Underground non-uniform medium seismic investigation complexity quantitative evaluating method

Abstract

The present invention discloses a method for quantitative-evaluating the detection complexity of the underground inhomogeneous medium earthquake. At first the inhomogeneous spectrum of transverse velocity variation of complex structure medium and the inhomogeneous spectrum of the stratum angle variation are calculated. Afterwards, the frequency dispersion relationship of various wave equation seismic transmission operator and the broadband characteristic thereof are analyzed and calculated. Then the frequency dispersion relationship and the broadband characteristic of the seismic transmission operator are correlated with the transverse velocity variation of the complex structure medium and the inhomogeneous spectrum of stratum angle variation. The transmission efficiency of seismic wave in complex medium are calculated through establishing a dot product to the inhomogeneous spectrum and angular spectrum of the seismic transmission operator with the transverse velocity variation of complex structure medium and the inhomogeneous spectrum of the stratum angle variation. Finally the complexity coefficient eta of underground medium variation and seismic detection is defined thereby defining a complexity coefficient phi=1-eta of the underground medium variation. The quantitative evaluation to the complexity of complex medium is realized.

Description

technical field [0001] The invention belongs to the field of petroleum exploration, and relates to a quantitative assessment in complex structural imaging, oil and gas reservoir prediction and reservoir comprehensive evaluation risk assessment technologies. Background technique [0002] The quantification of the complexity of subsurface media has long been a research technique of concern to the scientific community. Comprehensive evaluation of risk assessment, etc. will have a profound impact. [0003] The impact of geological heterogeneity on seismic imaging is so obvious that the effect of imaging algorithms is often a compromise between geological complexity, imaging accuracy requirements, and computing speed. Complex geological structures such as salt domes, steep fault zones and formations, and nappe replacements have strong lateral velocity changes and formation dip angle changes, which directly affect the effect of seismic migration imaging. The complexity of the un...

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Problems solved by technology

Due to the lack of effective theories and methods, coupled with the uncertainty of the physical relationship between reservoir physical parameters or between parameters

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