Publications

"The Belanak Field is a producing oil and gas field located in Block B, Natuna Sea. Within the field the late to middle Miocene Arang-3 zone is a secondary gas reservoir, interpreted as a fluvial channel complex with limited lateral sand distribution. An integrated case study of the Arang-3 reservoir model is presented incorporating seismic attribute, well log, and production data. The model was built to improve the prediction of Arang-3 reservoir properties and distribution, and for improved dynamic history matching of the zone. Seismic trace shape attributes calibrated to well data show a good correlation with sand or shale lithologies in the Arang-3 zone. Trace shape classification maps integrated with well log stratigraphic correlations and flattened seismic sections support a fluvial channel complex interpretation for the Arang-3. Modeling the distribution of the channel sand bodies was guided by well correlation and seismic facies analysis. The integrated interpretation of these data was then used to derive net sand maps which were used as trends to guide geomodel facies and properties modeling. After building the conceptual reservoir element distribution model, geostatistical analysis for facies parameter population was conducted. robability distributions for net sand maps and vertical proportion curves for facies distribution variability were also constructed. Uncertainty ranges for additional parameters such as Sw and fluid contact positions were also assessed for volumetric calculations, enabling the model to capture a spectrum of outcomes within the uncertainties of the datasets. Subsequent to building the model, two new wells penetrated the Arang-3 targeting deeper zones. These wells provided blind tests for how the model predicted parameters such as depth to target, gross thickness, and effective porosity in the Arang-3 zone. * Conoco Phillips Indonesia Inc. Ltd. Simulation results provided further quality control for the reservoir model’s ability to history match known production in the zone. The conceptual geologic modeling and rigorous uncertainty analysis are demonstrated to have provided a way to improve the prediction of sand distribution, property distributions (porosity and permeability), and volumetric ranges. Anticipated discrepancies in pressure connectivity between model predictions and observed data will require further analysis and will improve the resolution of the model. "