METHOD FOR DETERMINING THE LIMITING PRESSURE AND MAXIMUM FLOW RATE BASED ON THE RESULTS OF CHANGES IN BOTTOMHOLE PRESSURE IN A WELL Russian patent published in 2023 - IPC E21B47/06 E21B47/10 

FIELD: oil industry.

SUBSTANCE: invention relates to the selection and control of the operating mode of a production well, ensuring its maximum flow rate. The method for determining the limiting pressure and the maximum flow rate based on the results of changing the bottomhole pressure in the well includes measuring the actual value of the bottomhole pressure in the well and measuring the well flow rate, determining the limiting bottomhole pressure, regulating the well operation mode by changing the bottomhole pressure. At the same time, the readings of the flow rate and bottomhole pressure are periodically taken during the operation of the well. The bottomhole pressure is reduced by changing the mode of operation of the pumping equipment of the well. The well is brought to a pseudo-steady state and the flow rate and bottomhole pressure are taken again. Next, the well is stopped to determine formation pressure, or formation pressure is used according to previous studies. According to the obtained data on the flow rate and bottomhole pressure in two operating modes, using the given mathematical expression, the extremum of the function is calculated by the Brent method, which is an approximation of three points by a parabola corresponding to the limiting bottomhole pressure. Then, according to the given mathematical expression, the flow rate is calculated taking into account the changing well productivity according to the straight line equation for two productivity points corresponding to two well operation modes. According to the obtained values of the limiting bottomhole pressure, the well is brought to the maximum flow rate or to build correlations for the calculation method for determining the limiting bottomhole pressure.

EFFECT: increased efficiency by simplifying the method for determining the limiting pressure for each well, reducing the complexity and time spent on the implementation of the method by reducing the number of well operation modes, expanding the possibility of using the method for large groups of wells, as well as expanding the range of methods for determining the limiting pressure and maximum flow rate based on the results of changes in bottomhole pressure in the well.

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