溱潼西斜坡地震资料“双高”处理关键技术

Key technology of high fidelity and high resolution processing of seismic data in west slope of Qintong Sag

溱潼凹陷西斜坡是岩性、构造-岩性等隐蔽油藏勘探的有利区,具有砂体薄、横向变化快、圈闭面积小、断裂关系复杂等特点。常规地震处理剖面保幅性差、频率低,导致小断层识别困难、地层尖灭线刻画精度低、岩性圈闭不落实。开展以提高地震资料保幅性、提高分辨率为核心的“双高”处理方法研究,构建以保幅去噪、一致性处理、高精度Radon变换法压制多次波、反Q滤波提高分辨率、五维数据规则化及精细速度建模等为主的技术体系,并确定对应的质量控制方法。“双高”处理的地震资料保幅性好、信噪比高,波组产状与地质认识更吻合,目的层主频提高10 Hz,有效频宽拓宽20 Hz,小断层及地层尖灭点较清晰。新处理资料的解释发现了一批有利油气目标。

The west slope of the Qintong Sag is a favorable area for lithologic and structure-lithologic subtle reservoir exploration.Its geological targets are characterized by thin sand body,rapid lateral change,small trap area and complex fault relationship.The problems of poor amplitude preservation and low frequency in conventionally processed seismic data profiles lead to difficulties in identifying small faults,inaccurate description of stratum pinch-out lines,and lack of lithologic traps.Thus,this paper carried out the research on the processing methods which focus on high fidelity of the amplitude preservation and high resolution of the seismic data.A technical system was constructed,which mainly includes amplitude-preserved and denoising technology,consistency processing,high-precision Radon transform method to suppress multiple waves,inverse Q filtering method to improve resolution,five-dimensional data regularization technology and fine velocity modeling technology,and meanwhile,the corresponding quality control method was determined.The results obtained by this method have better amplitude preservation and signal-to-noise ratio,and the occurrence of wave group of the target layer is more consistent with the geological understanding.The main frequency of the target layer is increased by 10 Hz,the effective bandwidth is widened by 20 Hz,and pinch-out points of small faults and strata are clear.New processing of data help to discover a number of favorable oil and gas targets.