The Method And Application Of Multiple Attenuation

Multiple problems are prevalent in the seismic prospecting, especially in marine. Due to its complexity, multiple problems have not yet been solved well. As a kind of coherent noise, multiples can reduce S/N ratio of seismic data and disturb the reality and reliability of seismic imaging. So the suppression of multiples is critical important in seismic data processing. Therefore, multiple attenuation research has theoretical and practical significance.Aiming at current research, the paper analyses some problems of multiple attenuation, discusses the cause, classification, kinematic characteristics, wave-field theory, and recognition of multiple respectively, and then discusses some common methods of multiple attenuation from different aspects including the principle, application conditions, advantages and disadvantages, and gives a great deal of application to test. Different from current and mainstream research, a combined multi-suppression's method for multiple attenuation is developed and applied.Multiple attenuation methods can be classified into the filtering methods and the wave equation methods. The former is based on the differences of features or properties between multiples and primaries. By virtue of many advantages such as low cost and easy operation, it can suppress multiples effectively when the assumption is satisfied well. But once the differences are small or no difference, the former may serious injury primaries energy. The latter includes prediction and subtraction of multiples. Because of its algorithm with speed-independent and no or little need for the medium model, the latter is used in SRMA and IMA research. However, it also has many limitations.The corresponding application tests show that, to select appropriate method for multiple attenuation is based on the actual situation of seismic data. When seismic data are in rich in various kinds of multiples, a combined method by optimizing several data-matching methods can suppress all multiples sufficiently while the primaries are kept well.The suppression of multiples in shallow-sea data from eastern china shows that the combined multi-suppression's scheme based on predictive deconvolution inτ-p domain and hyperbolic Radon transform is feasible and effective. The combined scheme has a unique advantage and wide application potential.