Research of numerical indicators for the development of the Asselskaya area of Orenburg oil and gas condensate field using the material balance method

Abstract

The purpose of this work is to analyze and forecast the development indicators of the Assel deposit of Orenburg oil and gas condensate field. To complete this task, a large amount of data is required, which was obtained from the technological development project. The calculation is performed using a program written in the Python programming language. The variables for the material balance equation are given, some of them are calculated using intermediate formulas. The average values of the parameters over the last 15 years of development were chosen as the optimized parameters, since small amounts of cumulative production in the first years of development can lead to a significant error in the calculation of the material balance equation. Also, a comparison was made of the estimated forecast for the development of the Assel deposit with the forecast, according to the state plan, presented in the field development project. The comparison was made on the main parameters: cumulative oil production, annual oil production, oil recovery factor and water cut. For a visual comparison of the calculated parameters, dependency graphs are presented that reflect the forecast made by the material balance method, as well as the forecast based on the data of the state plan. The difference in the behavior of the curves shown on the graphs can be explained by the inaccuracy of the parameters describing the reservoir, as well as the inaccuracy of determining the initial recoverable reserves. This is also affected by the difference in reservoir drawdowns for injection and production wells, proposed in the state plan and in the forecast. Of course, the inaccuracy of the injectivity and productivity coefficients of wells, which were selected based on the estimated volumes of water injection and oil production, also affects. Based on the calculation performed, it can be concluded that it is expedient to further exploit the Asselskaya area of Orenburg oil and gas condensate field with the introduction of a reservoir pressure maintenance system until 2079. According to the forecasts, the water cut equal to 96% will be achieved in 2079, while the oil recovery factor will be 0.427.