stratigraphic framework, analyse the characteristics of sedimentary facies of each unit, achieve the detailed dissection of reservoir characteristics and the study on internal architecture of main sand body, therefore, restoring the actual geological survy, finishing the difference evaluation of low permeability reservoir which is based on the aspects of reservoir physical properties, hetergeneity and flow units.Based on the categorization, identification and description of each sequence boundary,this paper divided Fuyang oil-layer in Shang 9 into 2 long, 8 medium and 75 short term base level cycle which established the high-resolution sequence stratigraphic framework in study area, by the means of introduction of adjacent area skeleton section, optimization of the skeleton section, combination of logs and seismic data and so on. Moreover, this paper, on the basis of previous view, stratum and sand thickness, the ratio of sand and formation, heavy minerals and the distribution of sand body, determined the sediment mainly coming from the northeast. Meantime, combining well logging with mud logging data, we established logging microfacies model which contain 2 subfacies and 12 microfacies and to distributary plain subfacies mainly, to delta front subfacies supplement, achieving the sedimentary microfacies details dissection of 75 sequences in study area, and this paper still finished the study of internal architecture and established the internal configuration model of SSC61. On the basis of the above research, we finished the analysis of physical properties and oil-bearing,established the classification criteria of reservoir flow unit which is based on the data of seepage coefficient, storage coefficient and net-to-gross ratio, achieving the flow unit evaluation, finally this paper finished the difference evaluation of low permeability reservoir from the physical properties, hetergeneity and flow units.