Structural analysis of multi-level detachments and identification of deep-seated anticline

• 作者: CHEN Zhuxin HU Ying LEI Yongliang WANG Lining YANG Geng
• 来源期刊: 石油勘探与开发:英文版
• 学科: 地球科学
• 关键词: MULTI-LEVEL detachments ANTICLINE TIME-DOMAIN seismic section area-height relationship COMPLICATED structure southern JUNGGAR Basin eastern Sichuan FOLD belt
• 年，卷（期）: 2018,（2）
• 页码范围: 281-289
• 页数: 9页
• 分类号: P631.4

摘要

Based on forward modeling of detachment fold, this study presents a method to analyze multi-level detachment structures and identify the authenticity of deep-seated anticlines using time-domain seismic section. The steps include the conversion of the time-migrated seismic image into depth domain image using a constant velocity field, structural interpretation of the depth seismic image, measurement of each structural relief area and each height above reference level, plotting of area-height relationship chart with piecewise fitting etc. The area-depth correlation can help the division of structural sequences, the definition of detachment levels, the calculation of the tectonic shortening, and the identification of deep-seated structure. The segment area-height relationship is a feature of multi-level detachment structures, while little or no linear correlation between area and height is an indicator of non-deformation or pseudo-anticline. Regardless of the uncertainty of area-height relationship, the segment slopes will correspond to the differential shortenings of multi-level detachments, the intersection between adjacent segments will give the height of detachment surface above reference level and then help define the detachment level in original time-domain seismic section. This method can make use of time-domain seismic data to determine the geologic structure of complicated structure areas and assess risks of deep exploration targets. It has achieved good results in southern Junggar and eastern Sichuan areas.