摘要:
受多期构造运动的改造作用,南黄海盆地构造复杂、断层发育,海相地层横向变化剧烈,再加上埋深较大、地层间反射较弱等因素影响,常规的叠后偏移技术不能对海相地层精确成像。在分析叠前时间偏移的技术特点及实现过程的基础上,提出了以叠前噪音压制、层间多次波消除、精细速度分析与建模、剩余速度分析、模型优化迭代及Kirchhoff积分法偏移为核心的一套叠前时间偏移处理流程。处理结果表明,深部的中—古生界海相地层的成像效果有了明显的改进,归位准确,断点清楚,深部反射信号的振幅强度、信噪比都得到了提高,为本区下一步的勘探布署工作和油气资源的前景研究提供了有利的证据。
Abstract:
Owing to the multiple tectonic movements, the southern Yellow Sea Basin is very complicated in structures. There are plenty of faults, and the marine deposits vary drastically in lateral direction. In addition to the above, the exploration targets are usually deeply buried, the reflection to the interbeded layers is weak, and the ratio of signal to noise is low. Therefore, the conventional stacking imaging method is not able to make an accurate image for the marine strata. In order to solve this technical problem, we tried prestacking time migration processing, such as prestacking noise attenuation, multiple restraining, remained velocity analysis and modeling, model optimization and the method of prestacking time migration technique based on Kirchhoff integral. Results show that the images of the deep marine strata are obviously improved after the processing. The image features are more accurate and clear in breaking points. The reflections amplitude and S/N ratio in the deep strata are improved. These results provide favorable evidence that the processing is effective for hydrocarbon exploration.
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