Geostatistical Inversion of Spectrally Broadened Seismic Data for Re-Evaluation of Oil Reservoir Continuity in Inas Field, Offshore Malay Basin

The application of geostatistics in seismic inversion techniques has been proven somewhat reliable the delineation reservoir properties and recently attracted attention many geoscientists. However, there are cases where its prediction returned negative results after drilling. In this research, we re-evaluated a Inas Field, whose geostatistical result wrongly predicted sand continuity, resulting spudding dry hole. When is successfully applied, it provides an increase resolution aids continuity. Although method relies more on statistical data from well because limitation resolving thin geologic features, spatial variation parameters still depends data, which often have poor quality. Therefore, to investigate impact bandlimited inversion, harmonically extended bandwidth by applying sparse-layer spectral algorithm data. This increased 80 Hz 180 Hz, tuning thickness reduced 32 m 10 at interval. resultant broadband (180 Hz), as original (narrowband Hz) were both used input build two separate models, respectively. Twenty (20) realizations these models generated, ranked into P10, P50, P90, best case was selected for interpretation. These characterize lithofacies distribution. compared, facies distribution model showed that changed towards location well. efficiently improved characterization process not only producing accurate estimation lateral extent heterogeneities but also generating outcomes help us understand why other analyses target misleading. Contrary popular assumption, discovered effects could affect wrong predictions.