Análisis de velocidad y corrección normal move out de datos sísmicos por medio del software seismic Unix

Abstract

The present work describes the methodology used to perform the velocity analysis and subsequent normal move out correction (NMO), to seismic data 2D corresponding to a marine line, developed with the free software Seismic Unix (developed in the school of Mines of Colorado).The writing is structured in 6 main parts. The first part was called “Preliminaries”; in which it is explained where the seismic data used have been obtained and the geometry that they have. In the part titled “Seismic Unix”, it describes how is the program interface within the Linux operating system. Also, it shows the terminal in which the commands are executed to carry out the project. Subsequently, the title called “Domain of the CDP” shows the necessary steps that must be executed to sort the data in the CDP domain, prior to the Velocity Analysis. In the next chapter, called “Velocity Analysis”, the velocity peak is performed in a semblance map, based on the number of CDP’s that contain the traces. Next, in the “NMO Correction and Stacking” title, the Stack process of the traces that were analyzed in the previous chapter is carried out. Lastly, in the “Trace Filtering and Final Visualization” chapter, a filtering process is performed in order to obtain an optimal visualization of the stacked traces. The scripts used are based on the demos and the Seismic Unix software manual. For example, for velocity analysis, the script called Velan was used, obtained from the demo folder and modified with the project data. In each code used, it explains the function that it executes.