Study on the structural characteristics of transtensional faults and their controls on hydrocarbon accumulation is of great significance to the fine reservoir evaluation in the highly-explored areas of eastern China.The genetic model of transtensional faults in the Dongying Depression

Bohai Bay Basin

was studied

and the accumulation model controlled by transtensional faults in this area was established

on the basis of the geometrical and evolutionary characteristics of the transtensional faults.Research shows that

the transtensional faults in the Dongying Depression can be divided into three types

the broom-shaped

en echelon and juxtaposition faults.The broom-shaped transtensional faults are characterized by early extension and later transformation

with the structural style evolving from a single fault to a broom-shaped fault zone.While the juxtaposition transtensional faults feature early transformation and later extension

with its structural style evolving from the en echelon to the juxtaposition type.The en echelon transtensional faults are characterized by simultaneous transformation and extension

with its structural style evolving from a single fault at early stages to the en echelon fault zone.The differential evolution of transtensional faults leads to the model of controls over hydrocarbon accumulation with open-close coupling

providing a guidance for the fine exploration and development of reservoirs in transtensional basins.