Abstract: Jinghe Oilfield is located at the junction of three major structural units of the Ordos Basin.It has undergone multiple phases of tectonic activity,resulting in extremely complex fault development.To better understand the fault structural characteristics and evolutionary processes in Jinghe Oilfield and their impact on hydrocarbon exploration,a systematic study was carried out based on detailed structural interpretation of 3D seismic data,integrated with the basin tectonic evolution characteristics and regional geodynamic setting.The fault types,geometric characteristics,differential activity patterns,and genetic evolution of faults in Jinghe Oilfield were comprehensively analyzed.The results show that the study area is mainly characterized by strike-slip faults and normal faults,with clear stratified and segmented differences in fault activity.From bottom to top,an oblique extensional and right-lateral strike-slip fault system has developed in the Lower Paleozoic;a fault system with weakly inherited activity along the main faults in the Upper Paleozoic;and a left-lateral strike-slip inversion fault system in the Mesozoic.The faults in Jinghe Oilfield have undergone five major phases of activity,with the primary active periods being the Caledonian and Yanshan-Himalayan orogenies.The main hydrocarbon accumulation period is the middle-late Early Cretaceous,which aligns well with these fault activities.The Yanshanian orogeny reactivated strike-slip faults in the study area,connecting the Chang 7 source rock interval with the underlying Chang 8 reservoir,which is of great significance for hydrocarbon migration,accumulation,and differential enrichment.This study provides theoretical reference for research on the fault system of Jinghe Oilfield and for guiding exploration practice.

Key words: strike-slip faults, structural characteristics, genetic evolution, Jinghe Oilfield, Ordos Basin