| After a long period of water-injection exploration, the South East Block in Dagang Oilfield has entered development phase with a high water cut stage. Although the exploration in this reservoir has experienced several times of adjustment, it is not in place in the whole system:the strong reservoir heterogeneity, fine reservoir lithology, complex pore structure, as well as the complexity of the fault,which make the relationship between water and oil very complicated. All of this issue make it very difficult to discriminate flooding levels by using logging data. As a result, the present technology can’t meet the increasingly complex requirements in flooded layer logging interpretation. Thus, logging interpretation technology in the water flooded layer has become the key to the further-exploration of reservoir.This paper firstly makes an investigation in the key blocks about its firstly two rounds logging interpretation. After that this paper analyzes the changes of the reservoir after flooding, including shale content, resistivity, properties, wettability, lectrical parameters of rock and reservoir formation water salinity and other parameters, which lays the foundation for the establishment of quantitative model to recognize flooded layer. In addition, the paper also analyzes the changes in SP spontaneous potential, resistivity and acoustic travel time curves, to lay the foundation of identify flooded layer.To qualitatively identify flooded layer, we use cross-plot method, SP natural potential baseline shift method, inter-hole resistivity ratio method, radial resistivity ratio method, Fisher discrimination method, discriminant function method and multiple membership density clustering neighbor France and other mathematical methods comprehensively identification flooded layer. Moreover, this paper uses core and log data to establish the calculation molder of clay content, the median particle size, porosity, permeability and saturation reservoir parameter. The calculated results of logging interpretation agree well with the core, which indicates a high model accuracy.Finally, based on empirical formulas and fitting method, by using the data of relative permeability, mercury and nuclear magnetic resonance, the calculation molder of irreducible water saturation and residual oil saturation, relative permeability, water production rate and oil displacement efficiency division flooding level explanatory models are established. At the same time, the standards to identify flooded layer has been established, we have also used the established molder to processe the key zone, a better application has been obtained. |
