渤海海域QHD33-1S低幅构造速度异常分析与应用研究

Analysis on Velocity Abnormality of QHD33-1S Low-amplitude Structure in Bohai Sea:Its Application and Study

在渤海海域石臼坨凸起浅层不同程度地出现了速度异常问题,主要表现为时间剖面与深度剖面上地层不符甚至矛盾的现象。以QHD33-1S构造区为例,首先通过正演模型分析指出速度异常产生的主要原因是砂地比的影响,进而探索提高速度精度和速度异常认知程度的技术方法,从而更准确地把握研究区速度的横向变化趋势。实际应用结果表明,通过对速度异常的准确认识,不仅实现了对目标区低幅构造形态的精细刻画,而且对砂体含油气性进行了有效预测,同时对海上其他低幅构造区勘探有着一定的推广意义。

There existed a problem of different velocity abnormalities of shallow layer in Shijiutuo Swell of Bohai Sea,it presented as disagreement in time and depth profiles and even contradiction.By taking QHD33-1SStructure for example,and by the analysis of forward modeling,it was pointed out that the major cause of the velocity abnormality was the influence of ratio of sandstone and formation thickness,consequently the methods were discussed for enhancing accuracy of velocity and the understanding of the velocity abnormality for the purpose of establishing the trend of lateral velocity variations in the studied area.The application result indicates that by accurate understanding of the velocity abnormality,the low-amplitude structural shape is accurately described in the target area and gas-containing property of sand body is predicted,at the same time it can be popularized to the other low-amplitude structural areas of offshore oil and gas exploration.