PRE-STACK DEPTH MIGRATION WITH KIRCHHOFF METHOD ON ANISOTROPY MEDIUM VTI (VERTICAL TRANSVERSE ISOTROPY)

• Main Author: (NIM : 10212018), ADRIANDI
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/20772
• Institution: Institut Teknologi Bandung

Seismic reflection is a method that can produce high accuracy and high penetration range in the exploration of hydrocarbons. Nevertheless, problems can occur when the data signal reflections generated is not appropriate. This occurs due to the slope of the points of reflection on the position of the actual reflection. Seismic data migration process can be used to calibrate the reflector to the actual position. However, errors may occur due to incorrect assumptions that do not correspond to actual conditions. Most seismic data processing assumes that the earth layer is a layer of isotropy, when in reality the earth layer has a structure that changes the wave velocity. Such changes can occur due to the condition of the complex subsurface geology that changes with the facies of a layer. At these conditions of lithology, the speed of seismic waves will change in considerable amount. <br /> <br /> <br /> One method that can be used to handle such complex structures are anisotropy pre-stack depth migration (PSDM). Anisotropy pre-stack depth migration is used based on the assumption that which the waves are going through has Vertical Transverse Isotropy (VTI) properties. This medium assumes that the anisotropy only occurs in vertical degrees, not in horizontal degrees. This method is a method of pre-stack depth migration which adds Thomsen anisotropy parameters such as delta and epsilon. These parameters are later used to analyze the effect of anisotropy from the layers of structure. <br /> <br /> <br /> The advantages of the anisotropic pre-stack depth migration compared by the isotropy pre-stack depth migration are longer offset and better imaging. Longer offset can produce lot of subsurface information and the sharper results of seismic section compared to the gather obtained in isotropy pre-stack depth migration.