The Chang6 reservoir of Ansai Oilfield in the eastern Ordos Basin is a representative example of a low-porosity and extra-low permeability reservoir, characterized by unfavorable physical properties and significant heterogeneity.Traditional reservoir modeling methods are difficult to effectively describe the heterogeneity changes between reservoirs in low-porosity and extra-low permeability reservoirs, which cannot meet the needs of precise oilfield development plan adjustment.Therefore, in order to meet the technical requirements of increasing oil production, the seismic reservoir modeling technology for low-porosity and extra-low permeability reservoirs is explored based on the development seismic of the first block in Ordos Basin.The multi-information seismic-constrained reservoir modeling is proposed.On the basis of combined well-seismic structural modeling and fracture modeling, combined with seismic attributes, the sedimentary microfacies model was constructed by deterministic modeling method based on the results of single-sand level sedimentary microfacies.Under the constraints of sedimentary microfacies model and spatial classification of seismic lithology probability body, a high-precision lithofacies model is established by using sequential Gaussian simulation method.Based on the lithofacies model, the seismic porosity inversion body is usedto further constrain the spatial classification and establish the porosity model.The permeability model is calculated by the empirical formula of pore-permeability relationship, and the oil saturation model is established by Kriging interpolation method. The results show that the seismic constrained reservoir model exhibits evident features of evolving reservoir physical properties, well-defined reservoir boundaries, and clear interlayer configuration relationships.The reliability of the reservoir model established through this technology is further substantiated by analyzing production dynamic data, enabling precise characterization of multi-stage thin sand-body reservoir groups.The technology takes advantage of abundant information of lateral changes of development seismic, solves the problem of inter-well uncertainty of traditional stochastic simulation modeling method, and realizes fine characterization of physical property distribution law of significant heterogeneous reservoirs.The seismic constrained reservoir model has been applied to perfect the corresponding relationship between injection and production and reservoir edge expansion.It provides effective technical support for the stable production of Ansai oilfield and promotes the application of development seismic in Ordos Basin.