The Detection And Prediction Of Nature Fractured Oil And Gas Reservoirs Using Geophysical Method

Directed by wave theory of fractured media, The elastic parameters of EDA medium are determined in the light of Hudson-fractured theory, And Christoffel equation gives the formula of the phase velocity of P-wave by which, Effects of velocity on behalf of kinetic characteristic and reflection coefficient on behalf of dynamical characteristic form fractured density and azimuty is discussed. The resalts of numerical simulating indicat that velosity of P-wave has gentle anisotropy in fructured media at same time, the change of fractured density and azimuty has a little effects on velosity of P-wave. But the change of reflection coefficient is three times as much as the change of velesity resulted from fractured density, which shows that dynamical characteristic of seismic wave is more sensitive to fracture than kinetic characteristic. Then, by seismic numericac simulating of the buried hill surface and its internal phase and analysis of characteristic of wave-field, the wave-field charalteristic of the buried hill's surface is different to the characteristic of the buried hills' internal phase, and the change of amplitude and frequence is bigger than that of velosity which proves further that dynamical characteristic is more sensitive to fracture than kinetic characteristic. And the change of amplitude is bigger than that of frequence, either burich hills surface or internal phase and either fluid or gas in farcture. So amplitude is sensitive to frarcture than frequece. Then the sensitivity of amplitude to fracture of the buried hill's surface is further bigger than that to fracture of buried hill's internal phase. Therefore the dynamical characteristic is acted as detected parameter for fractured detection( primary amplitude secondary frequence).And the amplitude of mean sguare and central frequence are acted as evaluational parameter, Based on the those studies, the new ideas is put forward that fractured azimuth is dected by lateral difference and fractured density is dected by vertical difference for three facters of fracture ,wavelet acted as analysis tool and direction by wave field characteristic applied the multiple scale edge dectection and self-adaptive edge detection into the detection theory of seismic fractured azimuth, also put forward the wavelet different scale filter method of the fractured azimuth detection. Simultatly, based on the vaviaction of seismic signal-noise ratio, the anthor use the funtion singular method in the seismic data procesy and put forward the wavelet amplitude singular exponentid method and the wavelet power spectrum singular exponential for the fractued density detection. Pirected by the theory of regression analysis, we get the seismic arribute data by the moden specturm estimation and predict the fractured density by the wavelet multiple-scale regression analysis. Also, in our software, we have made the practical seismic data processing by the prediction of fractured amizuth and the fractured density, then evaluated the exactitude of the predictions by the evaluation of the assessment parauceter, and at last confirm one optimum detection methods of fractured amizuth,the wavelet difference scale filter method, and two the optimmer fractured density detection method, the wavelet amplititude singular exponential method and the wavelet power spectrum singular exponeatial method.