EFFECTS OF COMPLETION FLUID COMPONENTS ON RESERVOIR ROCK MATRIX AND ITS PERFORMANCE FOR WORKOVER APPLICATION

This study investigates the effects of three commonly used completion fluid components Sodium Chloride (NaCl), Potassium Chloride (KCl), and Calcium Chloride (CaCl₂) on reservoir rock matrices, with a focus on their performance during workover operations. The compatibility of these brine-based fluids with sandstone formations was evaluated through a controlled laboratory setup simulating reservoir condition. Key parameters such as brine concentration (5%, 10%, 15%), sand grain size (600 µm and 1.18 mm), and temperature (80°C) were varied to assess permeability changes before and after brine exposure. The results show that KCl caused the least permeability reduction, demonstrating superior compatibility and clay stabilization. In contrast, NaCl led to significant permeability losses due to fines migration and asphaltene precipitation, while CaCl₂ exhibited moderate performance with strong flocculation properties but higher clay interaction. The study concluded that KCl is the most effective brine for mitigating formation damage in clay-rich sandstone formations. These findings provide valuable insights for optimizing fluid selection during workover procedures to ensure long-term reservoir productivity and minimal formation impairment.