digilib@itb.ac.id +62 812 2508 8800

Mature field optimization has been one of the significant activities that there have been various ways proposed to maintain well production and extend its life. One common way that is considered as a promising option is workover – well service (WOWS) activities in order to repair existing production wells for restoring, prolonging, or enhancing the production of hydrocarbons with or without production zone interval changes. In WOWS method, particularly kerja ulang pindah lapisan (KUPL) on mature oil fields, water cut is one of the important considered parameters. In this study, RCAL data will be processed with Hydraulic Flow Unit – rock typing concept with the reservoir characterization by discrete rock type (DRT), resulting in several rock types. Integration with SCAL data will be done to construct a relative permeability model with Corey correlation application, leading to a fractional flow model for each rock type of the reservoir’s identified formations. The fractional flow model will be validated with available well historical data. The result is that it is feasible to estimate water cut of new or existing perforation zone intervals for potential WOWS wells consideration. A fractional flow curve (fw Vs Sw) is representative to the specified formation of the reservoir when comparisons between estimated water cut from the model and well historical data results in a reasonably good match. It was observed that the proposed methodology with the resulted model is significantly reliable to estimate water cut data.