| Based on interpretation of regional seismic sections, this paper researches basin structure and fault structure, and researches basin's forming and evolutionary processes and dynamic mode which combined with subsidence history of basin and analysised deformation sequence of basin and constructed structural deformation field of different period, then reveals structural evolution controlled to migration and accumulation of hydrocarbon. Rsearch indicate that in Bodong and Miaoxi area, basin structures were half-graben of downward broken in NW (NWW) and upward warped in SE (SEE). In Qinnan and Shijiutuo area, basin structures are half-graben of downward broken in NW and upward warped in SE in south segment, are asymmetric graben in middle segment, and are half-graben of downward broken in SE and upward warped in NW in north segment. In Bonan area, basin structures are half-graben of downward broken in N and upward warped in S. In Bozhong area, basin structures were down-warped broken basin in south segment, and are half-graben of downward broken in SEE and upward warped in NWW in middle and north segment. In Bozhong depression, there were four types faults which were early extensional faults, middle strike-slip extensional faults, late strike-slip faults and long-term active faults. There were also six fault systems which were Bodong, Qinnan and Shijiutuo, Bonan and Bozhong extensional fault systems and NNE right-lateral strike-slip and NW-NWW left-lateral strike-slip fault systems. There were three fault active periods in Bozhong depression. First, there formed NNE, NE, closely EW extensional faults and NW-NWW extensional transfer faults during sha-3 member sedimentary period, then, superposed NNE right strike-slip extensional faults and NW-NWW left strike-slip extensional faults during Dongying group sedimentary period. Final, the NNE faults occurred right strike-slip movement which influenced by strike-slip displacement of Tanlu fault zone from Ming-1 member to Quaternary sedimentary period. In Bozhong depression, rifting stage of Paleogene was divided four evolutionary stages which were from Kongdian group to Sha-4 member, Sha-3 member, Sha-1 and Sha-2 member and Dongying group sedimentary period. While, later rifting stage was divided two evolutionary stages which were from Guantao group to Ming-2 member and from Ming-1 member to Quaternary sedimentary period. Structure of prototype basins was different on various evolutionary stages, that were extensional down-warped basin or extensional down-warped broken basin at form Kongdian group to Sha-4 member sedimentary period, were extensional faulted basin at Sha-3 member sedimentary period, were extensional broken down-warped basin at from Sha-1 to Sha-2 member sedimentary period, were strike-slip extensional broken down-warped basin and extensional broken down-warped basin at Dongying group sedimentary period, and were down-warped basin influenced by thermal mantle subsidence cooled and left strike-slip displacement of Tanlu fault zones since Neogene. Characteristics of basin structures and structural evolutions indicate that dominant factors of Bozhong depression's formation and evolution were mantle diapirism, regional tectonic stress field and deep faults. Crustal extension induced by thermal mantle diapirism had bi extension and controlled formation and evolution of extensional fault systems. Regional tectonic stress field and deep faults controlled NNE Tanlu fault zones and NWW from Beij to Penglai fault zones conjugate shear strike-slip structural deformation and formatted strike-slip fault systems. In Bozhong depression, structural evolution controlled migration and accumulation of hydrocarbon. Structural activity formatted faults which provided vertical migration pathway of hydrocarbon. Long-term active faults were effective vertical migration pathway of hydrocarbon. Structural deformation of structural active period strongly controlled trap types. Extensional structural deformation of Sha-3 member sedimentary period formed basal buried-hill and basal fault-block traps. Strike-slip extensional structural deformation of Dongying group sedimentary period formed shear anticline, faulted anticline, fault-block and fault-nose trap and so on. Strike-slip structural deformation of from Ming-1 member to Quaternary sedimentary period formed shear anticline and reversal anticline traps. This paper thinks that Guantao group and Ming-2 member are mainly exploration target beds in Bozhong depression, and indicates that transition salient between Liaodongwan and Bodong segment and between Bongdong and Miaoxi segment of Tanlu fault zones and BZ8-4 structure locating the south of Bozhong sag's western slope are most favorable target areas relatively.
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