裂缝融合分析的窄方位叠前裂缝预测技术

Fracture prediction technology on prestack narrow azimuth data with fracture fusion analysis

熊晓军等基于地震波在各向异性介质与各向同性介质中的AVO差异,提出标准差统计方法进行叠前裂缝预测,裂缝预测结果宏观趋势正确;但由于采用窄方位或单方位地震资料(覆盖次数低),预测的裂缝发育带连片性差。为此,通过改进标准差统计方法的裂缝预测流程,引入裂缝融合分析方法,有效克服了采用窄方位或单一方位数据预测裂缝的缺陷,可以准确表征高角度裂缝发育带的三维空间分布特征。首先采用基于标准差统计的窄方位叠前裂缝预测方法,再引入基于网格聚类分析的裂缝融合技术,最后得到纵横向连续性强的裂缝数据体。对中国N区的海洋窄方位叠前地震资料的应用结果表明,所提方法可有效地表征高角度裂缝发育带的展布特征,与钻井数据符合度高。

Given the amplitude-versus-offset(AVO)difference between seismic waves in anisotropic and isotropic media,Xiong Xiaojun et al.proposed a prestack fracture prediction method based on standard deviation statistics and the macroscopic trends of the fracture prediction results were correct.However,due to narrow-azimuth or single-azimuth seismic data(with low coverage),the predicted fracture zone has poor connectivity.Therefore,the fracture prediction process of the standard deviation statistical method was improved and fracture fusion analysis was introduced.As a result,the defect of using narrow-azimuth or single-azimuth data to predict fractures was overcome and the three-dimensional spatial distribution characteristics of high-angle fracture zones were accurately characterized.First,the narrow-azimuth pre-stack fracture prediction based on standard deviation statistics was adopted.Then,the fracture fusion technology based on grid clustering analysis was introduced.Finally,a fracture data volume with strong vertical and horizontal continuity was obtained.The application results of marine narrow-azimuth prestack seismic data in the N area of China show that the proposed method can characterize the distribution characteristics of high-angle fracture zones.It has a high degree of conformity with the drilling data and is suitable for high-angle fracture zones.