基于高斯射线束的叠前深度偏移在断裂带成像中的应用
——以渤海海域辽东湾地区为例

Application of Gauss beam migration in imaging of high and steep angle faulted zone:
A case of Liaodong Bay of Bohai Sea in China

张志军

Zhang Zhijun

中海石油（中国）有限公司天津分公司渤海石油研究院，天津 300452

Bohai Oilfield Research Institute, Tianjin Branch of CNOOC Ltd., Tianjin 300452, China

渤海海域辽东湾地区高陡复杂断裂带是油气聚集的重要区带。该构造具有地层倾角大、断层发育、断层两盘地层速度横向差别大的特点，因此，地震资料的准确成像对合理把握地层产状及正确定位断层尤为重要。传统的地震成像方法由于其自身算法及适应性的限制，在该地区难以准确成像。高斯射线束偏移方法是一种有针对性的射线束偏移方法，该方法利用射线束叠加保留了大部分波至时间，从而克服了标准射线方法在焦散面附近振幅急剧、不固定变化的缺点，在速度复杂构造的地方也能很好地成像，同时该方法具有运算速度快的特点，处理后的地震资料信噪比较好。高斯射线束叠前深度偏移技术在渤海海域辽东湾地区有很好的应用效果，有效地改善了高陡构造和走滑断裂带的地震成像问题，提高了地震资料的信噪比。

The high and steep angle faulted zone located in Liaodong Bay, Bohai Sea, China is an important hydrocarbon accumulation zone. The structure of this specific type has the following characteristics: steep layer, complex fault, and big velocity difference between the two sides of the fault. Accurate imaging of seismic data is very important to the stratigraphic attitude and the location of faults. The conventional seismic imaging method could not get correct imaging because of the limit of its algorithm and adaptability. Gauss beam migration is a specialized beam migration, which preserves most of arrival time through ray-beam stack and can also assure the migration impulse in complex velocity fields with fast calculation and good seismic S/N ratio. Gauss beam migration was applied successfully in Liaodong Bay in Bohai Sea, improved the image qualities of the high-deep structures and strike slip fault zone, and enhanced the seismic S/N ratio.

10.6056/dkyqt201506004