METHOD FOR DETERMINING THE PARAMETERS OF SUPERCRITICAL WATER INJECTION Russian patent published in 2023 - IPC E21B43/24 

FIELD: oil industry.

SUBSTANCE: methods for stimulation technique. The method for determining the parameters for SCW injection includes: obtaining data on the well structure and thermal properties of well materials for SCW injection; obtaining initial conditions that include steam temperature and pressure that are reached at the outlet of the steam generator, steam dryness for wet steam, coolant mass flow rate, injection time, surface rock temperature, geothermal gradient, thermal conductivity and thermal diffusivity; building a well model according to the obtained data and initial conditions and dividing it into a finite number of elements, while the wellhead corresponds to the model point with a value of 0, and the maximum value of the model point corresponds to the well bottom; determining the thermodynamic parameters of the coolant, the phase state of the coolant and heat loss for each element of the well model sequentially from the wellhead to the bottom of the well and fixing them constant along the entire length of each element of the model, while the elements of the well model are selected in length from 0.1 m to 1 m; determination of the values of temperature, pressure, steam dryness for wet steam sequentially for each element of the model according to the obtained thermodynamic parameters of the coolant and according to heat loss data, while for the model point with a value of 0 the obtained initial conditions are used, for subsequent elements conditions are used, at least values of temperature, pressure and steam dryness for wet steam determined for the previous element of the model; repetition of the previous two stages for certain values of temperature and pressure, which are reached at the outlet of the steam generator until the values of temperature, pressure and dryness of steam at the bottom of the well are obtained, at which the phase state of the coolant at the bottom of the well corresponds to the supercritical state of water. The method for enhanced oil recovery includes SCW pumping into the well at parameters that include temperature and pressure values determined by the above method.

EFFECT: increase in the accuracy of determining the thermodynamic parameters of water and its phase states when moving along an injection well and, accordingly, the parameters of injection of supercritical water SCW, taking into account phase transitions, increasing the efficiency of the method for increasing oil recovery, reducing energy costs, the possibility of lowering the temperature and pressure of injection while maintaining the properties of SCW.

34 cl, 5 dwg, 17 tbl, 2 ex