Formation Damage Evaluation and Simulation System, is designed to measure the effect on the permeability of reservoir rock samples from various drilling and completion fluids at reservoir pressure and temperature. Core samples are placed in a thick walled Viton sleeve with end-plugs designed to facilitate the introduction of completion acid mixes and to allow insertion of ring spacers for accumulation of filter cake at the upstream end of the sample. Simulated overburden pressure is applied to the sample with a computer controlled syringe pump and differential pressure array to ensure that the correct net confining pressure is maintained as injection pressure increases. Free-piston fluid accumulators are provided to accommodate the fluids required for flow tests. Data acquisition hardware and software logs system parameters including flow rates, pressures, differential pressure, temperatures, overburden pressure and cumulative flow volumes. Normal operating conditions for the system are 10,000 psig confining pressure, 7,500 psig pore pressure and 300 °F temperature.