Influence of technological modes of well operation on the efficiency of regulation of the process of waterflooding of gas condensate reservoirs by carbon dioxide

Abstract

Using the main tools of hydrodynamic modeling, the study of the influence of production well operating parameters on the regulation effectiveness of the gas condensate reservoirs’ flooding process by injection of carbon dioxide at the initial gas-water contact has been carried out. The study has been undertaken for various values ​​of gas flow rate. The simulation results indicate a high technological efficiency of using carbon dioxide as an injection agent. High displacing properties of carbon dioxide provide an increase in the mobility of formation fluids (condensate, oil) and a decrease in the mobility of formation water. The introduction of the technology for injecting carbon dioxide into productive reservoirs at the initial gas-water contact provides the creation of additional hydrodynamic and filtration resistance on the path of formation water movement. Due to which the inflow of formation water into gas-saturated horizons is partially blocked and waterless operation of production wells is ensured during a longer period of further field development. Based on the results of processing the calculated data, the optimal value of the rate of natural gas production has been determined under the carbon dioxide injection into the productive reservoir at the boundary of the gas-water contact, outside of which the gas recovery factor changes insignificantly. At the time of the carbon dioxide breakthrough into the production wells, the optimal production rate of the production well is 55.93 th.m3/day. The predicted gas recovery factor for the given optimal value of the gas production rate is 64.99 %, and when developing for depletion it is 58.34 %. The results of the studies carried out indicate the technological efficiency of the introduction of technologies for injecting carbon dioxide into reservoirs, which are developed in a water drive in order to regulate the process of formation water flow into productive reservoirs and increase the final gas recovery factor.