Non‐Darcy flow often occurs in the near‐well region of a reservoir during injection or production. This flow needs to be characterized and its origins fully understood, as it is critical in reducing well productivity. The Forchheimer equation, which describes fluid flow considering an inertial effect, can be adopted to analyze non‐Darcy flow. In particular, the non‐Darcy coefficient in the equation represents inertial resistance in a porous medium and is an empirical value that depends on the pore geometry and fluid properties. This study investigates the existence of non‐Darcy flow by testing a wide range of flow rates for compressible and incompressible. The difference of pressure squared (P₂²−P₁²) vs. Q_m µ (where Q_m) mass flow rate calculated from the volumetric flow rate set at the injection pump) would generate a straight line, indicating the linear behavior of Darcy flow. However, the test results performed to check the nonlinearity of flow showed that the trend depicted is not linear. Thus, non-Darcy flow behavior exists in the flow rate range used in this experiment. In particular, the data obtained in this experiment better fit a second-order polynomial. One of the assumptions that could justify such a deviation from linearity is that permeability does not change with flow rate. Lastly, the mass flow rate is constant across the core. Still, the volume flow rate can change even threefold (mainly due to different pressure gradients), leading to similar changes in density and viscosity to a certain extent.