The Kongdian Formation in Wangjiagang structural zone in Dongying depression is complex in structural characteristics

and its tectonic evolution process is still poorly understood.To solve these problems

various data including seismic

logging and core were integrated to analyze the structural characteristics of Kongdian Formation

summarize its regularity of formation and evolution

and reveal the control effect on hydrocarbon accumulation with rose diagram of faults

balanced cross section and fault-sealing analysis methods.The following results were obtained.Most faults were formed in the DongyingKongdian period.Owing to the differences of formation mechanisms

faults with different trends are different in timing and configurations.On plane view

the faults show configurations such as comb-like

parallel or echelon.While on sectional view

they show configurations such as step

"Y" shape or roof-like.Folded belts which were controlled by Tan-Lu fault zone and basement strike slip fault system have undergone three evolutionary stages including formation stage

intensification stage and finalization stage.During this period

the folded belts were cut by earlier or growth faults

resulting in moniliform fault-nose distribution.The structural zone controlled hydrocarbon pooling.It is the most favorable destination of hydrocarbon migration and has better physical properties of reservoir in the axial region than those in two wings.Fault sealing and carrier beds are the key factors controlling hydrocarbon migration and accumulation.The length of fault

the width of folded zone and reservoir physical property determine the plane distribution area of oil/gas

while the fault configuration and amplitude of fold zone jointly control the spatial distribution of oil/gas.