Perpustakaan Digital ITB

Matrix acidizing is a cost-effective method used in petroleum industry by pumping acid and other fluids to remove near-wellbore formation damage and increase well productivity. Skin factor is measured through well test analysis before and after the treatment, and continuous monitoring can provide valuable insights. This study focuses to model skin evolution using three different skin factor calculation methods, Paccaloni method, Prouvost & Economides method, and Hill & Zhu method. Source of the model is two treated zones in “N” and “K” limestone formations with depth range from 6975 ft to 7310 ft. Parameters from well test and few assumptions are used as input for the skin evolution model. The skin evolution model then is used to predict skin factor of three different zones in “K” and “T” limestone formations with depth ranges from 6405 ft to 6615 ft. The practicality and reliability for each method is then assessed as reference for future use. The results of this study shows that the different methods have given out a similar result in skin factor and skin evolution. Skin factor value deviation is affected by permeability thickness (kh) and skin evolution is matched. Higher permeability thickness of 1210 mdft is highly deviated by 127 to 136 and lower permeability thickness of 76.5 mdft slightly deviated by 3 to 11 from well test references. Skin evolution prediction results for the untreated zones produces a very high initial skin factor of 4159, 1563, and 355 with steep decrease on early injection rates. The analysis of this study can be used to determine the optimum point where the matrix acidizing job ends and which method is the most practical to use in field.