Method for improving prediction precision of oil and gas reservoir by using seismic attribute related to offset distance

Abstract

The invention relates to a petroleum geophysical prospecting processing technology, in particular to a method for improving the prediction precision of an oil and gas reservoir by using the seismic attribute related to offset distance. The method comprises the following steps: a CMP / CRP trace gather is transformed to an angle domain to obtain an angular-trace gather, the partial angle stacking is performed so as to form an angle stacking section, then the angle stacking section is calibrated on the scale of the reflection coefficient of the actual seismic record, and the AVO attribute RE related to the offset distance is extracted on different angle stacking sections; and an oil-gas abnormal boundary is outlined by using the extracted new attribute related to the offset distance. The invention performs gather operation only to different angle stacking sections and remarkably improves the efficiency of the attribute extraction method based on the AVO technology. In addition, the random noise is suppressed during the implementation process by stacking partial angles, and the non-determinacy of the inversional result of the AVO attribute due to the too less offset data inversed before stacking owing to the NMO correction stretching is avoided.

Description

technical field [0001] The invention relates to a petroleum geophysical prospecting seismic data processing technology, and is a method for finely describing oil and gas anomaly boundaries and improving the prediction accuracy of oil and gas reservoirs by using seismic attributes related to offset. Background technique [0002] Seismic exploration is to artificially stimulate seismic waves, record the formation response of seismic waves with single-component or multi-component sensors on the surface or underground, study their propagation laws in the formation, and find out the underground geological structure through seismic data processing and inversion. Lithological characteristics, and then geophysical exploration methods to find mineral resources such as oil and gas. [0003] The ultimate goal of seismic exploration is to comprehensively utilize the kinematics and dynamics characteristics of seismic waves to obtain as much comprehensive stratum information as possible a...

AI Technical Summary

Problems solved by technology

Aiming at these problems, Wang (1999) discussed the possibility of simultaneously inverting lithological parameters such as P-S wave velocity and velocity ratio by using nonlinearity while giving the approximate formula of high-precision reflection coefficient. Implemented iteratively, susceptible to initial values, and cannot provide density estimates

Larsen (1999) used multi-component AVO joint inversion to reduce the uncertainty of the inversion results, but the joint inversion is based on fine horizon calibration, if the horizon calibration is not good, the inversion results will lose their reliability and meaning

In addition, many companies at home and abroad try to use global optimization algorithms such as neural networks, genetic algorithms, and simulated annealing to perform three-parameter AVO inversion. Although this global optimization method can give theoretical optimal estimates, it often cannot give Satisfies reasonable estimates for geophysical problems, especially when there is little information about a priori constraints

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