Effects of Completion Fluid Components on Reservoir Rock Matrix and Its Performance for Workover Applications

• Gbenga G. OSEKE

  Author

• Fatima A. SHEHU

  Author

• Muhammad K. ABBA

  Author

Formation damage from incompatible completion fluids remains a major challenge during workover operations, causing permeability impairment and reduced well productivity. This study investigates the effects of Sodium Chloride (NaCl), Potassium Chloride (KCl), and Calcium Chloride (CaCl₂) on sandstone reservoir matrices. Compatibility was evaluated using a laboratory sand-pack flooding apparatus. Brines were formulated at 5, 10 and 15 wt% and injected through fine (600 µm) and coarse (1.18 mm) sand packs at 80 °C; permeability was measured before and after exposure using Darcy’s law. KCl produced the lowest average permeability reductions (3.2–12.9 %), NaCl the highest (13.5–33.3 %), and CaCl₂ intermediate values (13.2–34.1 %). KCl showed superior clay stabilization and minimal fines migration, while NaCl caused greater losses through weaker ion exchange and fines mobilization. CaCl₂ exhibited moderate performance with flocculation benefits but higher interaction in fine packs. KCl is recommended as the most effective brine for mitigating formation damage in clay-sensitive sandstones during workover operations.

• 21_Oseke et al. (2026)

Copyright (c) 2026 Gbenga G. OSEKE, Fatima A. SHEHU, Muhammad K. ABBA (Author)

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