Density Inversion and Porosity Estimation Using Seismic Data

Formation mass density is directly related to porosity, fluid type, fluid saturation, and matrix mineral composition. The change of the reservoir parameters can cause the change of density and then the seismic velocity, impedance and amplitude. We discussed the characteristics of the changes by theoretical calculation and presented a method for estimating density and porosity based on full acoustic waveform inversion. Because of avoiding the signal distortion caused by more processing, the method can improve the inversion accuracy of density and porosity. It also can eliminate noise by integrating the derivative of wave field along time and summing multi-shot data. The method has been tested successfully by a synthetic example and gas-field data from western China. The density and porosity provided by the method agree with the logging result. It also supplies reliable data for prediction of effective reservoir and calculation of reserves.

[1]  Full Elastic Waveform Inversion: Future of Quantitative Seismic Imaging , 2008 .

[2]  P. Anno,et al.  Imaging oil-sand reservoir heterogeneities using wide-angle prestack seismic inversion , 2008 .

[3]  Mrinal K. Sen,et al.  A comparison of porosity estimates obtained using post-, partial-, and prestack seismic inversion methods: Marco Polo Field, Gulf of Mexico , 2007 .

[4]  G. H. F. Gardner,et al.  FORMATION VELOCITY AND DENSITY—THE DIAGNOSTIC BASICS FOR STRATIGRAPHIC TRAPS , 1974 .

[5]  Tommie Rape,et al.  Density Inversion Using Joint PP/PS Data: Sensitivity to the Angle Range , 2007 .

[6]  K. Innanen,et al.  Multiresolution modeling and seismic wavefield reconstruction in attenuating media , 2002 .

[7]  A. Tarantola.  A strategy for nonlinear elastic inversion of seismic reflection data , 1986 .

[8]  Marwan Charara,et al.  Full-waveform Inversion Results When Using Acoustic Approximation Instead of Elastic Medium , 2008 .

[9]  A. Tarantola.  Inversion of seismic reflection data in the acoustic approximation , 1984 .

[10]  Amit Kumar Srivastava,et al.  Estimation of effective porosity using geostatistics and multiattribute transforms: A case study , 2004 .

[11]  Wenzhi Zhao,et al.  Nonlinear process control of wave-equation inversion and its application in the detection of gas , 2007 .

[12]  J. Harris,et al.  Elastic wave equation traveltime and waveform inversion of crosswell data , 1997 .

[13]  Yongyi Li.  Density anomaly indicators and application , 2006 .