METHOD OF INTERWELL TRACER TEST WITH A LOW DETECTION LIMIT CONTAINING SODIUM OR POTASSIUM SALTS OF 2,4- OR 3,5-DINITROBENZOIC ACIDS Russian patent published in 2023 - IPC E21B47/11 

FIELD: oil industry.

SUBSTANCE: possibility of use in monitoring the development of an oil field. The claimed method of interwell tracer test with a low detection limit containing sodium or potassium salts of 2,4- or 3,5-dinitrobenzoic acids is carried out as follows. The sodium or potassium salt of 2,4- or 3,5-dinitrobenzoic acid is obtained by mixing 2,4- or 3,5-dinitrobenzoic acids with sodium or potassium hydroxide at a mass ratio of 1:1 and then dissolving in water to a concentration depending on the reservoir conditions. Water-soluble and distributable tracers are pumped into the injection well. A sample of produced water is taken from a production well at regular intervals. The concentrations of water-soluble and distributing tracers in the produced water sample are determined by high-performance liquid chromatography with UV detection. Build a cross-plot of concentrations of water-soluble and distributed tracers in the sample of produced water taken from the production well, from time. Then, based on the time values corresponding to the maximum concentrations of water-soluble and distributing tracers in the produced water sample, and the distribution factor of the distributing tracer, the residual oil saturation is calculated.

EFFECT: reduction of the harmful effects on the environment of the fluid injected into the reservoir containing the tracer, in accordance with toxicological requirements.

1 cl, 4 dwg