The Research Of Main Fracture Characteristics And Petroleum Geologic Condition In South-central Section Of Liaohe Eastern Sag

By describing the features and period of development of the faults, the paper detailed analyzes the evolution of south-central of Liaohe eastern depression that has experienced in repeated rift, tensile, compression, uplift, erosion and strike-slip deformation. Recognizing that episode of the nature and intensity of fault activity controlled the evolution of sedimentary of clastic rocks in the study area. Different sedimentary facies developed in different periods of structural evolution. The structural evolution in controlled formation of the deep of the basin. The very thick dark mudstone provides the conditions of oil source; alluvial fan and river facies developed in late Es3 period; fan-delta and lake facies developed in Es1 period; western sediment deposited to the east which formed multiple massive fan-delta sedimentary. Multiphasic faults controlled the deposition system which controlled the development of clastic reservoir. Braided river and braided river delta deposition mainly developed in shelving, while the alluvial fan and fan-delta developed in steep slope zone; lake, delta, river and turbidite fan mainly developed in the center of the depression.Magmatism controlled by fracture shows up as widely multi-phased magma intrusion and volcanic eruptions. By sampling and analysing systems biological, the paper takes scheme classified by cycle, period and lithofacies. Igneous was distinguished to basic-neutral-basic cycle, and the eruptionstage of the second cycle igneous rock(trachyte) was refined three turns to research. Analyzing a great deal of data, the type of igneous reservoir spaces include porous, fractured and porous-fractured. Considering the facies, physical properties, capacity, fracture development and other factors, igneous reservoir was divided into four categories based on core observation, lithofacies analysis, logging reservoir prediction, seismic reservoir prediction.Studies suggest that the plane and vertical distribution of oil and gas in Cretaceous-Paleogene are closely related to the faults activities. The faults activities effectively control the formation and distribution of oil and gas reservoirs by effecting the distribution of source rocks, improving reservoir space, forming of the trap and the transporting of oil and gas.