Мінеральні ресурси України (Mar 2024)
The effect of penetration ratio in gas condensate formations with bottom water on well productivity
Abstract
Waterflooding of hydrocarbon deposits is an urgent problem for the oil and gas industry of Ukraine. In the process of active inflow of both edge-water and bottom water into productive reservoirs, significant hydrocarbon reserves are trapped. This results in low final hydrocarbon recovery factors. The process of watering production wells is natural, but this process must be controlled. To improve the efficiency of development of natural gas fields with bottom water, additional research was conducted using digital modeling. Based on a 3D model, the influence of penetration ratio in gas and water bearing formations on ultimate gas recovery is investigated. For the calculations, the penetration ratio was taken as 20%, 40%, 60%, 80%, and 100%. According to the modeling results, a significant impact of the penetration ratio on the efficiency of hydrocarbon production was found. According to the studies, it was found that with an increase the penetration ratio, the duration of the period of waterless operation of wells decreases. It should be noted that the greater the penetration ratio, the lower the gas recovery factor at the time of the breakthrough of the bottom water to the perforation interval. In addition, according to the studies, it was found that the smaller the penetration ratio, the greater the height of the cone of bottom water, as well as the larger the base of the cone. At full reservoir penetration, there is practically no cone formation process. In this case, the bottom water immediately enters the lower perforations of the production well and thus complicates its operation. In the short term, the flowing process is stopped and the well is shut down due to the failure to ensure the conditions for the removal of the gas-liquid mixture from the bottom hole. Based on the results of the calculations, the optimal penetration ratio in gas condensate deposits with bottom water was determined. According to the statistical processing of the calculated data, the optimal penetration ratio is 60.6%. The results of the research are aimed at improving the theoretical understanding of cone formation processes and for practical application in the mining industry in the development of natural gas fields with bottom water.
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