Publications

Digital mapping and digital outcrop modeling are the current state of the art in geology that incorporated traditional field geological mapping and digital technique. Integration of these two techniques produce a realistic earth model that could help to understand its petroleum prospectivity. Our study aims to provide a workflow and illustrate preliminary reservoir characterization as well as reservoir quality index assessment from mapping and digital outcrop model in the area with lack of subsurface dataset, such as limited well and seismic data distribution due to an early exploration stage. We utilized a mix siliciclastic-carbonate outcrop of Ngrayong formation in the Randugunting Block, East Java, collecting several measuring sections and followed by rock sampling per certain interval. Drone acquisition was implemented in the area of interest to generate high resolution 3D outcrop model. The measuring section later on tied with digital outcrop model, producing structural and stratigraphic model. In addition, subsurface reservoir parameters from well and seismic were integrated in order to add accuracy value to our model from surface perspective. Facies and properties model were populated and Reservoir Quality Index (RQI) was calculated to suggest any potential flow units. Our results show excellent alignment between structural, facies, properties model and reservoir quality index to illustrate characteristic of reservoir in the study area. Uncertainty comes from geostatistical approach, data acquisition quality, and theoritical assumption where multiple sensitivity analyses were conducted to optimize the model. Methodology presented in this study can help to assess the reservoir characterization and quality index in the early exploration stage. Thus, reservoir distribution, potential flow units and petroleum prospectivity will be mostly predictable. In addition, this study has successfully visualized and manifested preliminary 3D subsurface reservoir characterization in area with lack of subsurface dataset and reduced significant capital expenditure cost (CAPEX) for acquisition new data on early exploration phase.