The polyamide (PA-11) is in use since more than 30 years in offshore applications, especially in the manufacturing of the pressure sheath in flexible pipes. This intensive use of PA-11 is due to the very good mechanical properties of this material allowing to bear the mechanical loading imposed to flexible offshore pipes, in particularly for dynamic application. However, the diffusion of gases through this layer has been a concern in relation to the mechanical integrity of the pipe and new materials have been development to decrease the gas barrier properties. In the present study, composites based on PA11/CaCO3, nanoparticle, were prepared by melt mixing in a Teck Tril twin screw extruder with L/D ratio 36 and D=20mm. The commercial PA-11 used was supplied by Arkema (a pipe grade) and the mineral filler was supplied by Lagos Company. A factorial experimental design was used to investigate the influence of the independent variables (n-CaCO3 and screw speed) on the mechanical and rheological properties of the materials. An intermediate level to each factor was also used. The dependent variables analyzed were Young’s modulus, Melt Flow Index (MFI), impact strength and the zero shear viscosity. Previous results showed that the addition of the nanofiller improved the mechanical properties and increased the zero shear viscosity, in the composition range analyzed.