Operational features and methods for determining the optimal operation parameters in fractured reservoirs with a gas cap: oil rims of Orenburg OGCF case study

The paper deals with the features of well operation at the Eastern part of Orenburg oil and gas condensate field (OGCF). We propose a complex approach to determining the parameters of the fractured formation: based on the mathematical model of Warren–Root fracture reservoir, we find the dependence of the well flow rate on time and parameters of fracture under conditions of maintaining constant bottomhole pressure. Next stage is an extrapolation of this problem for the case of arbitrary dynamics of flow rates and pressures based on the deconvolution theory. The search of parameters of double fracture formation is carried out by their variation in the corridor of admissible values in order to minimize the deviation of the calculated flow rate relative to the true one. To identify possible reasons for the decline in well productivity with a decrease in bottomhole pressure, numerical experiments were performed on synthetic hydrodynamic models to determine the main influencing factors that can lead to an observed decrease in well productivity with increasing depression. Based on the information received, multivariate calculations of sector models of the EP OGCF were carried out in order to determine the optimal operating parameters to maximize oil production or minimize specific operating costs, taking into account the identified complicating factors.

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