Perpustakaan Digital ITB

The oil and gas industry continues to innovate to meet the energy demand which increase steadily. One of its innovations is Enhanced Oil Recovery (EOR) which act as tertiary recovery to increase oil recovery. Low Salinity Water Injection (LSWI) as one of EOR is considerably more affordable than other method which alter wettability of rocks by injecting low saline water. Multi-component Ionic Exchange (MIE) is believed to be primary mechanism to wettability alteration towards water-wet and is controlled by Cation Exchange Capacity (CEC). Various heterogeneous approaches have been researched to predict CEC value. CEC usually correlated to shale volume fraction (vsh) and its porosity interpretations; this method is considered a simple one. Recently, Clay-typed distribution has been studied. These approaches should affect CEC distribution thus affecting the prediction. Therefore, an investigation toward effect of CEC distribution is a must to understand its effect to LSWI implementation. In this study, reservoir simulation using LSWI method is implemented in a well-to-well model, namely B-4 to B-3 and B-4 to B-5 models of “B” Structure in “S” Field, considering MIE mechanism. Several distributions of CEC including clay-typed distribution and simple CEC correlation created from available data were compared. Sensitivity to the salinity of injection water and injection rate was carried out using 2000 ppm, 4000 ppm, 500 STBD, and 1000 STBD. This simulation increases oil recovery by 3.8 – 16% for model B-4 to B-3 and 1.3 – 3.1% for model B-4 to B-5 on various CEC distribution. It is shown that domination of lower CEC value gives higher oil recovery than the one that have higher CEC value domination. It was also shown that lower salinity resulted in more significant incremental oil recovery. In addition, the injection sensitivity showed that a higher injection would give a higher oil recovery. These findings should give insight to CEC distribution effect to LSWI implementation