With the aim of monitoring the course of development and analysing the distribution of properties of crude oil of the ＇＇White Tiger＇＇ field from operating wells, by means of photocolorimetry, refractometry, IR spectroscopy, gas-liquid chromatography, thermal analysis etc. it has been shown that, with statistical reliability, at least four groups of crude oils characterized by the same type of properties can be singled out. The data obtained are analysed from the point of view of the presence of possible overflows in formations and variation in the properties of crude oil during development.