Application of hydrodynamic simulation on the basis of a composite model to improve the efficiency of gas-condensate reservoir development

At the moment, the use of digital models in the development of oil and gas fields is an effective tool for making informed tactical and strategic decisions to maximize the extraction of hydrocarbon reserves in a field. At the same time, the permanent increase in the share of hard-to-recover reserves leads to an accelerated increase in the role of simulation of reservoir hydrocarbon systems in the development of oil and gas fields. Many gas-condensate fields in Eastern Siberia can be characterized as reservoirs with low permeability and porosity and difficult thermobaric conditions, and, as a result, the issue of improving the efficiency of the development of such reservoirs to increase the cumulative production of gas and condensate is relevant. If the initial reservoir pressure of a gas-condensate field corresponds to the dewpoint pressure, dropout of a significant amount of retrograde condensate is observed when the pressure in the reservoir decreases. Condensate dropout in the pore space of a reservoir leads to a decrease in both the condensate recovery factor (CRF) and the gas recovery factor (GRF). The predictive calculations of the development of a gas-condensate reservoir by vertical and horizontal wells were carried out with the use of the hydrodynamic simulator T-Navigator of a domestic manufacturer Rock Flow Dynamics. The calculations were performed under various process conditions on the example of a gas-condensate field, which is characterized by complicated thermobaric conditions (the initial reservoir pressure corresponds to the dewpoint pressure), while the target process parameter was the amount of condensate dropout in the reservoir. Based on the results of the study, the main conclusion can be drawn. The development of the reservoir by horizontal wells can significantly reduce the reservoir drawdown pressure compared to vertical wells, while the condensate dropout in the reservoir occurs in a larger volume; the condensate becomes immobile and prevents further gas production, reducing the total production of condensate. An increase in reservoir condensate recovery in the course of the development of a gas-condensate reservoir by vertical wells compared to horizontal wells is observed under certain reservoir conditions corresponding to the simulation performed in this study, namely, at low reservoir permeability and porosity and the presence of a saturated gas-condensate system.