Perpustakaan Digital ITB

This study focuses on optimizing the Matrix Acidizing process in Well Y in Field X, with the Minahaki Formation serving as the productive carbonate limestone layer. This well exhibits a significant positive skin factor of 15, caused by calcite reprecipitation after perforation, which negatively impacts productivity. This research aims to determine the optimum acid contact time and injection rate through the integration of Damkohler Number analysis and simulation modeling.The methodology involves calculating the parameters of 12% HCl acid, then calculating the initial injection rate using a common field-scale equation. Sensitivity analysis is then performed using the Damkohler Number, a dimensionless parameter representing the ratio of reaction rate to transport rate. These Damkohler Number values are then simulated, yielding data on pressure-time curves, wormhole length versus injected volume, and skin changes. Breakthrough (BT), characterized by a sharp decline in the pressure curve and a plateau in wormhole length, indicates the formation of a conductive path. The volume and time to BT are used as key parameters for optimization.The analysis identified four candidate optimum injection rates at Damkohler Numbers of 0.1, 0.12, 0.15, and 0.175, with corresponding injection rates of 1.64, 1.40, 1.09, and 0.94 BPM respectively. Among these optimal candidates, a detailed analysis and comparison of their parameters were conducted to identify the most optimum value.A Damkohler Number of 0.15 with an injection rate of 1.09 BPM was chosen as the optimum injection rate1. This condition required a breakthrough volume of 65.40 bbl, achieved in 60 minutes, and resulted in a wormhole length of 1.42 ft (43.28 cm)2. This choice offers significant volume savings (17% compared to Da 0.1) and a faster breakthrough time while achieving the desired negative skin, indicating effective formation stimulation.