Reservoir Depiction And Fluid Distribution Prediction In The Forth Dengying Formation On Gaoshiti-Moxi Area

From the acquirement of commercial gas flow in gaoshi 1 to the present,the exploration and development of reservoir in denying formation on gaoshi-moxi area has been at a critical stage.At the same time,there has been lots of qualitative research about reservoir in geology.However,quantitative research is lack for the distribution of the reservoir and the fluid.At the same time,it's urgent to find out the distribution of the rupture-porous reservoir which is the best one.So,the response characteristics of reservoir in well logging curve and seismic has been found out on the basis of the geological characteristics of the reservoir;then,prestack seismic inversion and AVO attribute inversion have been used to extract the elastic parameter of reservoir and AVO abnormal attribute;moreover,The prediction of fracture has been used which is aimed at rupture-porous reservoir.Finally,a seismic prediction model of high quality reservoir and gas bearing capacity is established,and the task-reservoir depiction and fluid distribution prediction has been finished.Research shows: The characteristics of conventional well logging curve are usually shown as two low and two high-low gamma,low density and high neutron,high AC.The sensitive parameters of the reservoir are transverse wave velocity(Vs),longitudinal and transverse wave velocity ratio(Vp/Vs),P-wave impedance(Zp),yet there are errors in them which can not indicate reservior.For the response of seismic,reservoir characterized by middle to low intensity and continuous amplitude,and this model of seismic response can be easily depicted on the plane through waveform clustering analysis.Favorable attributes from prestack synchronous inversion are S-wave impedance(Zs),P-wave impedance(Zp)and longitudinal and transverse wave velocity ratio(Vp/Vs),which can judge the reservoir quality when the influence brought by the silicon and the quality of the sesmic are excluded.Furthermore,in order to the accuracy of the seismic prediction,a multiple linear regression method is adopted to predict porosity of reservoirs.The correlation of reservoir porosity to actual porosity is higher by using eight kinds of seismic attribute fusion calculation.Fracture can be predicted by coherence cube and maximum positive curvature,the cracks are mainly banded along the edge of the western side in denying formation.In the AVO attribute,Poisson's ratio,differential density and S-wave reflection coefficient are more sensitive to gas,the total negative of the attribute value and the negative of the attribute's mean value can predict the gas-bearing distribution on the plane,and the gas indication factor fused with thesethree parameters conforms to the actual well.At last,referring to the result of reserve coefficients,prediction of fracture distribution,gas indication factor,combined with the distribution of seismic reflection model and the structural characteristics,prospective and target area has been divided into some degrees.The lv.1 target area is the zone of rupture-porous reservoir,the lv.2 target area is the zone of porous reservoir,the lv.3 and lv.4 target area is the zone of poor reservoir.