Wellbore Instability Issue in 12” ¼ Section ( Reduce Wells – Ourhoud Zone )

Abstract

Ourhoud Field is a complex reservoir where wellbore instability frequently occurs in 12’’ ¼ inch section due to challenging geological conditions. Analysis of wells JA-8, JA-9, and JA-10 identified key instability mechanisms and guided the development of mitigation strategies. An optimized mud design by adjusting NaCl concentration and oil–water ratio , was applied in well JA-11, which slightly improved stability but still required hard back reaming. This led to the adoption of slick well reamers in well JA-12. By mastering the synergy between fluid chemistry and downhole tooling, we have transformed the 12 ¼” interval from technical obstacle into a clear path for high performance.