渤海湾海陆过渡带Q叠前深度偏移方法

渤海湾盆地南堡凹陷海陆过渡带的地下构造复杂，由于地表及地下黏弹介质吸收，导致地震波能量衰减严重，造成地震信号强度和频带宽度的损失，为了提高成像精度，需要补偿地震波能量在地层中的衰减。反Q滤波和时频分析方法没有考虑地震波的传播路径，然而实际地震波的能量衰减是与传播路径密切相关的。为此，采用基于Kirchhoff叠前深度偏移的地震成像方法，在偏移过程中考虑了沿不同路径传播的地震波能量衰减，从能量归位和衰减补偿两方面提高偏移成像质量。应用Q叠前深度偏移，利用Q层析方法获得了Q模型，基于Q模型进行Kirchohoff叠前深度偏移成像，有效补偿了振幅、校正了相位畸变，提高了深部数据的信噪比、保真度及构造解释精度，为叠前反演、岩性识别和流体检测提供了可靠依据。

Study on Q pre-stack depth migration method in sea-land transition zone in Bohai Bay Basin

The sea-land transition zone in Nanpu Sag of Bohai Bay Basin has a complex surface structure. As surface and underground and viscoelastic media are absorbed, the seismic wave energy is seriously attenuated, which results in the loss of seismic signal strength and frequency bandwidth. In order to improve imaging accuracy, it is necessary to compensate for the attenuation of seismic wave energy in stratum. Inverse Q filtering and time-frequency analysis methods fail to consider the propagation path of seismic waves, but the energy attenuation of actual seismic waves is closely related to the propagation path. Therefore, the seismic imaging method based on Kirchhoff pre-stack depth migration is adopted. In the migration process, the energy attenuation of seismic waves propagating along different paths is considered, and the migration imaging quality is improved in terms of energy localization and attenuation compensation. In addition, Q pre-stack depth migration is utilized, and a Q model is obtained by using the Q tomography method. Furthermore, Kirchhoff pre-stack depth migration imaging is performed based on the Q model, which effectively compensates for amplitude and corrects phase distortion, improves the signal-to-noise ratio, fidelity, and structural interpretation accuracy of deep data, and provides a reliable basis for pre-stack inversion, lithology identification, and fluid detection.