混合域高分辨率Radon变换及其在绕射波分离与成像中的应用  

Hybrid-domain high-resolution Radon transform and its application in diffraction wave separation and imaging

作　　者：罗腾腾 徐基祥[1] 秦臻 孙夕平[1] LUO Tengteng;XU Jixiang;QIN Zhen;SUN Xiping(Research Institute of Petroleum Exploration and Development,Beijing 100083,China;China Three Gorges University,YiChang 443002,China)

机构地区：[1]中国石油勘探开发研究院,北京100083 [2]三峡大学,湖北宜昌443002

出　　处：《石油物探》2020年第6期890-900,共11页Geophysical Prospecting For Petroleum

基　　金：国家油气重大专项(2017ZX05001);中国石油天然气集团公司科技项目(2017D-05006-16)共同资助。

摘　　要：为了充分利用地下小尺度不连续地质体如断层、裂缝、河道、粗糙岩丘边缘等携带的高分辨率信息,利用倾角域共成像点道集(CIGs)中反射波同相轴表现为具有稳相顶点的凹形曲线,绕射波同相轴表现为拟线性的明显差异,发展了一种基于稀疏约束预条件共轭梯度法的混合域高分辨率Radon变换绕射波分离成像方法。该方法首先在传统混合域Radon变换算法中引入预条件算子,然后构造了新的时变稀疏模型权,最后实现了倾角域CIGs绕射波分离与成像。与最小二乘Radon变换方法、频率域高分辨率Radon变换方法相比,该方法的分辨率和精度都明显提高。模型数据和实际地震资料的测试结果表明,基于混合域高分辨率Radon变换的绕射波分离成像方法去除反射波更为干净彻底,并且与常规反射波成像方法相比,该方法能有效改善断层等小尺度地质体的成像质量。The high-resolution information carried by small-scale geological discontinuities in subsurfaces such as faults,fractures,watercourses,and coarse rock boundaries can be fully exploited.In this study,a separation and imaging method of diffracted waves in dip-angle common-image gathers(CIGs)was developed,based on a hybrid-domain high-resolution Radon transform,which is solved by a sparse constrained preconditioned conjugate gradient algorithm.This method uses the morphological differences between reflected and diffracted waves,that is the events of reflection are concave curves with stable phase apex while the diffraction are quasi-linear events,to separate and image diffractions in dip-angle CIGs.First,the preconditioned operator was introduced into the traditional Radon transform in the hybrid domain;then,a new time-varying sparse weight of the Radon model was constructed.Finally,separation and imaging of the diffractions in the dip domain CIGs were conducted.Tests on synthetic and field data demonstrated that,compared with the least-square Radon transform and with the high-resolution Radon transform method in the frequency domain,the proposed method removed the reflections more effectively.The proposed method can improve the imaging quality of small-scale geological bodies such as faults.

关 键 词：高分辨率 RADON变换 倾角域共成像点道集 绕射波分离 绕射波成像 

分 类 号：P631[天文地球—地质矿产勘探]