METHOD FOR DETERMINING THE PHASE FLOW RATES OF A MULTIPHASE FLOW OF PRODUCED HYDROCARBON Russian patent published in 2023 - IPC E21B47/07 E21B47/107 E21B47/11 

FIELD: hydrocarbon production, qualitative and quantitative evaluation of multi-phase flows in oil wells through distributed measurements.

SUBSTANCE: in accordance with the proposed method, two lines of fiber optic cables are placed along the well interval under study, one of which is single-mode and is a distributed acoustic sensor, and the other is multi-mode and is a distributed temperature sensor. Using reflected signals from a distributed temperature sensor, the basic temperature signal is determined by isolating the low-frequency component of the data received from the distributed temperature sensor. Using reflected signals from a distributed acoustic sensor, the high-frequency relative deformation of the distributed acoustic sensor and the low-frequency variation of the phase of the reflected signal are determined. Based on the high-frequency relative deformation of the distributed acoustic sensor, the total flow rate and the phase composition of the flow are determined. The temperature variations along the cable or over time are determined, and based on the combination of the temperature variations obtained from the low-frequency phase variation of the reflected signal from the distributed acoustic sensor with the basic temperature signal obtained by extracting the low-frequency component of the data received from the distributed temperature sensor, high-precision temperature values are obtained. By hydrodynamic simulation of multiphase flow, taking into account the equality of the total flow rate to the total flow rate determined on the basis of high-frequency relative deformation of the distributed acoustic sensor, the model temperature is determined. High-precision temperature values obtained by combining the basic temperature signal from the distributed acoustic sensor and the low-frequency phase variation of the reflected signal from a distributed acoustic sensor are compared with a model temperature, and as a result of multiple selection of model parameters that provide the best match between the high precision temperature and the model temperature, the distribution of the production rate of each of the phases at each point of the interval under study at each moment of time is obtained.

EFFECT: providing the possibility of determining phase flow rates (water and oil) of a multiphase flow of produced hydrocarbon with a sufficiently high accuracy due to a combination of two measurement systems based on fiber optic cables.

1 cl, 6 dwg