Structural Characteristics of First-order Transition Zone and Its Control over Oil and Gas in Gaoyou Sag

The transverse transition zones in Gaoyou Sag were distributed discontinuously in S shape.Seismic and geological data were used to study the structural characteristics of main faults changes along their strikes in Gaoyou Sag.The transverse transition zones used as marks of zone partition were located.Types and characteristics of transverse transition structures at different structural positions were also analyzed.Transverse transition zones can not only dominate the forming environment of the organic matter,but also can form various traps by themselves,it becomes the area of abundant oil and gas enrichment in different sub-depressions.