开平凹陷10-11复杂构造带低信噪比区地震成像技术研究

Research on Seismic Imaging Technology in Low SNR Region of 10-11 Complex Structural Belt in Kaiping Sag

开平凹陷为已证实潜在富生烃洼陷,开平10-11构造带为主洼内具有隆起背景的复杂断裂构造带,为油气运移有利指向区,现有资料古近系中深层复杂构造带地震成像效果差,已发现油气的含油范围以及潜在的剩余潜力较难落实。提高古近系中深层目标构造的成像品质是本文的核心工作,针对现有资料的实际问题采用以下三项关键技术:①多次波联合建模曲波域匹配衰减技术;②构造约束百分比速度扫描解释技术;③高斯射线束叠前深度偏移技术。通过以上方法的组合应用有效提高了中深层成像的分辨率及信噪比。实际资料应用表明,重处理之后中深层高陡构造和断裂带区构造界面形态清楚、断点清晰,目标区域信噪比提升了40%,为该构造带的进一步精细勘探评价提供了可靠的资料。

Kaiping sag is a potential hydrocarbon-rich sag,and its 10-11 structural belt is a complex fault structural belt with uplift background in the main sag,which is a favorable target area for oil and gas migration.Because of the poor seismic imaging effect of the middle-deep complex structural belt in Paleogene,it is difficult to implement the oil-bearing range and potential remaining potential of oil and gas.Improving the imaging quality of the deep target structure in the Paleogene is the core work of this paper.The following three key technologies are adopted for the practical problems of the existing data:①The matching attenuation technology of multiples in curve wave domain based on multiple joint modeling;②The velocity scanning interpretation technology based on construction constraint ratio;③The pre-stack depth migration technology based on Gaussian beam.The combination of the above methods effectively improves the resolution and signal-to-noise ratio of mid-deep imaging.The application of field data shows that the interface morphology of the middle and deep layer is clear and the break-point is distinct in fault zone,and the signal-to-noise ratio of aim-areas is improved by 40%after reprocessing,which provides reliable data for further fine exploration and evaluation of the structural belt.