3D SEISMIC IMAGE QUALITY STUDY WITH VELOCITY ANALYSIS RESULTED FROM NMO, DMO, AND CRS METHOD

• Main Author: Tabina Joebhaar, Diya
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/53214
• Institution: Institut Teknologi Bandung

Reflection seismic data processing aims to produce image of Earth’s subsurface layers. A series of steps and various processing methods are carried out in hopes of increasing signal-to-noise ratio in order to produce the most representative subsurface image. Some important steps in reflection seismic data processing are stacking and migration. There are three stacking methods that were used in this research, which are Normal Moveout (NMO) and Dip Moveout (DMO), both are forms of conventional stacking method, and also Common Reflection Surface (CRS) stacking method. These three stacking methods are carried out using velocity analysis resulted from its respective method. After the stacking process, the results of NMO, DMO, and CRS velocity analysis were also used for Kirchhoff prestack time migration (PSTM) process. These three methods will be tested to see which one of these methods can produce the best seismic image. The data used in this research is 3D synthetic seismic data of Gulf AK model. Because this model has a subsurface structure with significant dipping difference, the CRS method is expected to produce better seismic cross section. This is because CRS method uses three different stacking operators while conventional method only uses one. These three stacking operators are all affected by the dipping of the reflector. Comparative analysis of the stacking results will be assessed qualitatively based on their velocity semblance, their final seismic cross section, extracted wavelet, and the amplitude spectrum.