Analysis of the field test results for inputs to the ventilation simulation model was performed in the conditions of an operational oil shale mine in Estonia. The oil shale mine uses a very sophisticated ventilation system to provide enough airflow to the eight operational areas with a radius of about 5-6 km. The main purpose of the field tests was to obtain data about ventilation simulation processes that could be useful for improving ventilation efficiency and optimizing related costs. Field tests included measurements of airflow and the fan pressure at different cross sections of intake air through the ventilation shaft. Measurements of airway friction factors were made during the ventilation surveys to determine characteristic friction. factors for the intake airway. The results of measurements can be used for constructing the mine ventilation simulation model required to design a ventilation system in operating oil shale mines.