Abstract: In the Rumaila Oilfield of Iraq, severe well leakage frequently occurs during drilling, particularly in the Dammam, Hartha, and Shuaiba formations at the second and third drilling phases, where traditional plugging materials have proven ineffective. To address this issue, a new amide-based swelling particle (YX-II) was selected and evaluated through laboratory tests. The results show that YX-II particles, upon absorbing water and expanding, form a dense plugging structure in leakage channels, exhibiting a high swelling ratio (up to 24 times in clean water) and strong pressure-bearing capacity (up to 3.1 MPa). Additionally, 15 plugging drilling fluid formulations were evaluated under 4 leakage channel scenarios. Field applications in 2024 across 22 wells demonstrate a reduction in average single-well leakage volume to 346 m³, a 34.8% decrease compared to 2023, with significantly improved plugging success rates. The technology effectively resolves porous leakage in the Dammam formation and fracture leakage in the Hartha formation. The study shows that the amide-based swelling particle plugging technology is highly adaptable and effective, providing a reliable solution for complex leakage zones. However, further optimization of the match between swelling speed and construction progress is needed to enhance plugging effectiveness and operational efficiency.