Multiple and Coherent Noise Removal from X-Profile 2D Seismic Data of Southern Iraq Using Common Depth Point Muting Procedures and Depending on Madagascar Open-Source Package

Abstract

This article describes how to predict different types of multiple reflections in pre-track seismic data. The characteristics of multiple reflections can be expressed as a combination of the characteristics of primary reflections. Multiple velocities always come in lower magnitude than the primaries, this is the base for separating them during Normal Move Out correction. The muting procedure is applied in Time-Velocity analysis domain. Semblance plot is used to diagnose multiples availability and judgment for muting dimensions. This processing procedure is used to eliminate internal multiples from real 2D seismic data from southern Iraq in two stages. The first is conventional Normal Move Out correction and velocity auto picking and stacking, and the second stage is muting. Many Common Depth Point gathers are tested to select the proper muting dimension, later on; the auto pick for the muted semblance is done for the whole 2D seismic data. The following step is to stack the Normal Move Out corrected data. Differences are calculated between the two stages of the process which greatly help to determine the eliminated multiple locations within the sedimentary secession. This will reduce the risk of interpreting these sequences as primary reflectors spatially within deep thin layers. Madagascar open source package is used in these processing steps. Madagascar open source package is very efficient, accurate, and easy to correct any part of the Python code used in the two stages of processing.