Implementation And Techniques Of Kirchhoff Reflection Seismic Data Transformation

In recent years, the reflection seismic data transformation theory is widely used in reflection seismic data processing and interpretation of seismic data. This is based on the macroscopic velocity field of seismic data transformation theory is the most basic ideas through migration and migration between various data volume in the series of transformation. There are many kinds of, implement the data transformation methods of the existing theory of data transformation methods mainly include the Kirchhoff type data transformation theory and data transformation theory, the wave equation based on the least squares data transformation theory and so on. Seismic data transformation algorithm based on the theory of the wave equation, while the strong lateral can adapt to variable speed under the condition of seismic imaging of complex geological body, but this method is difficult to overcome shortcomings at the same time, the computational efficiency is very low, the high demands on computer memory. Principle of data transformation based on the least square algorithm is implemented by iterative inversion, although you can very good eliminate excursion of the illusion of/against, but in the process of solving precise Hessian matrix is greatly increased with a lot of matrix calculation data computation and data storage space and reduce the computation efficiency of the algorithm. And based on the ray theory of Kirchhoff type data transformation theory, not only high computation efficiency and easy to implement, and can satisfy most of the conditions of geological structure imaging characteristics and advantages. Kirchhoff type for picture of imaging technology in recent years, research can also see the huge potential in the imaging in structure and lithology.This paper adopts the type Kirchhoff pre-stack depth migration and migration as the tool of seismic data transformation, will go through after preprocessing of the data reflected by the pre-stack depth migration velocity field of the initial macro, to map from time domain to depth domain(imaging domain);Then use the same macro velocity field for pre-stack depth migration, the depth migration image field reflect back into time domain reflection data. According to different application purposes, in the process of migration/reverse migration, also can change the measurement system, the velocity field and the fundamental wave type, get the desired output data. Kirchhoff type data transformation algorithm is the key to offset algorithm with the migration algorithm implementation technology, depending on the migration and migration algorithm is implemented(for output and input) oriented, by choosing the appropriate algorithm can deal with different data volume of data transformation demand, thus improve the computational efficiency, reduce the amount of calculation.Seismic data transformation theory in the application of geophysical data processing involves many aspects, such as offset continuation and migration, velocity analysis, static correction, the azimuth Angle conversion, etc. Can be classified into the category of data transformation. In the data transformation theory and algorithm of Kirchhoff type research foundation, its application to the following respects. First, the data transform technology is applied to offset transform(including the transformation to the zero offset data) in dealing with problems. Through the layered model, Marmousi model and numerical calculation of Lingshui model, both satisfied the migration results. Especially in the transformation to the zero offset data has good application prospects. Second, apply Kirchhoff type data transform technology used in of migration, velocity analysis again. When will come from a group of data is mapped to offset zero offset, the event will be arranged in a straight line. They are arranged in a straight line, not on the same set of pre-stack migration/inversion imaging to set, can give the same type of velocity error information. And through the numerical model of calculation verified the effectiveness of the method. Finally, as a result of the migration and migration imaging conditions implied the sum operation, this sum operation makes effective reflection point the increased energy, random scattering point energy attenuation mechanism of Kirchhoff type data transformation are applied to the random noise suppression, and a numerical example is given. Numerical calculation results show that the data transformation technology can effectively improve the continuity of reflection wave and suppress random noise.