FIELD: oil prospecting. SUBSTANCE: invention relates to examination of minerals-oil reservoirs by NMR technique and can be used for determining current level of oil in formations. Sample is consecutively placed into two different working solutions, in particular those consisting of protium water and deuterium-rich water, deuterium concentration in the latter being superior to that in the former. Sample is incubated in each solution until amplitude of signal of liquid in sample is stabilized. After each incubation, one measures weight of solution and its signal amplitude and then, using formula, determines equilibrium volume concentration of deuterium oxide in each of solutions. Using thus obtained value, one determines amount of oil in sample according to appropriate formula. EFFECT: reduced consumption of deuterium-rich water and created wasteless technology. 2 cl, 1 dwg, 2 tbl
