Lost circulation during drilling is a persistent challenge that can significantly increase operational costs and lead to technical complications. To mitigate this issue, lost circulation materials (ICMs) are employed to seal fractures and reduce fluid losses. This study investigates the application of quartz particles with varying sizes as an LCM additive to improve the sealing efficiency of drilling fluids. The experimental setup utilized a static testing apparatus designed to simulate fractures of different widths under controlled conditions. The drilling fluid tested was a water-based polymer formulation. Three scenarios were evaluated: (1) the use of quartz particles sized 250-280 microns, (2) particles sized 100 microns, and (3) a combination of these particle sizes. Larger particles demonstrated limited sealing capabilities, achieving a maximum pressure of only 0,7 MPa over 20 minutes, insufficient for effective fracture sealing.