多滑脱构造分析及深层背斜判识  

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

作　　者：陈竹新[1] 雷永良[1] 胡英[1] 王丽宁[1] 杨庚[1] CHEN Zhuxin;LEI Yongliang;HU Ying;WANG Lining;YANG Geng(Research Institute of Petroleum Exploration & Development,PetroChina, Beijing 100083,China)

机构地区：[1]中国石油勘探开发研究院,北京100083

出　　处：《石油勘探与开发》2018年第2期265-274,共10页Petroleum Exploration and Development

基　　金：国家科技重大专项(2016ZX05003-001);中国石油天然气股份有限公司科技重大专项(2016B-0501;2016E-0601)

摘　　要：基于滑脱褶皱正演模型的分析,提出在时间域地震剖面中开展多滑脱构造分析和深层背斜真实性判识的方法,主要包括利用均匀速度场对时间偏移地震剖面进行时深转换、对获得的伪深度域剖面进行构造解释和测量、利用测量的构造起伏面积和深度开展分段相关关系分析。基于构造起伏面积-深度相关关系可开展构造层划分、滑脱面和构造缩短量厘定以及深层构造真假判识。构造起伏面积-深度的分段性是多滑脱构造的典型特征,而面积-深度的线性不相关可指示地层未褶皱变形或存在假背斜构造。在不考虑面积-深度不确定性的情况下,分段的斜率可指示各滑脱构造层的差异缩短量;相邻分段的交点指示了滑脱面与参考面的间距,进而厘定原始时间域剖面中的滑脱面位置。该方法的提出有助于深入挖掘和利用时间域地震资料、明确复杂构造区的地质结构和评估深层勘探目标风险等,在准噶尔盆地南缘和川东褶皱带应用后效果较好。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.

关 键 词：多滑脱构造 背斜 时间域地震剖面 面积-深度法 复杂构造区 准噶尔盆地南缘 川东褶皱带中图 

分 类 号：TE121.2[石油与天然气工程—油气勘探]