Perpustakaan Digital ITB

The declining productivity of mature fields is a significant challenge, generally caused by formation damage in the near-wellbore zone. Matrix acidizing is an effective method for addressing this issue. This stimulation technique uses acid solutions to dissolve blocking minerals and increase rock permeability around the well. The objective of this study is to quantify the changes in the skin factor before and after acidizing stimulation and to compare these changes with those of other stimulation methods, particularly hydraulic fracturing. The methodology includes inflow performance relationship (IPR) analysis using the Pudjo Sukarno model, skin factor calculations, acidizing design based on Bert's law, and acid solubility analysis using gravimetric and volumetric methods. The stimulation design consists of a pre-flush of 10% HCl at a volume of 43 barrels (bbl) and a main acid of 8:2% HCl:HF at a volume of 61 bbl. This design is calculated to reach a damage zone with a penetration radius of up to 7.37 feet. The evaluation results showed that acidizing reduced the skin factor from +2.4 to -3.8 and increased the maximum production rate capacity (Qmax) from 448.97 barrels per day (BFPD) to 687.57 BFPD. There was also a 53.15% increase in the productivity index (PI). Compared to hydraulic fracturing, which reduced the skin factor to -1.36, acidizing is more effective for medium-porosity carbonate formations where damage is concentrated near the wellbore. This study confirms that a proper acidizing design with the correct acid volume and concentration calculations can significantly improve well performance, making it a more efficient solution than other stimulation methods under similar formation conditions.