Publications

Outcrop and subsurface datasets have been commonly used for geological model as individual stand-alone project. However, this creates a perspective gap between surface and subsurface where the scale involved can potentially lead to misinterpretation. In this paper,subsurfacemodel was generated by integrating Digital Outcrop Model (DOM), static model simulation, wellbore data and seismic forward modelling to predict internal subsurface configuration within similar depositional settingin Kutai Basin area. DOM allows visualization on 3D sedimentary architecture of spatially amalgamated distal mouth-bar sandstone with gross thickness ranging 8-10 meters, and heterogeneously distributed along a 100-meter-wide outcrop. Static facies modeling was performed on a deltaic system trending relatively E-SE depositional direction. Our model suggests that progradational development seems to be interrupted by transgressive phase of shale deposition, whereas distribution of several single distal mouth-bar deposits are strongly influenced by tidal and river flow. Outcrop impedance model was built by collecting attributes data from published Bongkaran-1 well. The modelling from seismic encountered quite challenging issue to figure out the single distal mouth-bar in the system. Nevertheless, it helped distinguishing between seismic and true stratigraphic pinch-out. Moreover, lateral degradation in amplitude may indicate a lateral change in lithology and facies. The ability of DOM and seismic forward modeling to directly compare outcrops with subsurface has enabled us to improve seismic interpretation and solve the loss of resolution issue within the conventional seismic method. Our study has resulted in enhanced prediction of the sedimentary architecture and reservoir geometry in the deltaic system of Kutai Basin area.