Characteristics Of Fault And Its Controlling Role Towards Oil-Gas Reservoir Forming And Distribution In Tanan Depression

The characteristics of the faults in Tanan depression are analyzed by using 3D seismic data , the distribution of oil and gas and the reservoir types inTanan depression are researched according to the different fault systerms.The controlling role of faults towads oil and gas are summarized and the pattens of fault-controling-reservoir are established.The two important seismic reflection interfaces, T22 and T04 ,represent the important unconformities,which divided the depression into three tectonic layers,the rift structural belt,the fault sag structural belt and the depression structural belt.The Tanan depression developed two sets of fault systerms based on the geometry characteristics of faults,the upper systerm and the lover systerm.The boundry of the two systerms is Damoguaihe group,the main strike of the faults here is NEE-NE.The combination modes of the upper systerm in the section are mainly v-type, y-type or inversion y-type,and in the plane they exist maily in the form of Braided or parallel combination modes. Tanan depression experienced three great fault-deformation periods,according to the evolution of faults and the geometry characteristics of the faults ,also the deformation times and the deformation styles.On the basis of the division of the fault-systerm,there are three kinds of reservoirs in Tanan depression, tectonic reservoir, tectonic and lithologic reservoir, lithologic reservoir.The controlling role of faults towads reservoirs are reflected in two aspects,respectively are the control function of faults in hydrocarbon migration and the controlling function of faults in the accumulation of oil and gas.With the guidance of thestudy of fault system and reservoir .controlling role,there are two types and three kinds and five sub-types of reservoir-controlling modes.