基于Sobel算子级联地震属性的三角洲沉积相边缘识别

Identification of deltaic sedimentary facies boundary based on cascade seismic attribute analysis of Sobel operator

地震属性分析是砂体预测和沉积相表征的重要方法,但在沉积相带边缘薄层发育区对相带边界识别常存在较强的主观性,刻画不够准确。探讨了如何利用基于Sobel算法的边缘检测对地震属性进行级联处理构建地震级联属性,用以提高三角洲相边界刻画精度,并将基于Sobel算子级联地震属性分析方法在南海惠西南地区新近系典型三角洲沉积地层中进行沉积边缘识别应用。结果表明:①利用Sobel算子对地震属性图像进行边缘检测,能够锐化地震属性中的相带边界,提高三角洲沉积体边缘的识别准确性;②对地震属性图像的边缘检测处理会弱化三角洲整体发育形态的规律性,需要将处理前后的地震属性结合起来解释,才能有效刻画三角洲沉积体。此研究为沉积相分布的精确刻画提供了有效指导。

Seismic attribute analysis is an important method in sandstone prediction and sedimentary facies characterization,but the identification of facies zone boundary often has strong subjectivity and the description is not accurate enough in the thin layer developed area on the edge of sedimentary facies zone.This paper discussed how to use the edge detection based on Sobel operator to construct the seismic cascade attributes by the cascade processing so as to improve the precision of delta facies boundary characterization,and the cascade seismic attribute analysis method based on Sobel operator was applied to the identification of sedimentary edges in the typical Neogene delta sedimentary strata in southwestern Huizhou Sag of the South China Sea.It is concluded that:①Edge detection of seismic attribute images using the Sobel operator can sharpen the depositional facies boundaries in seismic attributes and improve the recognition accuracy of delta sedimentary edge.②The edge detection processing of seismic attribute images will weaken the regularity of the overall development morphology of the delta,so it is necessary to combine the seismic attributes before and after the processing comprehensively to effectively characterize the delta sedimentary bodies.This work provides an effective method for the accurate characterization of sedimentary facies distribution.