海洋地质前沿2026，Vol.42Issue(6)：61-73,13.DOI:10.16028/j.1009-2722.2026.015
西湖凹陷强压扭作用下大背斜内差异构造特征及其对油气成藏的影响
Differential structural characteristics and their impact on hydrocarbon accumulation in large anticline under transpression in the Xihu Sag:a case study of the N27 Structure
摘要
Abstract
The central anticlinal belt of the Xihu Sag hosts extensive large-scale,high-angle anticlinal clusters,whose genetic mechanisms and the key factor on hydrocarbon enrichment remain as the exploration targets.Fo-cusing on the largest and most complex anticline within the belt—the N27 Structure,and utilizing the 3D seismic data,we systematically analyzed variations in stratified and segmented structural deformation,and proposed a dual-basement,left-stepping,dextral transpression strike-slip model,from which its structural evolution was compre-hensively interpreted in combination with physical modeling experiments validating the model reliability.In addi-tion,s the N27 hydrocarbon accumulation model was established via geochemical analysis.Results reveal that the N27 Structure exhibits significant intra-structural heterogeneity,and its planar configuration can be segmented in-to three distinct domains:northern segment,central segment,and southern segment.Its evolutionary history com-prises four major tectonic phases:syn-rift extension,fault-depression transition,depression-transpression inver-sion,and post-rift thermal subsidence.The structural deformation was jointly controlled by basement-involved faults and regional stress fields.During the Longjing Movement(5 Ma),the older NE-striking en echelon fault systems underwent dextral transpressive strike-slip deformation,culminating in compressional amalgamation via fault reorganization.Moreover,physical simulation experiments were designed based on the kinematic model yiel-ded robust results,demonstrating high geometric consistency with actual structural features in terms of local struc-tural configuration and critical fracture development patterns,thereby validating the reliability of the proposed model.At last,our integrated analysis of hydrocarbon charging episodes from drilling data revealed that the primary control on localized hydrocarbon enrichment in the N27 Structure was the efficiency in the migration of major fault systems.The southern segment exhibits weaker late-stage fault activity and a larger angle between fault planes and the maximum principal stress direction,resulting in significantly lower hydrocarbon migration ability compared to the central and northern segments.Overall,a multi-episodic,fault-controlled differential accu-mulation model was established for the N27 Structure,in which the central-northern segment was identified as a favorable hydrocarbon enrichment zone.This understanding provides critical guidance for the exploration strategies in the central anticlinal belt.关键词
西湖凹陷中央背斜带/强压扭作用/构造控藏Key words
central anticlinal belt of Xihu Sag/intense transpression/structural control on hydrocarbon accumu-lation分类
海洋科学引用本文复制引用
张伯成,刘春锋,陈春峰,唐贤君,巢越..西湖凹陷强压扭作用下大背斜内差异构造特征及其对油气成藏的影响[J].海洋地质前沿,2026,42(6):61-73,13.基金项目
国家自然科学基金"中—新生代东海含油气盆地差异演变及控制机制"(42430806) （42430806）
