Multiples Elimination to enhance Seismic Imaging for Safe Wind Farm Establishment: A case study from Baltic Sea

Abstract

The primary objective of this paper is to eliminate the effect of multiples on seismic data using different multiple attenuation techniques, ultimately enhancing seismic imaging for the establishment of wind farms in the study area. Seismic reflection data processing is a highly effective method for detecting potential hazards such as mines and shallow gas bubbles, making it crucial for environmental hazard assessments. In this study, multiple elimination methods were combined to attenuate different types of multiples in 2D raw shallow marine seismic data from the Baltic Sea region. The demultiple workflow combined several robust techniques: Surface-Related Multiple Elimination (SRME), Tau-P deconvolution, high-resolution (HR) radon demultiple, and Common Depth Point (CDP) stacking. SRME was used to remove surface-related multiples by subtracting predicted multiple models from the seismic data, followed by Tau-P deconvolution to attenuate short-period multiples. HR radon demultiple was then employed to attenuate any remaining multiples, which could not be eliminated by previous methods, and finally, CDP stacking of normal moveout-corrected data was applied to improve the alignment of primary reflections and eliminate non-aligned multiples. The improvement in data quality was not solely due to the individual demultiple techniques but from their integration. Each method addresses specific types of multiples and noise, and the combined workflow ensures the optimal suppression of unwanted energy without losing important seismic signal. The final stacked seismic section showed significant improvement in image clarity, confirming the absence of predicted mines or shallow gas bubbles beneath the surface. Based on these findings, the study concludes that the area is suitable for wind farm construction.