APPLICATION OF FAULT RECOGNITION TECHNIQUE BASED ON MAXIMUM LIKELIHOOD IN EXPLORATION OF QINHUANGDAO 28 OILFIELD

The Neogene fault system in the Bohai area is complex and affected by multi-stage tectonic movements, which makes the structure of the Bohai oilfield very fractured.During the exploration and evaluation process of Qinhuangdao 28 structure, it was found that the fractures in the local area showed a plume distribution in the plane, and there was a falling fault zone. This feature is one of the basis of strike-slip fault, but it is not objective to rely solely on geological theory to determine whether there is a strike-slip fault. It is necessary to use seismic attributes to verify its objective existence. In the process of evaluation, through the combined application and comparative analysis of different technologies, it is found that conventional edge detection, coherence attributes and other techniques are difficult to effectively identify complex faults in this area. In this paper, the median filtering algorithm is used to remove some noise interference, highlight the fracture information, and use the maximum likelihood attribute technique to identify a clear "hidden strike-slip" fracture. Based on the plane features and further analysis of the fault structure, the resources amount increases by about 3 million tons. It has laid a solid foundation for expanding the reserves of Qinhuangdao 28 Oilfield. In the current fine exploration stage, the application of micro-fracture identification technology will further improve the reliability and fineness of fault system interpretation in complex fault block areas, and improve the drilling success rate of oilfield rolling exploration and development.