Based on high-resolution seismic data,complemented by field photographs,joint data,and other information,this study employs fault-related folding theory.to systematically analyze the structural characteristics of Wulong syncline.It further reconstruts the stress sequence of the area and using Hujiayuan fault within Wulong syncline as an example,discussed the impact of SN-oriented structures on the preservation conditions of shale gas in the research region.Wulong syncline is divided into three structural layers:the basal structural deformation layer governs the overall morphology of the overlying strata;the lower structural deformation layer primarily features NE-oriented thrust faults;while the middle structural deformation layer locally exhibits fault-bend fold morphologies.The primary forms of the middle and lower structural deformation layers within the Wulong syncline have been significantly modified by the SN-oriented Hujiayuan fault.During the Mid-Yanshan period,under NW-oriented compressional stresses,the original Wulong syncline gradually formed.In the Late Yanshan period,influenced by sinistral wrenching under EW-oriented compressional stresses,the SN-oriented Hujiayuan fault was created,dividing the original Wulong syncline into eastern and western zones.Among these,the Huolu syncline in the east experienced severe disruption of its shale gas-trapping structures,whereas the western Wulong syncline underwent milder structural alterations,exhibiting stronger structural closure and thus favoring shale gas accumulation.Consequently,the western Wulong syncline represents a primary target for future exploration endeavors.
维普
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