FIELD: oil production. SUBSTANCE: assay of stratified oil is separated in high pressure vessel at three thermobarometric conditions: at stratum temperature and pressure, at stratum temperature and pressure being lower than this in stratum, but higher than indoor pressure, at 20 C temperature and stratum pressure. Volume of oil being separated, volume of separation gas, weight of oil being separated are determined, and coefficient of isothermic compressibility and volumetric coefficient of thermal expansion are calculated by correlation formula. EFFECT: very effective determination of elastovolumetric properties of stratified oil. 1 tbl
