The Evaluation Methodology In Seismic Prediction For Tight-oil Sandstone

Tight-oil sandstone reservoirs are characterized by low porosity,low permeability,complicated oil-water relationship,diversified mineral and anisotropy,leading to a great challenge for seismic exploration technology.Thus,the new established fluid identification factor and brittleness index,based on the anisotropic rock physics model of tight-oil sandstone,have played important guiding role before forward modeling and inversion.Based on the specialty of tight-oil sandstone,seismic rock physics model of tight-oil sandstone are improved from two aspects,i.e,solid components and pore structures of the rocks,so as to achieve the rock physics modeling for anisotropic tight-oil sandstone based on double-porosity theory.Moever,the influences of fours,i.e,clay content and type,pore connectivity and type,on rock physics modeling are stydied systematically using the new theoretical model.The applicability of new model is vertificated by the real data.Furthermore,the new fluid identification factors,based on the anisotropic model above,are compared with conventional fluid factors in both oil-bearing brittle reservoir and non-reservoir interval.Then,the applicability of new proposed brittleness index and conventional brittleness factor are analyzed based on the characters of tight-oil sandstone.A series of results show that theses two parameters could support the theotetical guidance for the actual prediction.