Abstract:

 Huangqiao area is situated at the ramp zone in the Lower Yangtze region, which was subjected to multi-staged tectonic deformation events, and preserves complete Mesozoic-Paleozoic marine sediments, which contain multiple sets of source rocks, with fine prospects of petroleum exploration. Based on the detailed structural interpretations of the 3-D seismic profiles in Huangqiao work area and forward kinematic modeling, this paper analyzes its structural deformation characteristics and the deformation processes. The middle-upper Paleozoic and lower Mesozoic strata developed several fault-related folds by forward propagation, then formed the fault-related folding in the opposite direction in the structural front under the effect of the SE-NW regional stress in the Huangqiao area, which shaped the face to face verging structures at the middle and northwest of Huangqiao area and resulted in the strong uplift and denudation. The total structural shortening rate exceeds 47.55% on the regional cross section in this study. Then the regional stress transferred to NW-SE-trending extension, as a result of which there developed some negative inversion faults in the southeast of the work area and the inversion amount increased from the southwest to the northeast of the work area. This extensional event led to the fault back-slip, forming the half grabens which were filled with the upper Cretaceous strata, and causing some damages to the face-to-face structures. Combining previous research achievements of hydrocarbon accumulation, this paper discusses the Huangqiao structural deformation and its relationship to the oil and gas accumulation, and proposes the anticline at face to face verging structure, its footwall and the anticlinal Guangling structure in the southeast of Huangqiao area as the favorable oil and gas blocks. Therefore, the study of the structure in Huangqiao region, can not only help better understand the deformation characteristics and evolution history of Huangqiao structure, but also provide clues for the oil-gas exploration and development.

Key words:  Huangqiaoarea;seismicprofiles;structuralcharacteristics;inversionstructure;forwardmodeling;oilandgasexploration