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Estimating Saturation Changes from 4D Seismic: a Case Study from Malay Basin
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, IPTC 2013: International Petroleum Technology Conference, Mar 2013, cp-350-00365
Abstract
basin is presented. The reservoir sands under study are deposited during Miocene age and are comprises of intertidal shales, siltstones, fluvio-tidal channel sandstones & minor coals. Base 3D seismic data over the field was acquired in 1996 while Monitor 3D was acquired during 2006. Both dataset were processed implementing PSTM processing workflow using similar parameters. The NRMS value of Base and Monitor dataset was found to be 24 which is quite acceptable for quantitative analysis. Even though utmost care was taken during the processing to maintain the repeatability, there are still minor acquisition footprints observed in the Monitor & Base difference volume. Correlation of Monitor & Base amplitude difference with Pressure Perturbation modeling (MacBeth 2003) suggests that the dominant 4D effect in the area of study is related with the saturation changes due to water injection and production. The 4D analysis workflow implemented for estimating Monitor saturation used Base reservoir model (saturation and porosity), Base & Monitor inversion volumes and ΔSw measured at wells. The workflow used the neural network inferences to predict Monitor Sw. The Monitor saturation model obtained from the proposed workflow is seismically constrained in the inter-well & beyond the well regions. It supplements/supports existing dynamic model in identifying un- swept oil compartment and effective reservoir management.