Open AccessStudy of the efficiency of trapped gas displacement by non-hydrocarbon gases from water-flooded gas condensate reservoirs
Author(s) -
Serhii Matkivskyi
Publication year - 2020
Publication title -
naftogazova energetika
Language(s) - English
Resource type - Journals
eISSN - 2415-3109
pISSN - 1993-9868
DOI - 10.31471/1993-9868-2020-2(34)-26-33
Subject(s) - carbon dioxide , hydrocarbon , nitrogen , natural gas , petroleum engineering , environmental science , chemistry , geology , organic chemistry
Analyzing industrial data and the results of theoretical studies, it was found that the natural gas recovery factor in water-drive gas reservoirs is about 50-60%. Considering the significant volumes of residual gas reserves trapped by formation water, there is a need to improve existing development technologies and search for optimal ways to increase hydrocarbon recovery under conditions of intensive water encroaching. Additional researches using hydrodynamic simulations were conducted in order to study the efficiency of enhanced recovery of residual gas reserves by injecting non-hydrocarbon gases into productive reservoirs. Based on the 3D reservoir model, the study of carbon dioxide and nitrogen injection into the initial gas-water contact was carried out in order to slow down the breakthrough of formation water into productive reservoir. The study was performed for different injection duration of carbon dioxide and nitrogen into productive reservoir. According to the results of the statistical processing of the calculated data, the optimal duration of the nitrogen injection was determined to be 8,04 months. The ultimate gas recovery factor for the optimal period of nitrogen injection is 58,11%. At the time of the carbon dioxide breakthrough into production wells, the optimal duration of the carbon dioxide injection was determined to be 16,32 months. The ultimate gas recovery factor for the optimal period of carbon dioxide injection is 61,98 %. Based on a comparative analysis of the efficiency of using various types of non-hydrocarbon gases as injection agents into productive reservoirs, the high efficiency of using carbon dioxide for injection into the initial gas-water contact was established. Due to the solubility of carbon dioxide in formation water, the ultimate gas recovery factor is significantly higher compared to using nitrogen as an injection agent.