MULTIPLE ATENUATION TO REFLECTION SEISMIC DATA USING RADON FILTER AND WAVE EQUATION MULTIPLE REJECTION (WEMR) METHOD

• Main Author: PUPUT ERLANGGA (nim : 223 07 302), MOKHAMMAD
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/23130
• Institution: Institut Teknologi Bandung

Separation between signal and noise, incoherent or coherent, it is an important thing in seismic data processing. Although we have processed the seismic data, the coherent noise is still mixing with the primary signal. Multiple reflection is a kind of coherent noise. In this research, we will process the seismic data in the hope of attenuate multiple reflection in the synthetic seismic data and the real seismic data of Mentawai. Many kind of seismic processing data methods have been known to attenuate multiple reflection, one of them is Radon filter method that discriminate between primary reflection and multiple reflection in the τ-p domain based on moveout difference between primary reflection and multiple reflection. However, in cases where the moveout difference is too small, so the Radon filter method is not enough to attenuate the multiple reflection. The Radon filter also produces the artifacts on the gathers data. Except the Radon filter mehod, we also use the Wave Equation Multiple Elimination (WEMR) method to attenuate the long period multiple reflection. The WEMR method can attenuate the long period multiple reflection based on wave equation inversion. Refer to wave equation inversion and the magnitude of the seismic wave amplitude that observed on the free surface, we get the water bottom reflectivity used to eliminate the multiple reflection. The WEMR method does not depend on the moveout difference to attenuate the long period multiple reflection, therefore the WEMR method can be applied to the seismic data that have the small moveout difference as the Mentawai seismic data. The small moveout difference on the Mentawai seismic data is caused by the restrictiveness of far offset, that is only 705 meter. In the end of this thesis we will compare the real free multiple stacking data after Radon filter process and the real free multiple stacking data after WEMR process. The conclusion is the WEMR method can more attenuate the long period multiple reflection than the Radon filter method on the real (Mentawai) seismic data.