METHOD FOR DETERMINING THE OIL RECOVERY COEFFICIENT IN THE DEPLETION MODE IN LOW-PERMEABLE ROCK SAMPLES Russian patent published in 2021 - IPC G01N23/83 G01N15/08 

FIELD: petrochemical industry.

SUBSTANCE: invention relates to the field of petrochemical industry, it can be used in field and research laboratories for the development of technologies for increasing oil recovery and for calculating recoverable oil reserves and operational control over the development of oil fields. The method involves creating residual water saturation in the sample. The test sample is placed in an X-ray transparent core holder of a filtration plant, the sample is scanned with X-ray radiation (signal from the I_ws detector). Then the pore space of the sample is filled with recombined oil (model of reservoir oil), the sample is scanned with X-ray radiation (signal from the I_ro X-ray detector). After an abrupt change in the pore pressure, the pump is switched to the pressure maintenance mode in the hydraulic system and the fluid coming out of the rock sample is taken - modeling the depletion mode of the reservoir bed. The volume of fluid (oil and gas) coming out of the sample is measured at each stage of the experiment. The collection of the coming out fluid is carried out until the total pumped volume is stabilized, after which the sample is scanned with X-ray radiation. The oil recovery coefficient in the depletion mode for the i-th stage of the experiment and the total oil recovery coefficient for the n stages of the experiment with X-ray saturation control are determined by the dependencies.

EFFECT: increase in the accuracy and reliability of measuring the oil recovery coefficient in the depletion mode for low-permeable samples.

1 cl, 1 tbl, 4 dwg