Publications

The reservoir rock of the DNF Field comprises Miocene limestone. The development plan for DNF requires an accurate geological model. A combination of high-resolution, three-dimensional (3D) seismic data with existing wells data was performed to build a geological framework as the basic input for 3D reservoir modeling. Depositional facies can be a key factor to controlling heterogeneity in porosity and permeability. Based on core data and well logs, the DNF carbonate complex reservoir could be divided into three sedimentary facies: packstone, wackstone, and mudstone. The deagenetic process in the DNF carbonate plays an important role in reservoir quality because diagenesis processed actively in carbonate reservoirs leads to radical changes in porosity and permeability, or commonly because the reservoir has a high heterogeneity. Based on the character of the Gamma Ray (GR) log, the reservoir Batu Raja Formation (BRF) can be divided into six lithological units limited by the presence of shale breaks (marker beds) in some places. The lithology of the upper unit (units 4 to 6) is a rock reservoir with the distribution of porosity and permeability rates varying, where the bottom of the lithological units (units 1 to 3) are in the form of carbonate rock with very tight porosity. The water saturation was determined from the permeability of the reservoirs through the Archie equation, and the values were within the range 0.1–100 mD. The type of porosity ranged from 5–25%. The integration between petrophysical analysis and petrophysical modeling predicted the porosity distribution. Eventually, a 3D reservoir model was achieved through the integration of a structural and geological framework with petrophysical evaluation results. The realistic reservoir model is essential for future development and improves the confidence levels of the original estimates.