THREE DIMENSIONAL RESERVOIR GEOMODELING FOR RESERVE CALCULATION AND PROSPECT DEVELOPMENT USING PETROPHYSICAL ANALYSIS INTEGRATION AT DNF FIELD, SOUTH SUMATERA BASIN

摘要

The reservoir rock of the DNF Field comprisesrnMiocene limestone. The development plan for DNFrnrequires an accurate geological model. Arncombination of high-resolution, three-dimensionalrn(3D) seismic data with existing wells data wasrnperformed to build a geological framework as thernbasic input for 3D reservoir modeling. Depositionalrnfacies can be a key factor to controllingrnheterogeneity in porosity and permeability.rnBased on core data and well logs, the DNFrncarbonate complex reservoir could be divided intornthree sedimentary facies: packstone, wackstone, andrnmudstone. The deagenetic process in the DNFrncarbonate plays an important role in reservoirrnquality because diagenesis processed actively inrncarbonate reservoirs leads to radical changes inrnporosity and permeability, or commonly becausernthe reservoir has a high heterogeneity. Based on therncharacter of the Gamma Ray (GR) log, the reservoirrnBatu Raja Formation (BRF) can be divided into sixrnlithological units limited by the presence of shalernbreaks (marker beds) in some places. The lithologyrnof the upper unit (units 4 to 6) is a rock reservoirrnwith the distribution of porosity and permeabilityrnrates varying, where the bottom of the lithologicalrnunits (units 1 to 3) are in the form of carbonate rockrnwith very tight porosity. The water saturation wasrndetermined from the permeability of the reservoirsrnthrough the Archie equation, and the values werernwithin the range 0.1–100 mD. The type of porosityrnranged from 5–25%.rnThe integration between petrophysical analysis andrnpetrophysical modeling predicted the porosityrndistribution. Eventually, a 3D reservoir model wasrnachieved through the integration of a structural andrngeological framework with petrophysical evaluationrnresults. The realistic reservoir model is essential for future development and improves the confidencernlevels of the original estimates.