| 講演要旨(和文) | | SRME(Surface-Related Multiple Elimination)とPRT(Parabolic Radon Transform)は,海域の反射法地震探査における主要な多重反射抑制手法である.本講演では,これらの手法解説と,実記録に対する適用結果の比較と考察を行う.比較の結果,3D-SRMEはNearないしMiddle-offsetの記録に対して多重反射抑制効果が高かった.また3D-SRMEはディフラクション型多重反射波や1次反射波との速度差が小さい多重反射波に対して抑制効果が高かった.一方PRTは,Far-offsetの記録に対して多重反射抑制効果が高く,深部構造のイメージングに重要な役割を果たすと考えられる.まとめると,3D-SRMEとPRTは補完的な関係にあるため,3D-SRMEを適用した後PRTを施すことが最も効果的であると言える. |
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| | 講演要旨(英文) | | In recent years, several new techniques have been developed for multiple attenuation. SRME, Surface-Related Multiple Elimination, is a real technological breakthrough and extended to 3D acquisition geometry data without any a-priori information such as the geometrical spreading factor or source signature. PRT, Parabolic Radon Transform, is widely accepted technique for long-period multiple attenuation. Using real 3D data, we re-evaluate the cascaded processing sequence and applicability of these methods. 3D-SRME precisely works for the cases where the moveout difference between primaries and multiples is relatively small, or the diffraction multiples are predominant. Near- to middle-offset multiples in particular, are better attenuated with 3D-SRME than with PRT. On the other hand, PRT works nicely on far-offset range which is required for the imaging of deep target. In conclusion, 3D-SRME and PRT should be complementary approaches. 3D-SRME followed by the subsequent PRT shows excellent results for the attenuation of long-period multiples, and accommodates the complexity of the multiple generator and out-of-plane effects. |
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