Diffraction-based stacking for enhanced acoustic reflection imaging logging

Abstract

High-resolution imaging of near-wellbore geology using acoustic reflection imaging logging (ARIL) is critical for delineating the subtle faults and thin beds that control the distribution of oil and gas resources. However, the sparse receiver arrays in downhole tools yield data with a low signal-to-noise ratio (SNR), and conventional reflection-centric processing workflows typically discard the valuable, wide-aperture energy carried by diffractions. Here, a diffraction-optimized stacking method is introduced. The method constructs a wide-aperture stacking gather based on diffraction theory and Huygens’ principle to more effectively utilize the diffracted energy beyond the first Fresnel zone. To improve the SNR of the diffraction gather, a travel-time correction operator, derived from diffraction kinematics, is applied to flatten the event during the stacking process. This method presents a robust and direct way for converting sparse, noisy acoustic data into high-fidelity images by leveraging higher data redundancy. Validation on synthetic datasets demonstrates a more than threefold increase in stacking fold, resulting in a significant improvement in SNR and enhanced structural delineation. The application of the method to the Sichuan Basin’s complex reservoirs effectively reveals structural features and improves the event continuity of key layers. This approach not only establishes a foundation for more reliable reservoir characterization but also offers crucial methodological support for developing deep oil and gas resources, including well placement and fracturing guidance.