Method and system for anisotropic velocity modeling

Abstract

The invention provides a method and a system for anisotropic velocity modeling. The method for the anisotropic velocity modeling comprises performing a first iteration process to obtain an initial inclined lateral isotropic velocity, an initial formation dip angle, and an initial azimuth angle corresponding to the time that a near-offset of a first pre-stack depth migration gather has been leveled; performing a second iteration process to obtain a second inclined lateral isotropic velocity, a first formation dip angle, a first azimuth angle, a first anisotropic parameter, and a second anisotropic parameter corresponding to the time that the near-offset of a third pre-stack depth migration gather has been leveled; performing a third iteration process to obtain a fourth anisotropic parametercorresponding to the time that the near-offset of a fourth pre-stack depth migration gather has been leveled; and obtaining an anisotropic velocity model based on the fourth anisotropic parameter, athird inclined lateral isotropic velocity, a second formation dip angle, a second azimuth angle, and a third anisotropic parameter. According to the method and the system for the anisotropic velocitymodeling, the iteration cycle can be shortened; the accuracy of the offset imaging can be improved; and the error between the detected data and the real data can be reduced.

Description

technical field [0001] The invention relates to the field of petroleum exploration, in particular to an anisotropic velocity modeling method and system. Background technique [0002] Prestack depth migration imaging technology is the key technology for accurate imaging of complex structures, which has been generally recognized. Since the assumption of anisotropy is closer to the actual subsurface medium than the assumption of isotropy, the pre-stack depth migration imaging technology based on the anisotropy assumption is more common in industrial production applications. The key to determining the quality of prestack depth migration imaging is the accuracy of the anisotropic velocity model, and the modeling of the anisotropic velocity model is the core of the prestack depth migration imaging processing of complex high and steep structures in the piedmont. [0003] At present, the TTI (tilted transversely isotropic, tilted transverse isotropic) anisotropic velocity model com...

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Problems solved by technology

[0003] At present, the TTI (tilted transversely isotropic, tilted transverse isotropic) anisotropic velocity model commonly used in industrial production has a long iteration cycle and low iteration efficiency in the modeling process, and the established anisotropic velocity model has a large discrepancy with the actual data. error

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