METHOD OF DETERMINING OIL SATURATION PRESSURE WITH GAS Russian patent published in 2019 - IPC E21B47/06 G01L9/00 

FIELD: physics.

SUBSTANCE: method is implemented at wells equipped with electric-centrifugal pump (ECP) and frequency converter of electric current of submersible electric motor. By means of two pressure sensors located at fixed distance from each other, in downhole zone from downhole pump to productive oil bed there performed is pressure measurement at various modes of ECP operation. Pressure sensors are connected to power supply line with feedback function with well control station. At the first stage, using a frequency current converter, pressure in the sensor zone is higher than P_sat, it can be judged from stabilization of pressure difference between two sensors. At the second stage of the measurements, the ECP efficiency is considerably increased above the fluid inflow from the formation, as a result the pressure between the sensors decreases below the oil saturation pressure with gas, the first bubbles of gas are separated from oil, its density is markedly reduced. Value of gas saturation pressure with gas is determined by graph of dependence of pressure difference between sensors on mean value of their readings with considerable change of ECP efficiency towards reduction or vice versa.

EFFECT: described is method of determination of oil saturation pressure by gas P_sat in downhole zone.

1 cl, 2 dwg