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Time-lapse Repeatability Evaluation of a Multimeasurement Towed-streamer System - A North Sea Case Study
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 78th EAGE Conference and Exhibition 2016, May 2016, Volume 2016, p.1 - 5
Abstract
We present a case study comprising a time-lapse seismic (4D) repeatability test in the North Sea using a broadband multimeasurement towed-streamer acquisition system. Repeat acquisition with unchanged parameters and minimal time-lapse enabled various wavefield separation techniques to be evaluated, additionally providing a rigorous test for 3D capabilities. Wavefield separation approaches comprised both dual-sensor (PZ) and full multimeasurement (PZY) approaches. The results show consistently higher spatial resolution in the multimeasurement prestack depth migrated volumes, particularly in the shallow section, but also slightly elevated noise levels, especially in the higher-frequency bands. The 4D difference plots are consistent with respect to the elevated noise, but higher 4D signal leakage is observed on the dual-sensor (PZ) data, also within the main signal bandwidth at the reservoir level. This demonstrates a subtle but consistent uplift in the full multimeasurement data set, extending from shallow to reservoir level, suggesting that processing steps including multiple attenuation and migration benefit from dense spatial sampling, even at depth.